Multiple quantum well GaAs/AlGaAs solar cells: transport and recombination properties by means of EBIC and cathodoluminescence

Multiple quantum well (MQW) p-i-n heterostructures are a new alternative to increase the quantum efficiency of solar cell devices. In such structures, the QW carrier capture, carrier escape and radiative recombinations are the phenomena governing the efficiency of the p-i(MQW)-n solar cell. In this contribution, in spite of the photon-induced current mode of work of such device, an electron beam-induced-current (EBIC) study allowing a very localized carrier excitation is reported. The EBIC measurements are shown to be able to estimate with high accuracy the QWs capture–escape and radiative lifetimes. The latter are determined as a function of the carrier injection level fitting experimental EBIC profiles to simulated ones. Values around 10−10 and 10−7 s respectively are obtained.