Properties of Electro-Deposited CuSCN Thin Films with Different Electrodeposition Charge Density

Abstract

The development of efficient CuSCN hole transport layers is crucially important for achieving high photovoltaic performance in inorganic perovskite devices. In this study, the effects of electrodeposition charge density on the morphological/microstructural and electrical properties and the formation mechanism of electro-deposited CuSCN films are investigated and discussed. The results indicate that the charge density is the key factor that governs not only the thickness, but also morphological, electrical, and surface properties of the electro-deposited CuSCN films. For the energy band diagram property, we found that when the charge density is 120 mC cm−2 (named as CD120), the valance band of CuSCN near ITO work function. This excellent property can efficiently improve the photovoltaic performance of inorganic perovskite devices, where ITO and CuSCN are employed, owing to the reduction of energy barrier. Among the films electro-deposited at different charge densities, the CD120 exhibits the highest mobility, possibly due to the excess amount of SCN in the thin film.