CdTe thin-film solar cells are already cost-competitive for generating electricity in many parts of the world. One way to further improve device efficiency and decrease electricity costs is to improve the front contacts. The standard window layer material, CdS, parasitically absorbs over 20% of incident light. These losses can largely be eliminated by reducing the thickness of this layer or replacing it with a higher-bandgap material. We have demonstrated this in three ways: using a high-resistance transparent layer, oxygenated cadmium sulfide, and most recently (Mg,Zn)O, which has allowed an increase in efficiency from approximately 13% to over 18% and offers a variety of advantages over CdS in processing of advanced devices.
Post time: Feb-15-2017