International Journals

  1. Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Effects of various dopants on properties of GaAs tunneling junctions and p–i–n solar cells,” Jap. J. Appl. Phys. 56, 08MC11-1-5 (2017).
  2. Warakorn Yanwachirakul, Naoya Miyashita, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, Yoshitaka Okada, and Yoshiaki Nakano, “Design of free-barrier InGaAs/GaNAs multiple quantum well solar cells with 1.2 eV energy gap,” Jap. J. Appl. Phys. 56, 08MA04-1-7 (2017).
  3. Hao Xu, Kasidit Toprasertpong, Amaury Delamarre, Hassanet Sodabanlu, Kentaroh Watanabe, Yoshiaki Nakano, and Masakazu Sugiyama, “Effect of low-V/III-ratio metalorganic vapor-phase epitaxy on GaAs solar cells,” Jap. J. Appl. Phys. 56, 08MC06-1-6 (2017).
  4. Cai Liu, Akihito Kumamoto, Michihiro Suzuki, Hongbo Wang, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Effects of hydrogen etching on stress control in AlN interlayer inserted GaN MOVPE on Si,” Semicond. Sci. Technol. 32, 075003 (2017)
  5. Hongbo Wang, Hassanet Sodabanlu, Yoshiaki Daigo, Takuya Seino, Takashi Nakagawa, and Masakazu Sugiyama, “Improved luminescence from InGaN/GaN MQWs by reducing initial nucleation density using sputtered AlN on sapphire substrate,” J. Cryst. Growth 465, 12-17 (2017).
  6. Hirofumi Cho, Kasidit Toprasertpong, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Stability and controllability of InGaAs/GaAsP wire-on-well (WoW) structure for multi-junction solar cells,” J. Cryst. Growth 464, 86-93 (2017).
  7. Masakazu Sugiyama, Hiromasa Fujii, Takumi Katoh, Kasidit Toprasertpong, Hassanet Sodabanlu, Kentaroh Watanabe, Diego Alonso-Alvarez, Nicholas J. Ekins-Daukes, and Yoshiaki Nakano, “Quantum wire-on-well (WoW) cell with long carrier lifetime for efficient carrier transport,” Prog. Photovoltaics: Research and Applications 24, 1606-1614 (2016).
  8. Hongbo Wang, Hassanet Sodabanlu, Yoshiaki Daigo, Takuya Seino, Takashi Nakagawa, and Masakazu Sugiyama, “Initial growth control of GaN on Si with physical-vapor-deposition-AlN seed layer for high-quality GaN templates ,” Appl. Phys. Express 9, 055503 (2016).
  9. Kentaroh Watanabe, Tomoyuki Inoue, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Thin-film solar cells with InGaAs/GaAsP multiple quantum wells and a rear surface etched with light trapping micro-hole array,” Jap. J. Appl. Phys. 54, 08KA13-1-5 (2015).
  10. Hiromasa Fujii, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Thickness-modulated InGaAs/GaAsP superlattice solar cells on vicinal substrates,” J. Appl. Phys. 117, 154501 (2015).
  11. Hiromasa Fujii, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Low-temperature MOVPE using TEGa for suppressed layer undulation in InxGa1-xAs/GaAs1-yPy superlattice on vicinal substrates,” J. Cryst. Growth 414, 3-9 (2015).
  12. Akio Higo, Takayuki Kiba, Yosuke Tamura, Cedric Thomas, Junichi Takayama, Yunpeng Wang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, Ichiro Yamashita, Akihiro Murayama, and Seiji Samukawa, “Light-Emitting Devices Based on Top-down Fabricated GaAs Quantum Nanodisks,” Scientific Reports 5, 9371 (2015).
  13. Daniel J. Farrell, Hassanet Sodabanlu, Yunpeng Wang, Masakazu Sugiyama, and Yoshitaka Okada, “Can a hot-carrier solar cell also be an efficient up-converter?,” IEEE J. Photovoltaics 5, 571-6 (2015).
  14. Benoît Behaghel, Ryo Tamaki, Nicolas Vandamme, Kentaroh Watanabe, Christophe Dupuis, Nathalie Bardou, Hassanet Sodabanlu, Andrea Cattoni, Yoshitaka Okada, Masakazu Sugiyama, Stéphane Collin, and Jean-François Guillemoles, “Absorption enhancement through Fabry-Pérot resonant modes in a 430 nm thick InGaAs/GaAsP multiple quantum wells solar cell,” Appl. Phys. Lett, 106, 081107 (2015).
  15. Hiromasa Fujii, Kasidit Toprasertpong, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “InGaAs/GaAsP superlattice solar cells with reduced carbon impurity grown by low-temperature metal-organic vapor phase epitaxy using triethylgallium,” J. Appl. Phys. 116, 203101 (2014).
  16. Kentaroh Watanabe, Yunpeng Wang, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Strain effect for different phosphorus content of InGaAs/GaAsP super-lattice in GaAs p-i-n single junction solar cell,” J. of Cryst. Growth 401, 712-716 (2014).
  17. Diego Alonso-Álvarez, Thomas, Tomos Thomas, Markus Führer, Nicholas P. Hylton, Ned J. Ekins-Daukes, David Lackner, Simon P. Philipps, Andreas W. Bett, Hassanet Sodabanlu, Hiromasa Fujii, Kentaroh Watanabe, Masakazu Sugiyama, Lucia Nasi, and Marco Campanini, “InGaAs/GaAsP strain balanced multi-quantum wires grown on misoriented GaAs substrates for high efficiency solar cells,” Appl. Phys. Lett. 105, 083124 (2014).
  18. Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Growth of InGaAs/GaAsP multiple quantum well solar cells on mis-orientated GaAs substrates,” J. of Appl. Phys. 115, 233104 (2014).
