Intraband relaxation of photoexcited carriers in multiple stacked quantum dots and quantum dot chains

We report on the intraband relaxation properties of photoexcited carriers in ordinary stacked quantum dots (QDs) as well as QD chains in which QDs are interconnected along the growth direction. We found that the effect of lateral coupling on the intraband relaxation process in the stacked QD sample is less than that in the QD chain sample. This affection depends on the exciton lifetime. However, by comparison with our previous report, it is deduced that the exciton transfer is not so fast process. Therefore, we consider that it is possible to extract the carriers generated by visible light before the diffusion occurring in the in-plane direction.