GROWTH AND CHARACTERIZATION OF N-TYPE GAAS ALGAAS QUANTUM-WELL INFRARED PHOTODETECTOR ON GAAS-ON-SI SUBSTRATE/

We present in this article device characteristics of molecular beam ep itaxy grown GaAs/AlGaAs quantum well infrared photodetectors (QWIP) on a semiinsulating GaAs substrate and on a GaAs-on-Si substrate grown b y metalorganic chemical vapor deposition (MOCVD). Important issues for QWIP application such as dark current, spectral response, and absolut e responsivity were measured. We find that the detector structure grow n on a GaAs-on-Si substrate exhibits comparable dark current and absol ute responsivity and a small blue shift, in the spectral response. Thi s is the first demonstration of long wavelength GaAs/AlGaAs quantum we ll infrared photodetector using MOCVD grown GaAs-on-Si substrate and t he performance is comparable to a similar detector structure grown on a GaAs substrate.