Detection wavelength and device performance tuning of InAs QDIPs with thin AlGaAs layers

Abstract

QDIPs with thin inserted AlGaAs layers adjacent to the QDs were investigated for the tailoring of detection wavelength and device performance. Simple InAs/GaAs QDIPs and DWELL QDIPs with different insertion layer structure were studied. The thin AlGaAs layer is shown to effectively modify the electron wavefunction and associated confined state energies which lead to the change of the detection wavelength and the polarization dependent quantum efficiency. Furthermore. the dark current and gain also change with different device structures. The insertion of AlGaAs layers provides an additional freedom of tuning the electronics states involved in the infrared detection and also enables the improvement of the absorption and device performance. (C) 2009 Elsevier B.V. All rights reserved.