Photoconductivity peculiarities in InGaAs quantum wire heterostructures: anisotropy and high photoresponsivity at room temperature

摘要

The anisotropy of photoconductivity was measured in InGaAs/GaAs quantum wire heterostructures. This anisotropy is the result of a one-dimensional band creating an effective channel for photo-generated carriers. High photoresponsivity of ～ 2.3 A W~(-1) at 0.3 μW cm~(-2) incident light excitation was revealed at the InGaAs band edge absorption at room temperature. We show that the observation of this high photoresponsivity at lower power densities is due to the presence of both local electric fields at the InGaAs/GaAs interface caused by structural non-uniformities and a trap at ～ 68 meV below the GaAs conductivity band edge. A proposed lateral one-dimensional photoconductive heterosystem is a good candidate for high sensitivity, low-bias infrared detectors.