Design and simulation of bias-selectable few photon dual-colour photodetector operating in visible and nearinfrared regions

摘要

In this paper,we report the design and simulation of a bias-selectable dual-band photodetector operating in the visible(VIS)and near infrared(NIR)regions.The photodetector consists of two back-to-back avalanche photodiodes(APDs)with InGaAs and Si absorption layers respectively.The structure and electrical and optical properties of the dual-color photodetector were designed and simulated by exploiting Silvaco software.The results obtained on the basis of numerical simulation include the current-voltage,capacitance-voltage,spectral response,etc.The optical simulation shows the detection capability in the VIS and NIR ranges,cut-off wavelengths of 1.0μm and 1.8μm depending on the applied bias polarity.Comparing with using the PIN structure as element device,the dual-band photodetector based on the APD configuration could detect the very weak signal,realizing few photons,even single photon detection.