Accelerated development of CuSbS₂ thin film photovoltaic device prototypes

Abstract

Development of alternative thin film photovoltaic technologies is an important research topic due to the potential for low-cost, large-scale fabrication of high-efficiency solar cells. Despite the large number of promising alternative absorbers and corresponding contacts, the rate of progress is limited by complications that arise during solar cell fabrication. One potential solution to this problem is the high-throughput combinatorial method, which has been extensively used for research and development of individual absorber and contact materials. Here, we demonstrate an accelerated approach to development of thin film photovoltaic device prototypes based on the novel CuSbS 2 absorber, using the device architecture employed for CuIn x Ga (1-x) Se 2 (CIGS). The newly developed three-stage, self-regulated CuSbS 2 growth process enables the study of PV device performance trends as a function of phase purity, crystallographic orientation, layer thickness of the absorber, and numerous back contacts. This exploration results in initial CuSbS 2 device prototypes with ~1% conversion efficiency, currently limited by low short-circuit current due to poor collection of photoexcited electrons, and a small open-circuit voltage due to a theoretically predicted, cliff-type conduction band offset between CuSbS 2 and CdS. Overall, these results illustrate the potential of combinatorial methods to accelerate the development of thin film photovoltaic devices with this and other novel absorbers.

Selection Metric for Photovoltaic Materials Screening Based on Detailed-Balance Analysis

“…This is not particularly surprising given that our selection of materials generally exhibit quite good optical properties for photovoltaic applications. The current lack of success of materials such as CZTSe [75], CuSbS 2 [76,77] or CuSbSe 2 [78] is a matter of being lower than for Cu(In,Ga)Se 2 . Thus, there is a need for computational materials screening to focus on parameters that are related to the presence of defects such as the search for defect-tolerant materials.…”

Two-stage co-evaporated CuSbS2 thin films for solar cells

“…Ikeda et al fabricated the solar cells by electro-deposition with efficiency of 3.13% and open-circuit voltage (V oc ) of 490 mV, which is the best record in CuSbS 2 solar cells up to now [9]. Welch et al fabricated the solar cells by magnetron sputtering with an efficiency of 0.86% and V oc of 309 mV [20]. Yang et al fabricated the solar cells by spin coating with an efficiency of 0.5% and V oc of 440 mV [11].…”

A Two-Step Absorber Deposition Approach To Overcome Shunt Losses in Thin-Film Solar Cells: Using Tin Sulfide as a Proof-of-Concept Material System

“…Device shunting due to pinhole formation has been observed in other polycrystalline thin-film materials as well. Novel polycrystalline absorber materials such as antimony selenide (Sb 2 Se 3 ) 17 and copper antimony sulfide (CuSbS 2 ) 18 have been successfully applied in photovoltaic devices. However, low shunt resistances have been reported which may limit the device performance todate.…”