Strain Layer Quantum Well Infrared Photodetectors(invited)

Abstract

We present a study of several n- and p-type strain-layer quantum well infrared photodetectors (SL-QWIPs) using InxGa1-xAs/ALGa1-yAs grown on GaAs and InxGa1-xAs/InyAl1-yAs on InP substrates. The results show a significant improvement in device performance for these devices over the unstrained QWIPs. The devices studied include a high-strain (HS-) n-type InGaAs/AlGaAs/InGaAs triple-coupled (TC-) QWIP, a HS-n-type InGaAs/AlGaAs QWIP, a compressively strained layer (CSL-) p-type InGaAs/AlGaAs QWIP, and a tensile-strained layer (TSL-) p-type InGaAs/InAlAs QWIP. In addition to the improvement in performance, a large normal incidence absorption has also been observed in both the HS- n-type QWIP and TC-QWIP. The device physics and performance parameters such as the optical absorption coefficient, dark current, spectral responsivity, and detectivity for these SL-QWIPs are depicted in this paper.