■ Example of research topics ■
Direct observation of carrier transport dynamics in quantum structures using time-of-flight technique
K. Toprasertpong, M. Asami, A. Delamarre, K. Watanabe, Y. Nakano, and M. Sugiyama
Quantum structures such as quantum wells or quantum wires are promising materials to realize next-generation solar cells, including the applications in multi-junction solar cells, intermediate-band solar cells, and hot-carrier solar cells. To fully extract their potential, we have to gain our understanding of the carrier transport dynamics inside such structures. Carrier transport dynamics so far has been analyzed using indirect measurement methods which have a limitation in understanding the underlying physics. We introduce the “carrier time-of-flight” measurement technique which can directly observe the carrier dynamics including the transport time and velocity inside the quantum structures. This allows us to analyze the carrier transport in the microscopic scale and provides important clues for the theoretical modeling of effective carrier mobility and related phenomena in the quantum structures.
Fig. Carrier time-of-flight measurement technique and example of measurement results.