Light Soaking and Gas Effect on Nanocrystalline TiO₂/Sb₂S₃/CuSCN Photovoltaic Cells following Extremely Thin Absorber Concept

Abstract

Photovoltaic cells with the structure of nanocrystalline TiO2/Sb2S3/(LiSCN)CuSCN were prepared following the extremely thin absorber cell concept and characterized under different gas atmospheres. The cells showed an important light soaking effect in which the cell performance typically evolved from an initial lower efficiency into a higher one in contact with ambient air. Oxygen was shown to be involved with the effect. The best cell efficiency was 3.7% at ∼1 sun, with a photocurrent Jsc normalized at 1 sun of 11.6 mA/cm2, an open-circuit voltage Voc of 0.56 V, and a filling factor, ff, of 0.58. The cells are shown to run more than 300 days, keeping the efficiency higher than 1.5% at ∼1 sun. The need for taking into account the influence of oxygen and humidity during photovoltaic measurement is emphasized for further investigation of this type of cell.