Development of quantum well infrared photodetectors at the Center for Quantum Devices

Results of detector characterization are presented for quantum well infrared photodetectors (QWIPs) fabricated from a variety of III-V material systems lattice-matched to GaAs or InP substrate, p-Type GaAs/GaInP QWIPs show background limited performance up to temperatures of 120 K, while p-type GaInAsP/GaInAsP QWIPs exhibit broadband response from lambda = 2.5-10 mum. n-Type GaAs/GaInP QWIPs are sensitive deep into the VLWIR with very low dark current. Extremely large responsivities of 33.2 AW(-1) were obtained from n-type GaInAs/InP QWIPs operating at lambda = 9 mum. Devices made from n-type AlGaInAs/InP and GaInAs/AlInAs have also been realized that extend the wavelength range of sensitivity from 3 mum out to 20 mum while remaining lattice-matched to InP. Lattice-matched multispectral detectors are demonstrated for sensitivity at both 4 and 8.5 mum Localized epitaxy of GaInAs/InP superlattice structures lattice-matched to InP was performed on Si substrate for the purpose of monolithic integration of III-V QWIPs with Si-based read-out integrated circuitry. (C) 2001 Elsevier Science B.V. All rights reserved.