Anomalous Capacitance–Voltage Characteristics of GaAs/AlGaAs Multiple Quantum Well Solar Cells

Abstract

We study the capacitance–voltage characteristics of GaAs/AlGaAs coupled multiple quantum well (MQW) solar cells. It is found that the capacitance under illumination increases sharply if the bias is raised above -0.2 V, and gets maximum at a bias of about 0.2 V. This increment in capacitance by the illumination is ascribed to the reduction of the depletion layer thickness, caused by the spatially separated accumulation of photogenerated electrons and holes trapped in the MQW layer.