Modelling of photoresponse components induced by laser pulse across a p-n junction

Abstract

The photoresponse signal induced by 1.06 m laser pulse across a Gals p-n junction is shown to be composed of three pronounced components resulting from hot carrier, heating lattice, and two-photon absorption phenomena. The first one is fast and has polarity of thermoelectromotive force of hot carriers. The second one has the same polarity, is slower, and is caused by the junction heating. The third one, respectively, is the classical electron-hole pair generation-induced photovoltage with polarity opposite to that of the first two. Good agreement between experimental and calculated results is achieved. The proposed model enables revealing contribution of each component to the net magnitude of the photoresponse, and can open the way in reducing negative impact of hot carriers into photovoltage of a solar cell.