3 m m Intersubband Quantum Well Photodetector (QWIP)

Authors : Rita GUPTA, A L Y WONG, S K HAYWOOD

Pages : 673-680

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :In recent years photodetectors operating in the mid- to far infrared region of 3-15 m m have been designed based on electron and hole intersubband transitions in multiple quantum wells and superlattices. In general, QWIPs based on electron transitions show greater detectivity compared to the hole-based photodetectors. However, selection rules for electron intersubband transitions usually forbid the TE mode operation, associated with normal light incidence; Therefore, special coupling structures/geometries have been employed to couple light into the device. The spectral region 3-5 m m is of interest for a variety of applications such as environmental gas sensing, thermal imaging etc. and is not well covered by existing detectors. We have grown a QWIP operating at \sim 3m m with a normal incidence component which incorporates an InGaAs/GaAs asymmetric quantum well from which photo-excited carriers undergo resonant tunnelling into the AlGaAs barriers. A study of temperature-dependent dark current of this device is presented with a view to obtaining enhanced detectivity at high temperatures.
Keywords : Turk J Phys, 23, 1999, 673 680 Turk J Phys, vol 23, iss 4