GAAS ALGAAS QUANTUM-WELL INFRARED PHOTODETECTORS ON GAAS-ON-SI SUBSTRATES/

In this letter, we describe the characteristics of molecular beam epit axy GaAs/AlGaAs quantum-well infrared photodetectors (QWIP's) grown on a GaAs substrate, and on a GaAs-on-Si substrate produced by metalorga nic chemical-vapor deposition. Important issues for QWIP applications such as dark current, spectral response, and absolute responsivity are studied. We find that compared to a similar detector structure grown on a GaAs substrate, the detector grown on a GaAs-on-Si substrate exhi bits similar dark current and absolute responsivity while displaying a small blueshift in the spectral response. (C) 1997 American Institute of Physics.