  19. Cai Liu, Hongbo Wang, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Void formation during GaN MOVPE on Si (111) employing low temperature AlN interlayers,” Physica Status Solidi (C) 11, 293-296 (2014).
  20. Cai Liu, Akihito Kumamoto, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “In-situ growth condition analysis of AlN interlayers for wafer curvature control in GaN MOVPE on Si (111),” Physica Status Solidi (C) 11, 598-603 (2014).
  21. Kentaroh Watanabe, Boram Kim, Tomoyuki Inoue, Hassanet Sodabanlu, Masakazu Sugiyama, Masanao Goto, Shinya Hayashi, Kenjiro Miyano, and Yoshiaki Nakano, “Thin Film InGaAs/GaAsP MQWs Solar Cell with Backside Nano-Imprinted Pattern for Light-Trapping,” IEEE J. Photovoltaics 4, 1086-1090 (2014).
  22. Manish Mathew, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “ Orange/yellow InGaN/AlN nanodisk light emitting diodes,” Physica Status Solidi (C) 10, 1525-1528 (2013).
  23. Cai Liu, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Thickness optimization of GaN layers by in-situ observation of GaN MOVPE on Si (111),” Physica Status Solidi (C) 10, 1541-1544 (2013).
  24. Nicholas P. Hylton, Xiaofeng Li, Vincenzo Giannini, Kan-Hua Lee, N.J. Ekins-Daukes, Josine Loo, Dries Vercruysse, Pol Van Dorpe, Hassanet Sodabanlu, Masakazu Sugiyama, and Stefan Maier, “Loss mitigation in plasmonic solar cells: aluminium nanoparticles for broadband photocurrent enhancements in GaAs photodiodes,” Scientific Reports 3, 2874 (2013).
  25. Kazehiko Anazawa, Hassanet Sodabanlu, Katsushi Fujii, Yoshiaki Nakano, and Masakazu Sugiyama, “Growth of strain-compensated InGaN/AlN multiple quantum wells on GaN by MOVPE,” J. Cryst. Growth 370, 82-86 (2013).
  26. Shaojun Ma, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Optimized interfacial management for InGaAs/GaAsP strain-compensated superlattice structure,” J. Cryst. Growth 370, 157-62 (2013).
  27. Masakazu Sugiyama, Yunpeng Wang, Hiromasa Fujii, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited paper) “A quantum-well superlattice solar cell for enhanced current output and minimized drop in open-circuit voltage under sunlight concentration,” J. Physics D: Appl. Phys. 46, 024001 (2013).
  28. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Impact of Strain Accumulation on InGaAs / GaAsP Multiple Quantum Wells Solar Cells: Direct Correlation Between In Situ Strain Measurement and Cell Performances,” Jpn. J. Appl. Phys.51, n 10 PART 2, October, Photovoltaic Science and Engineering 10ND16 (2012).
  29. Shaojun Ma, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Optimization of gas-switching sequence for InGaAs/GaAsP superlattice structures using in situ wafer curvature monitoring,” Jpn. J. Appl. Phys. 51, n 10 PART 2, October, Photovoltaic Science and Engineering 10ND09 (2012).
  30. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Effects of Background Zn Doping on the Performance of MOVPE-Grown InGaAs/GaAsP Multiple Quantum Wells Solar Cells,” Jpn. J. Appl. Phys. 51, n 10 PART 2, October, Photovoltaic Science and Engineering 10ND15 (2012).
  31. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Effects of Strain on the Performance of InGaAs/GaAsP Multiple-Quantum-Well Solar Cells Correlated with In situ Curvature Monitoring,” Appl. Phys. Express 5, 062301 (2012).
  32. Yunpeng Wang, Yu Wen, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “A Superlattice Solar Cell With Enhanced Short-Circuit Current and Minimized Drop in Open-Circuit Voltage,” IEEE J. Photovoltaics 2, 387-392 (2012).
  33. Shaojun Ma, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Effect of hetero-interfaces on in situ wafer curvature behavior in InGaAs/GaAsP strain-balanced MQWs,” J. Cryst. Growth 352, 245-248 (2012).
  34. Shaojun Ma, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Strain-compensation measurement and simulation of InGaAs/GaAsP multiple quantum wells by metal organic vapor phase epitaxy using wafer-curvature,” J. Appl. Phys. 110, 113501 (2011).
  35. Hassanet Sodabanlu, Jeong-Seung Yang, Takuo Tanemura, Masakazu Sugiyama, Yukihiro Shimogaki, and Yoshiaki Nakano, “Intersubband absorption saturation in AlN-based waveguide with GaN/AlN multiple quantum wells grown by metalorganic vapor phase epitaxy,” Appl. Phys. Lett. 99, 151102 (2011).
  36. Jeong-Seung Yang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Fabrication of n-type GaN layers by the pulse injection method at 950C for intersubband devices,” Electrochemical and Solid-State Lett. 14, H143-H145 (2011).
  37. Jeong-Seung Yang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Intersubband transition at 1.55 μm in AlN/GaN multiple quantum wells by metal organic vapor phase epitaxy using the pulse injection method at 770°C,” J. Cryst. Growth 314, 252-7 (2011).
  38. Hassanet Sodabanlu, Jeong-Seung Yang, Masakazu Sugiyama, Yukihiro Shimogaki, and Yoshiaki Nakano, “Strain effects on the intersubband transitions in GaN/AlN multiple quantum wells grown by low-temperature metal organic vapor phase epitaxy with AlGaN interlayer,” Appl. Phys. Lett. 95, 161908 (2009).
  39. Jeong-Seung Yang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Blueshift of intersubband transition wavelength in AlN/GaN multiple quantum wells by low temperature metal organic vapor phase epitaxy using pulse injection method,” Appl. Phys. Lett. 95, 162111 (2009).
