Efficient continuous-flow chemical bath deposition of CdS films as buffer layers for chalcogenide-based solar cells

Abstract

The highest power conversion efficiencies in copper indium gallium diselenide (CIGS) solar cells are achieved when a cadmium sulfide (CdS) buffer layer is deposited on the CIGS absorber through chemical bath deposition (CBD). These CdS buffer layers are also used in emerging kesterite solar cells such as those based on copper zinc tin sulfide/selenide. Herein, we describe a novel continuous-flow chemical bath deposition (CF-CBD) system for efficient utilization of chemicals during CdS film deposition. CdS films are grown on 10-cm-diameter molybdenum-coated silicon wafers to demonstrate the potential of the method to achieve uniform thin CdS films.