Characteristics of thermally treated quantum-dot infrared photodetector

Abstract

We investigated the device performances for a post-growth thermally. treated In(0.5)Ga(0.5)As/GaAs quantum-dot infrared detector (QDIP). Device characteristics, such as dark current, photoluminescence (PL), and photocurrent spectra, have been studied and compared for the as-grown and thermally treated QDIPs. After the thermal treatment with a SiO(2) capping layer, the dark current was increased, the PL peak position was blue-shifted, and the detection wavelength was redshifted due to In/Ga interdiffusion in the quantum dot (QD) structure. Furthermore, the activation energies estimated from the integrated PL intensities agreed well with the peak positions of the photocurrent spectra.