  40. Hassanet Sodabanlu, Jeong-Seung Yang, Masakazu Sugiyama, Yukihiro Shimogaki, and Yoshiaki Nakano, “Intersubband Transition at 1.52 µm in GaN/AlN Multiple Quantum Wells Grown by Metal Organic Vapor Phase Epitaxy,” Appl. Phys. Express 2 (2009) 061002.
  41. Jeong-Seung Yang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Fabrication of Abrupt AlN/GaN Multi Quantum Wells by Low Temperature Metal Organic Vapor Phase Epitaxy,” Appl. Phys. Express 2 (2009) 051004.
  42. Jeong-Seung Yang, Hassanet Sodabanlu, I. Waki, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Process design of the pulse injection method for low-temperature metal organic vapor phase epitaxial growth of AlN at 800°C,” J. Cryst. Growth 311, 383-8 (2009).
  43. Jeong-Seung Yang, Hassanet Sodabanlu, I. Waki, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Low Temperature Metal Organic Vapor Phase Epitaxial Growth of AlN by Pulse Injection Method at 800 °C,” Jpn. J. Appl. Phys. 46, L927-L929 (2007).

International conferences (proceedings and presentations)

  1. Mohiyuddin Kazi, Samir Ghosh, Hassanet Sodabanlu, Takuo Tanemura, and Yoshiaki Nakano, “Monolithic polarization controller with InGaAlAs/InAlAs multiple-quantum-well phase shifter,” 29th International Conference on Indium Phosphide and Related Materials (IPRM), pp. 1-2, Berlin, May 14-18 (2017).
  2. Akio Higo, Yafeng Chen, Takayuki Kiba, Cedric Thomas, Junichi Takayama, Akira Imoto, Soushi Miyazaki, Takeshi Kamikawa, Masahiro Tanaka, Ichiro Yamashita, Yunpeng Wang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, Akihiro Murayama, and Seiji Samukawa, “Fabrication of GaAs quantum nanodisk and its optical response by bio-template, neutral beam etching and asymmetric AlGaAs barrier regrowth,” SPIE Conference 10116, MOEMS and Miniaturized Systems XVI (Part of SPIE Photonics West/OPTO), Paper 10116-25, San Francisco, California, February 1 (2017).
  3. Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Effect of various dopants on properties of GaAs tunnelling junction and p-i-n solar cell,” 26th International Photovoltaic Science and Engineering Conference (PVSEC), Marina Bay Sands, October 24-28 (2016).
  4. Hao Xu, Kasidit Toprasertpong, Amaury Delamarre, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “GaAs solar cells with low-V/III-ratio MOVPE for low-cost power generation,” 26th International Photovoltaic Science and Engineering Conference (PVSEC), Marina Bay Sands, October 24-28 (2016).
  5. Kentaroh Watanabe, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Epitaxial growth and characterization of the direct doped PN junction with InGaAs/GaAsP superlattice,” 26th International Photovoltaic Science and Engineering Conference (PVSEC), Marina Bay Sands, October 24-28 (2016).
  6. Warakorn Yanwachirakul, Naoya Miyashita, Hassanet Sodabunlu, Kentaroh Watanabe, Masakazu Sugiyama, Yoshitaka Okada, and Yoshiaki Nakano, “Design structure of free-barrier InGaAs/GaNAs multiple quantum well solar cells with 1.2 eV energy gap,” 26th International Photovoltaic Science and Engineering Conference (PVSEC), Marina Bay Sands, October 24-28 (2016).
  7. Masakazu Sugiyama, Hirofumi Cho, Toprasertpong Kasidit, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited Talk) “InGaAs/GaAsP quantum wells and wires for high-efficiency photovoltaic applications,” 16th International Conference on Nanotechnology (IEEE-NANO), pp. 519-520, Sendai, August 22-25 (2016).
  8. Masakazu Sugiyama, Toprasatpong Kasidit, Hiromasa Fujii, Hirofumi Cho, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited) “Metalorganic vapor-phase epitaxy of InGaAs/GaAsP quantum wells and wires for high-efficiency photovoltaic applications,” 18th International Conference on Crystal Growth and Epitaxy (ICCGE), Nagoya, August 7-12 (2016).
  9. Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Growth of C-doped GaAs in planetary MOVPE reactor using tertiarybutyl-arsine and carbon-tetrachloride,” 18th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE), p. 40, San Diego, California, July 10-15 (2016).
  10. Hirofumi Cho, Kasidit Toprasertpong, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Stability and controllability of InGaAs/GaAsP wire-on-well (WoW) structure for multi-junction solar cells,” 18th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE), pp. 83-84, San Diego, California, July 10-15 (2016).
  11. Hirofumi Cho, Kasidit Toprasertpong, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Stability and controllability of InGaAs/GaAsP wire-on-well (WoW) structure for multi-junction solar cells,” 35th Electronic Materials Symposium (EMS), pp. 39-40, Biwako, Shiga, July 6-8 (2016).
  12. Kentaroh Watanabe, Tomoyuki Inoue, Kasidit Toprasertpong, Amaury Delamarre, Hassanet Sodabanlu, Jean-Francois Guillemoles, Masakazu Sugiyama, and Yoshiaki Nakano: “Optical analysis of the photon recycling effect in InGaAs/GaAsP multiple quantum well solar cell with light trapping structure,” 43rd IEEE Photovoltaic Specialists Conference (PVSC), pp. 1268-1272, Portland, Oregon, June 6-10 (2016).
  13. Kentaroh Watanabe, Hassanet Sodabanlu, Kasidit Toprasertpong, Tomoyuki Inoue, Amaury Delamarre, Masakazu Sugiyama, and Yoshiaki Nakano, “ Novel design of multiple-quantum-wells structure for improved tandem III-V solar cells,” The Energy, Materials, and Nanotechnology (EMN) Photovoltaics Meeting, B25, Hong Kong, January 20 (2016).
