[14a-2M-1~11] 13.10 Compound solar cells

△ [14a-2M-11] Design Optimization for Two-Step Photon Absorption by Infrared Photocurrent Spectroscopy

〇Ryo Tamaki¹, Yasushi Shoji¹, Yoshitaka Okada¹ (1.RCAST, The Univ. of Tokyo)

Keywords:quantum dot solar cell,intermediate band solar cell,two-step photon absorption

We have investigated infrared photocurrent spectra of two-step photon absorption in multi-stacked quantum dot solar cells by utilizing Fourier transform infrared spectroscopy. The band offset between In(Ga)As quantum dot ground state and conduction band in the barrier layer was systematically controlled by varying the barrier layer's material. In the second step infrared photocurrent spectra, the absorption edge energy and the threshold temperature indicated linear relationship. This result clarified the optimized design of photo-carrier confinement for high efficiency room temperature operation.