Accelerated development of CuSbS2 thin film photovoltaic device prototypes

摘要

Development of alternative thin film photovoltaic technologies is animportant research topic due to the potential for low-cost, large-scalefabrication of high-efficiency solar cells. Despite the large number ofpromising alternative absorbers and corresponding contacts, the rate ofprogress is limited by complications that arise during solar cell fabrication.One potential solution to this problem is the high-throughput combinatorialmethod, which has been extensively used for research and development ofindividual absorber and contact materials. Here, we demonstrate an acceleratedapproach to development of thin film photovoltaic device prototypes based onthe novel CuSbS2 absorber, using the device architecture employed forCuInxGa(1-x)Se2 (CIGS). The newly developed three-stage, self-regulated CuSbS2growth process enables the study of PV device performance trends as a functionof phase purity, crystallographic orientation, layer thickness of the absorber,and numerous back contacts. This exploration results in initial CuSbS2 deviceprototypes with ~1% conversion efficiency; currently limited by lowshort-circuit current due to poor collection of photoexcited electrons, and asmall open-circuit voltage due to a cliff-type conduction band offset at theCuSbS2/CdS interface (suggested by first-principles calculations). Overall,these results illustrate the potential of combinatorial methods to acceleratethe development of thin film photovoltaic devices with novel absorbers.