Improving the performance of Sb2 Se3 thin film solar cells over 4% by controlled addition of oxygen during film deposition

Sb2Se3 has attracted great research interest very recently as a promising absorber material for thin film photovoltaics due to its suitable bandgap, high absorption coefficient, and non-toxic, low cost, and earth abundant nature. In this work, a significant efficiency improvement to 4.8% of superstrate cadmium sulfide (CdS)/Sb2Se3 solar cells is obtained by the controlled addition of oxygen during thermal evaporation of Sb2Se3 films. Systematic materials and device physics characterization reveal that oxygen addition during Sb2Se3 film evaporation significantly improves the CdS/Sb2Se3 heterojunction quality through effective passivation of interfacial defect states, resulting in a substantial enhancement in device circuit voltage and short circuit current density. The 4.8% device is the highest efficiency thus far reported for Sb2Se3 thin film solar cells. Copyright © 2015 John Wiley & Sons, Ltd.