Slot-Die Coated Copper Indium Disulfide as Hole-Transport Material for Perovskite Solar Cells

Abstract

Perovskite photovoltaics have the potential to significantly lower the cost of producing solar energy. However, this depends on the ability of the perovskite thin film and other layers in the solar cell to be deposited using large-scale techniques such as slot-die coating without sacrificing efficiency. In perovskite solar cells (PSCs), Spiro-OMeTAD, a small molecule-based organic semiconductor, is commonly used as the benchmark hole transport material (HTL). Despite its effective performance, the multi-step synthesis of Spiro-OMeTAD is complex and expensive, making large-scale printing difficult. Copper indium disulfide (CIS) was chosen in this study as an alternative inorganic HTL for perovskite solar cells due to its ease of fabrication, cost-effectiveness, and improvements to the economic feasibility of cell production. In this study, all layers of perovskite solar cell were printed and compared to a spin-coating-based device. Various parameters affecting the layer quality and thickness were then analyzed, including substrate temperature, print head temperature, printing speed, meniscus height, shim thickness, and ink injection flow rate. The small print area achieved spin-coating quality, which bodes well for large-scale printing. The printed cell efficiencies were comparable to the reference cell, having a 9.9% and 11.36% efficiency, respectively.