Comparison of MBT and BTQB Quantum Well Infrared Photodetectors and Implications for Multicolor Design

Abstract : A comparison is presented between two GaAs/AlGaAs quantum well infrared photodetector (QWIP) designs: the miniband transport (MBT) and the bound-to-quasibound (BTQB). Two QWIP test arrays were prepared, designed to have the same peak operating wavelength, doping density, barrier thickness, and excited state binding energy. The detectors are long wavelength infrared (LWIR), each having about a 9.1-microns-peak wavelength. The detector array test structures used edge coupling to remove the grating or optical coupling structure effects from the detector response characteristics. Extensive bias and spectral-dependent blackbody response and specific detectivity data will be presented. The data show that MBT and BTQB QWIPs offer comparable performance.