  14. Kentaroh Watanabe, Tomoyuki Inoue, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Self-organized texture of GaAs by wet etching for light trapping in MQWs solar cells,” 31st European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), pp. 181-184, Hamburg, September 14-18 (2015).
  15. Masakazu Sugiyama, Hiromasa Fujii, Takumi Katoh, Kasidit Toprasertpong, Hassanet Sodabanlu, Kentaroh Watanabe, Diego Alonso-Alvarez, Nicholas J. Ekins-Daukes, and Yoshiaki Nakano, “Quantum wire-on-well (WoW) cell with long carrier lifetime for efficient carrier transport,” 31st European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), pp. 42-47, Hamburg, September 14-18 (2015).
  16. Yoshiaki Nakano, Masakazu Sugiyama, Kentaroh Watanabe, and Hassanet Sodabanlu, (Keynote Speech) “Semiconductor nanostructures for multiple junction high-efficiency photovoltaic cells,” Abstract Digest, 5th International Workshop on Epitaxial Growth and Fundamental Properties of Semiconductor Nanostructures (SemiconNano), p. 1, Taiwan, September 6-11 (2015).
  17. Yoshiaki Nakano, Masakazu Sugiyama, Kentaroh Watanabe, and Hassanet Sodabanlu, (Invited Talk) “Quantum microstructures for high-efficiency photovoltaic cells,” Abstract Book, 2015 International Nano-Optoelectronics Workshop (iNOW), pp. 102-103, Tokyo, August 3-7 (2015).
  18. Kazi Mohiyuddin, Yuto Kawabata, Hassanet Sodabanlu, Yunpeng Wang, Kentaro Suzuki, Masaru Zaitsu, Takuo Tanemura, and Yoshiaki Nakano, “Fabrication of polarization-converter-integrated InGaAsP/InP MQW photodetector,” Abstract Book, 2015 International Nano-Optoelectronics Workshop (iNOW), pp. 96-97, Tokyo, August 3-7 (2015).
  19. Hassanet Sodabanlu, Hiromasa Fujii, Kentaroh Watanabe, Ryusuke Onitsuka, Takaaki Agui, Hiroyuki Juso, Tatsuya Takamoto, David Lackner, Frank Dimroth, Andreas W. Bett, Masakazu Sugiyama, and Yoshiaki Nakano, “Lattice-matched 3-junction cell with 1.2-eV InGaAs/GaAsP superlattice middle cell for improved current matching,” 42th IEEE Photovoltaic Specialists Conference (PVSC), New Orleans, June 14-19 (2015).
  20. Kenichi Yoshikawa, Akio Higo, Chang-Yong Lee, Yosuke Tamura, Cedric Thomas, Takayuki Kiba, Shintaro Ishii, Hassanet Sodabanlu, Yunpeng Wang, Masakazu Sugiyama, Yoshiaki Nakano, Ichiro Yamashita, Akihiro Murayama, and Seiji Samukawa, “Fabrication of InGaAs quantum nanodisks array by using bio-template and top-down etching processes,” 14th IEEE International Conference on Nanotechnology (IEEE-NANO), p. 211-214, November 26 (2014).
  21. Yosuke Tamura, Akio Higo, Takayuki Kiba, Cedric Thomas, Yunpeng Wang, Hassanet Sodabanlu, Ichiro Yamashita, Masakazu Sugiyama, Yoshiaki Nakano, Akihiro Murayama, and Seiji Samukawa, “Narrow line-width photoluminescence spectrum of GaAs nanodisks fabricated using bio-template ultimate top-down processes,” 14th IEEE International Conference on Nanotechnology (IEEE-NANO), p. 221-224, November 26 (2014).
  22. Akio Higo, Takayuki Kiba, Yosuke Tamura, Cedric Thomas, Yunpeng Wang, Hassanet Sodabanlu, Junichi Takayama, Masakazu Sugiyama, Yoshiaki Nakano, Yoshiaki, Ichiro Yamashita, Akihiro Murayama, and Seiji Samukawa, “Quantum GaAs nanodisk light emitting diode fabricated by ultimate top-down neutral beam etching, 2014 IEEE International Semiconductor Laser Conference (ISLC), p. 133-134, December 16 (2014).
  23. Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Efficiency Improvement of InGaAs/GaAsP Multiple Quantum Well Solar Cells on Mis-Oriented GaAs Substrates by Pulse Injection MOVPE,” 6th World Conference on Photovoltaic Energy Conversion (WCPEC), 5WeO.3.5, Kyoto, November 23-27 (2014).
  24. Yunpeng Wang, Hassanet Sodabanlu, Hiromasa Fujii, Kasidit Toprasertpong, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “InGaP-Based Multiple-Quantum-Well Solar Cell Fabricated Using Metal-Organic-Vapor –Phase-Epitaxy,” 6th World Conference on Photovoltaic Energy Conversion (WCPEC), 1WePo.1.18, Kyoto, November 23-27 (2014).
  25. Kentaroh Watanabe, Tomoyuki Inoue, Hassanet Sodabanlu, Yunpeng Wang, Masakazu Sugiyama, and Yoshiaki Nakano, “Thin-Film InGaAs/GaAsP MQWs Solar Cell with Dielectric Micro-Hole Array Structure for Light Trapping Effect,” 6th World Conference on Photovoltaic Energy Conversion (WCPEC), 1WeO.2.3, Kyoto, November 23-27 (2014).
  26. Daniel J. Farrell, Hassanet Sodabanlu, Yunpeng Wang, Masakazu Sugiyama, and Yoshitaka Okada, “Can a hot-carrier solar cell also be an efficient up-converter?,” 40th IEEE Photovoltaic Specialists Conference (PVSC), Denver, June 8-13 (2014).
