Non-resonant below-bandgap two-photon absorption in quantum dot solar cells

作者：Li Tian; Dagenais Mario^*

来源：Applied Physics Letters, 2015, 106(17): 171101.

DOI：10.1063/1.4919381

We study the optically nonlinear sub-bandgap photocurrent generation facilitated by an extended tailing distribution of states in an InAs/GaAs quantum dots (QDs) solar cell. The tailing states function as both the energy states for low energy photon absorption and the photocarriers extraction pathway. One of the biggest advantages of our method is that it can clearly differentiate the photocurrent due to one-photon absorption (1PA) process and two-photon absorption (2PA) process. Both 1PA and 2PA photocurrent generation efficiency in an InAs/GaAs QD device operated at 1550 nm have been quantitatively evaluated. A two-photon absorption coefficient beta = 5.7 cm/GW is extracted.

• 出版日期2015-4-27