Origin of photocurrent in lateral quantum dots-in-a-well infrared photodetectors

Abstract

Interband and intersubband transitions of lateral InAs In0.15 Ga0.85 As dots-in-a-well quantum dot infrared photodetectors were studied in order to determine the origin of the photocurrent. The main intersubband transition contributing to the photocurrent (PC) was associated with the quantum dot ground state to the quantum well excited state transition. By a comparison between intersubband PC measurements and the energy level scheme of the structure, as deduced from Fourier transform photoluminescence (FTPL) and FTPL excitation spectroscopies, the main transition contributing to the PC was identified. © 2006 American Institute of Physics.