  27. Benoît Behaghel, Ryo Tamaki, Nicolas Vandamme, Kentaroh Watanabe, Christophe Dupuis, Nathalie Bardou, Hassanet Sodabanlu, Andrea Cattoni, Yoshitaka Okada, Masakazu Sugiyama, Stéphane Collin, and Jean-François Guillemoles, “Four-fold MQWs Absorption Enhancement in a 430 nm Thick InGaAs/GaAsP MQWs Solar Cell,” 40th IEEE Photovoltaic Specialists Conference (PVSC), p. 0099-0101, Denver, June 8-13 (2014).
  28. Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Theoretical Study of Hot-Carrier Solar Cell with InGaAs/GaAsP Multiple Quantum Well Absorber,” 29th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 322-324, Amsterdam, September 22-26 (2014).
  29. Hiromasa Fujii, Kasidit Toprasertpong, Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “InGaAs/GaAsP Superlattice Solar Cells on Vicinal Substrates for Current-Matched Triple Junction Cells on Ge,” 29th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 1986-1990, Amsterdam, September 22-26 (2014).
  30. Yunpeng Wang, Hassanet Sodabanlu, Hiromasa Fujii, Kasidit Toprasertpong, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Thermionic/tunneling Carrier Collection from MQWs: How Different Mechanisms Affect Solar Cell Performance under 1 Sun and Concentration,” 29th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 310-312, Amsterdam, September 22-26 (2014).
  31. Masakazu Sugiyama, Hiromasa Fujii, Kasidit Toprasertpong, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited Talk) “Nanoepitaxial Structures for the Efficiency Enhancement of Multijunction Solar Cells,” Nano and Giga Challenges in Electronics, Photonics and Renewable Energy, Phoenix, March 10-14 (2014).
  32. Kentaroh Watanabe, Hassanet Sodabanlu, Yunpeng Wang, Masakazu Sugiyama, and Yoshiaki Nakano, “Light-biased Quantum Efficiency Analysis of the InGaAs/GaAsP Multiple Quantum Wells Solar Cells,” 23rd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-9, Taipei, October 28 - November 1 (2013).
  33. Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Efficiency of InGaAs/GaAsP Multiple Quantum Well Solar Cells on Various Mis-oriented GaAs Substrates under Concentrated Light,” 23rd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-12, Taipei, October 28 - November 1 (2013).
  34. Hiromasa Fujii, Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “In-situ Reflectance Monitoring in MOVPE Growth of InGaAs/GaAsP uperlattice on Misoriented GaAs Substrate,” 23rd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-14, Taipei, October 28 - November 1 (2013).
  35. Yunpeng Wang, Hassanet Sodabanlu, Hiromasa Fujii, Kasidit Toprasertpong, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Investigation on the Role of Inserted Ultrathin GaAs Layer in a Strain Balanced Superlattice Solar Cell,” 23rd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-15, Taipei, October 28 - November 1 (2013).
  36. Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Shaojun Ma, Masakazu Sugiyama, and Yoshiaki Nakano, “A Novel Design in Strain-Balanced Super-Lattice Solar Cell towards an Efficient Carrier Transport and Breaking the Strain-Balance Bottleneck of Deep Well Structure,” 28th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 28-30, Paris, September 30- October 4 (2013).
  37. Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Efficiency of InGaAs/GaAsP Multiple Quantum Well Solar Cell on Various Misoriented GaAs Substrates Grown by Metalorganic Vapor Phase Epitaxy,” 28th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 286-248, Paris, September 30- October 4 (2013).
  38. Nicholas P. Hylton, X. Li, Vincenzo Giannini, Kan-Hua Lee, Ned J. Ekins-Daukes, Josine Loo, Dries Vercruysse, Pol Van Dorpe, Hassanet Sodabanlu, Masakazu Sugiyama, and Stefan A. Maier, “Broadband Absorption Enhancements Using Scattering Al Nanoparticle Arrays,” 28th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 11-13, Paris, September 30- October 4 (2013).
  39. Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Absorption coefficient of InGaAs/GaAsP multiple quantum wells on mis-oriented GaAs for photovoltaic application,” 2013 The Japan Society of Applied Physics and the Materials Research Society (JSAP-MRS) Joint Symposia, 16p-PM2-9, Kyoto, September 16-18 (2013).
  40. Kentaroh Watanabe, Hassanet Sodabanlu, Yunpeng Wang, Masakazu Sugiyama, and Yoshiaki Nakano, “Enhanced power conversion efficiency in InGaAs/GaAsP multiple quantum well solar cells,” 2013 The Japan Society of Applied Physics and the Materials Research Society (JSAP-MRS) Joint Symposia, 18a-M2-3, Kyoto, September 16-18 (2013).
  41. Masakazu Sugiyama, Kentaroh Watanabe, Yunpeng Wang, Hassanet Sodabanlu, Hiromasa Fujii, and Yoshiaki Nakano, “ Can quantum wells provide efficiency gain for a single-junction cell?,” 2013 The Japan Society of Applied Physics and the Materials Research Society (JSAP-MRS) Joint Symposia, 18a-M2-4, Kyoto, September 16-18 (2013).
  42. Yunpeng Wang, Hiromasa Fujii, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Investigation on the role of inserted ultra-thin GaAs layer in a strain balanced superlattice solar cell,” 2013 The Japan Society of Applied Physics and the Materials Research Society (JSAP-MRS) Joint Symposia, 18a-M2-8, Kyoto, September 16-18 (2013).
  43. Manish Mathew, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Monolithic cool white light emitting diodes based on InGaN/AlN nanodisks,” 2013 The Japan Society of Applied Physics and the Materials Research Society (JSAP-MRS) Joint Symposia, 18p-M6-11, Kyoto, September 16-18 (2013).
