Properties of In 0.5 Ga 0.5 As/GaAs/ Al 0.2 Ga 0.8 As quantum-dots-in-a-well infrared photodetectors

Abstract

We report on an experimental and theoretical study of the optical and dark current properties of In0.5Ga0.5As/GaAs/Al 0.2Ga0.8As quantum-dots-in-a-well infrared photodetectors. In particular, we investigate the spectral tunability of the dot-to-well transitions by quantum well thickness variations. The effects of the quantum well states on the dark current characteristics are also investigated. Modelling of the electron thermal energy distribution suggests the large density of states in the quantum well can lead to a lowering of the dark current activation energy. Show more