Improved Spectral Response of Quantum Dot Solar Cells Using InAs Multi-stack High Density Quantum Dot Molecules

Abstract

In this paper, we report the spectral response measurement of Schottky solar cells with conventional quantum dots (QDs) and high-density quantum dot molecules (HD-QDMs) as active layers. 3-stack HD-QDMs Schottky structure is compared to 15-stack QD Schottky structure and control sample without QDs. 15-stack conventional InAs QDs give narrow response peak centered at 907 nm while 3-stack InAs HD-QDMs give broad peak between 915 and 985 nm. Both spectral responses are extended beyond the band edge of GaAs, i.e. 870 nm. 42 % more photovoltaic power could be evident from the extended spectral response curve comparing to that of GaAs bulk sample without dots.