  44. Naruaki Itoh, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Simulation of intersubband transition in GaN-AlN multiple quantum wells,” 12th International Conference on Intersubband transition in quantum wells (ITQW), Volume: XV-7, p. 1-2, Lake George, September 16-20 (2013).
  45. Kentaroh Watanabe, Yunpeng Wang, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Strain effect for different phosphorus content of InGaAs/GaAsP super-lattice in GaAs p-i-n single junction solar cell,” 17th International Conference on Crystal Growth and Epitaxy (ICCGE), Volume: FrO2.5, p. 388-392, Warsaw, August 11-16 (2013).
  46. Hongbo Wang, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “HT GaN Growth on Patterned AIN Nucleation Layer Using ICP O2 Plasma Treatment,” 10th International Conference on Nitride Semiconductors (ICNS), AP3.72, Washington DC, August 25-30 (2013).
  47. Manish Mathew, Hassanct Sodabanlul, Masakazu Sugiyama, and Yoshiaki Nakano, “Monolithic Cool White Light Emitting Diodes Based on AlN Islands,” 10th International Conference on Nitride Semiconductors (ICNS), B5.03, Washington DC, August 25-30 (2013).
  48. Kentaroh Watanabe, Yunpeng Wang, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Analysis for current-voltage characteristics of the InGaAs/GaAsP super-lattice solar cells under optical concentration,” AIP Conference Proceedings, v 1556, p. 62-6, 2013.
  49. Nicholas P. Hylton, Xiaofeng Li, Vincenzo Giannini, Kan-Hua Lee, Ned J. Ekins-Daukes, Josine Loo, Dries Vercruysse, Pol Van Dorpe, Hassanet Sodabanlu, Masakazu Sugiyama, and Stefan A. Maier, “Al Nanoparticle Arrays for Broadband Absorption Enhancements in GaAs Photodiodes,” 39th IEEE Photovoltaic Specialists Conference (PVSC), p. 14, Tampa, June 16-21 (2013).
  50. Hassanet Sodabanlu, Yunpeng Wang, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Metalorganic Vapor Phase Epitaxy Growth of Dual Junction Solar Cell with InGaAs/GaAsP Superlattice on Ge,” 39th IEEE Photovoltaic Specialists Conference (PVSC), p. 103, Tampa, June 16-21 (2013).
  51. Yunpeng Wang, Kentaroh Watanabe, Hassanet Sodabanlu, Shaojun Ma, Hiromasa Fujii, Kasidit Toprasertpong, Masakazu Sugiyama, and Yoshiaki Nakano, “A superlattice solar cell for enhanced current output and minimized drop in open-circuit voltage under sunlight concentration,” 39th IEEE Photovoltaic Specialists Conference (PVSC), p. 109, Tampa, June 16-21 (2013).
  52. Shaojun Ma, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Evaluation of asymmetric tunneling-assisted structure for InGaAs/GaAsP MQWs solar cell,” 39th IEEE Photovoltaic Specialists Conference (PVSC), p. 483, Tampa, June 16-21 (2013).
  53. Kentaroh Watanabe, Boram Kim, Tomoyuki Inoue, Hassanet Sodabanlu, Masanao Goto, Shinya Hayashi, Masakazu Sugiyama, Kenjiro Miyano, and Yoshiaki Nakano, “Thin film InGaAs/GaAsP MQWs solar cell with backside nano-imprinted pattern for light trapping,” 39th IEEE Photovoltaic Specialists Conference (PVSC), p. 485, Tampa, June 16-21 (2013).
  54. Masakazu Sugiyama, Hiromasa Fujii, Kasidit Toprasertpong, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited Talk) “Strain-balanced quantum-well superlattice for higher efficiency of III-V solar cells,” E-MRS spring meeting, D.XVI.1, Strasbourg, May 27-31(2013) .
  55. Cai Liu, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Void Formation during GaN MOVPE on Si (111) Employing Low Temperature AlN Interlayers,” E-MRS spring meeting, L 13-4, Strasbourg, May 27-31(2013) .
  56. Manish Mathew, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Long wavelength InGaN/AlN nanodisk light emitting diode,” E-MRS spring meeting, L P226, Strasbourg, May 27-31(2013) .
  57. Masakazu Sugiyama, Kentaroh Watanabe, Yunpeng Wang, Hassanet Sodabanlu, Hiromassa Fujii, Boram Kim, Kenjiro Miyano, and Yoshiaki Nakano, (Invited Talk) “Efficiency gain of quantum-well solar cells by light-trapping structure and sunlight concentration,” SPIE Photonic West 2013, Physics, Simulation, and Photonic Engineering of Photovoltaic Devices II, 8620-48, San Francisco, February 2-7 (2013).
  58. Masakazu Sugiyama, Hiromasa Fujii, Yu Wen, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited Talk) “InGaAs/GaAsP quantum-well superlattice solar cell for better carrier collection and higher efficiency,” 2012 Conference on Optoelectronic and Microelectronic Materials & Devices (COMMAD), p. 125-6, Melbourne, December 12-14 (2012).
  59. Yunpeng Wang, Shaojun Ma, Hassanet Sodabanlu, Hiromasa Fujii, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Smart interface management to implement a high quality strain balanced super-lattice solar cell,” 22nd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-4, Hangzhou, November 05-09 (2012).
  60. Kentaroh Watanabe, Kasidit Toprasertpong, Hiromasa Fujii, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Temperature-dependent photoluminescence analysis for InGaAs/GaAsP multiple quantum wells solar cell,” 22nd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-30, Hangzhou, November 05-09 (2012).
  61. Shaojun Ma, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “InGaAs/GaAsP MQWs solar cell with tunneling assisted structure for enhancing carrier transportation,” 22nd International Photovoltaic Science and Engineering Conference (PVSEC), 4-O-32, Hangzhou, November 05-09 (2012).
  62. Hassanet Sodabanlu, Shaojun Ma, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Chirped distributed bragg reflector for enhancing light absorption in InGaAs/GaAs multiple-quantum-well single-junction solar cells,” 22nd International Photovoltaic Science and Engineering Conference (PVSEC), 4-P-29, Hangzhou, November 05-09 (2012).
  63. Kazehiko Anazawa, Hassanet Sodabanlu, Katsushi Fujii, Yoshiaki Nakano, and Masakazu Sugiyama, “Impact of accumulated stress on the quality of InGaN/AlN MQWs on GaN grown by MOVPE,” International Workshop on Nitride Semiconductors 2012 (IWN), TuP-GR-34, Sapporo, October 14-19 (2012).
  64. Hongbo Wang, Hassanet Sodabanlu, Y. Daigo, T. Nakagawa, and Masakazu Sugiyama, “Underlayer dependence of luminescence property for InGaN grown by MOVPE,” International Workshop on Nitride Semiconductors 2012 (IWN), TuP-GR-30, Sapporo, October 14-19 (2012).
  65. Yunpeng Wang, Kentaroh Watanabe, Hiromasa Fujii, Hassanet Sodabanlu, Masakazu Sugiyama, and Yoshiaki Nakano, “Observation of a Strong Open-Circuit Voltage Enhancement in a Super-Lattice Solar Cell under Concentration: A Potential Scenario for a High Efficiency Single Junction Cell,” 27th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 41-43, Frankfurt, September 24-28 (2012).
  66. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Correlation between Performance of InGaAs/GaAsP Multiple Quantum Well Solar Cells and Average Strain Evaluated by Wafer Curvature and X-Ray Reciprocal Space Mapping,” 27th European Photovoltaic Solar Energy Conference and Exhibition (EU-PVSEC), p. 325-327, Frankfurt, September 24-28 (2012).
  67. Masakazu Sugiyama, Hiromasa Fujii, Yu Wen, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Invited Talk) “Enhancement of Carrier Collection for High-Efficiency Quantum-Well Solar Cells,” XXI International Materials Research Congress, 6C-6, Cancun, August 12-17 (2012).
  68. Masakazu Sugiyama, Yunpeng Wang, Hiromasa Fujii, Hassanet Sodabanlu, Kentaroh Watanabe, and Yoshiaki Nakano, (Plenary Talk) “Efficiency improvement of III-V solar cells using quantum-well superlattice,” International Conference of Young Researchers on Advanced Materials 2012 (ICYRAM), EM1-M-09, Singapore, July 1-6 (2012).
  69. Kazehiko Anazawa, Hassanet Sodabanlu, Katsushi Fujii, Yoshiaki Nakano, and Masakazu Sugiyama, “Growth of Strain-Compensated InGaN/AlN MQWs on GaN by MOVPE,” 16th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE), MoA3-5, Busan, May 20-25 (2012).
  70. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Correlation Between in SITU Wafer's Curvature and the Performance of InGaAs/GaAsP Multiple Quantum Wells Solar Cells,” 16th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE), TuP-101, Busan, May 20-25 (2012).
  71. Kentaroh Watanabe, Hassanet Sodabanlu, Shaojun Ma, Masakazu Sugiyama, and Yoshiaki Nakano, “In-Situ Curvature Monitoring of the MOVPE Grown InGaAs/GaAs Compressive Strained Multiple Quantum Wells Solar Cells,” 16th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE), TuP-105, Busan, May 20-25 (2012).
  72. Kentaroh Watanabe, Boram Kim, Hassanet Sodabanlu, Masanao Goto, Keisuke Nakayama, Shinya Hayashi, Masakazu Sugiyama, Kenjiro Miyano, and Yoshiaki Nakano, “Light-Trapping Structure with Backside Scatterer for Enhanced Photo-Absorption by Quantum Structures,” 38th IEEE Photovoltaic Specialists Conference (PVSC), p. 000113-000117Austin, June 3-8 (2012).
  73. Shaojun Ma, Hassanet Sodabanlu, Yunpeng Wang, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “InGaAs/GaAsP Asymmetric Quantum Wells for Enhancing Carrier Escape Through Resonant Tunneling,” 38th IEEE Photovoltaic Specialists Conference (PVSC), p. 001908-001910, Austin, June 3-8 (2012).
  74. Yunpeng Wang, Shaojun Ma, Hassanet Sodabanlu, Hiromasa Fujii, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “A Multi-Step Superlattice Solar Cell with Enhanced Sub-Band Absorption and Open Circuit Voltage,” 38th IEEE Photovoltaic Specialists Conference (PVSC), p. 001940-001943, Austin, June 3-8 (2012).
  75. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Carrier Sweep-Out Time in InGaAs/GaAsP Multiple Quantum Well Solar Cells by Time-Resolved Photoluminescence: Effects of Well Depth and Barrier Thickness,” 38th IEEE Photovoltaic Specialists Conference (PVSC), p. 001922-001925, Austin, June 3-8 (2012).
  76. Kentaroh Watanabe, Yunpeng Wang, Hassanet Sodabanlu, Shaojun Ma, Boram Kim, Masakazu Sugiyama, and Yoshiaki Nakano, “Open-circuit-voltage enhancement of the III-V super-lattice solar cells under optical concentration,” AIP Conference Proceedings 1477, 40-3 (2012).
  77. Masakazu Sugiyama, Yunpeng Wang, Hassanet Sodabanlu, Shaojun Ma, Hiromasa Fujii, Kentaroh Watanabe, and Yoshiaki Nakano, “Defect Management in III-V Nanostructure Solar Cells for Higher Efficiency by Strain Control Based on In Situ Monitoring of MOVPE,” 2012 MRS Spring Meeting, G11.1, San Francisco, April 9-13 (2012).
  78. Shaojun Ma, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Gas Sequence Effect on In Situ Wafer Curvature Behavior in InGaAs/GaAsP Strain-Balanced MQWs,” 21st International Photovoltaic Science and Engineering Conference (PVSEC), 2D-4P-10, Fukuoka, November 28-Dececember 2 (2011).
  79. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Effects of Background Zn Doping on the Performance of MOVPE-Grown InGaAs/GaAsP Multiple Quantum Wells Solar Cells,” 21st International Photovoltaic Science and Engineering Conference (PVSEC), 4D-4P-05, Fukuoka, November 28-Dececember 2 (2011).
  80. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Impact of Strain Accumulation on InGaAs/GaAsP Multiple Quantum Wells Solar Cells: Direct Correlation Between In Situ Strain Measurement and Cell Performances,” 21st International Photovoltaic Science and Engineering Conference (PVSEC), 4D-4P-06, Fukuoka, November 28-Dececember 2 (2011).
  81. Masakazu Sugiyama, Yunpeng Wang, Hassanet Sodabanlu, Shaojun Ma, Hiromasa Fujii, Kentaroh Watanabe, and Yoshiaki Nakano, “Optical in situ monitoring of strain evolution and relaxation in lattice-mismatched InGaAs/GaAsP multiple quantum wells by MOVPE,” 15th U.S. Biennale Workshop on Organometallic Vapor Phase Epitaxy (OMVPE), Monterey, July 31-August 5 (2011).
  82. Shaojun Ma, Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Effect of hetero-interfaces on in situ wafer curvature behavior in InGaAs/GaAsP strain-balanced MQWs,” 15th U.S. Biennale Workshop on Organometallic Vapor Phase Epitaxy (OMVPE), Monterey, July 31-August 5 (2011).
  83. Yunpeng Wang, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “Management of highly-strained hetero interfaces in InGaAs/GaAsP strain-balanced superlattice for photovoltaic application,” 15th U.S. Biennale Workshop on Organometallic Vapor Phase Epitaxy (OMVPE), Monterey, July 31-August 5 (2011).
  84. Yunpeng Wang, Yu Wen, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “A Superlattice Solar Cell With Enhanced Short Circuit Current And Minimized Drop In Open Circuit Voltage,” 37th IEEE Photovoltaic Specialists Conference (PVSEC), p. 002674, Seattle, June 19-24 (2011).
  85. Shaojun Ma, Hassanet Sodabanlu, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano, “In-situ measurement and simulation of wafer curvature of InGaAs/GaAsP strain-compensated multiple quantum wells,” 38th International Symposium on Compound Semiconductors (ISCS), P1.10, Berlin, May 22-26 (2011).
  86. Hassanet Sodabanlu, Shaojun Ma, Kentaroh Watanabe, Masakazu Sugiyama, and Yoshiaki Nakano,“Structural evaluation of InGaAs/GaAsP multiple quantum wells via in-situ wafer's curvature measurement and ex-situ X-ray diffraction,” 2011 Compound Semiconductor Week (CSW) & 23rd International Conference on Indium Phosphide and Related Materials (IPRM), p. 4, Berlin, May 22-26 (2011).
  87. Hassanet Sodabanlu, Jung-Seung Yang, Takuo Tanemura, Masakazu Sugiyama, Yukihiro Shimogaki, and Yoshiaki Nakano, “Intersubband Absorption Saturation in GaN/AlN Multiple Quantum Wells Grown by Metalorganic Vapor Phase Epitaxy,” International Workshop on Nitride Semiconductors (IWN), C3.10, Tampa, September 19-24 (2010).
  88. Jung-Seung Yang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Intersubband absorption of 1.55 μm in AlN/GaN multi quantum wells grown at 770˚C by metal organic vapor phase epitaxy using pulse injection method,” 15th International Conference on Metal Organic Vapor Phase Epitaxy (ICMOVPE), p. 27, Incline Village, May 23-28 (2010).
  89. Michael Breedon, Hassanet Sodabanlu, Kourosh Kalantar-zadeh, Yoshiaki Nakano, and Masakazu Sugiyama, “Temperature dependant red shift of an intersubband transition in GaN/AlN multiple quantum wells,” 37th International Symposium on Compound Semiconductor (ISCS), FrP79, Takamatsu, May 31-June 4 (2010).
  90. Hassanet Sodabanlu, Jeong-Seung Yang, Masakazu Sugiyama, Yukihiro Shimogaki, Takuo Tanemura, and Yoshiaki Nakano, “Intersubband absorption saturation in AlN-based waveguide with GaN/AlN multiple quantum wells fabricated by metalorganic vapor phase epitaxy,” 15th European Conference on Integrated Optics (ECIO), WeP13, p. 1-2, Cambridge, April 6-9 (2010).
  91. Hassanet Sodabanlu, Jung-Seung Yang, Masakazu Sugiyama, Yukihiro Shimogaki, and Yoshiaki Nakano, “Improvement of 1.5-μm-range intersubband transitions in MOVPE grown GaN/AlN MQWs by AlGaN interlayer,” 8th International Conference on Nitride Semiconductors (ICNS), MP93, p. 279-280, Jeju, October 18-23 (2009).
  92. Jung-Seung Yang, Hassanet Sodabanlu, Masakazu Sugiyama, Yoshiaki Nakano, and Yukihiro Shimogaki, “Blue-shift of intersubband absorption wavelength by low temperature metal organic vapor phase epitaxy of AlN/GaN multi quantum wells by pulse injection method,” 8th International Conference on Nitride Semiconductors (ICNS), MP93, p. 764-765, Jeju, October 18-23 (2009).