Investigation of structural, optical and electrical properties of Zn doped CuO thin films prepared by chemical bath deposition

Abstract Perovskite solar cells (PSCs) have rapidly emerged as promising next-generation photovoltaic technologies due to their remarkable power conversion efficiencies and low fabrication costs. The performance of PSCs strongly depends on the properties of their functional constituent layers, particularly the hole transport layer (HTL) plays a vital role in controlling and ensuring efficient charge extraction and overall device efficiency and stability. In the present study, Zn-doped copper oxide (CuO) thin films with a monoclinic structure were synthesized via a simple and low-cost chemical bath deposition (CBD) techniques on glass substrates to explore their suitability as HTL materials. The influence of zinc doping concentration on the structural, optical, and electrical properties of the films was systematically investigated using X-ray diffraction (XRD), Raman spectroscopy, UV-Vis spectroscopy, and the hot probe technique. Obtained results revealed that increasing Zn concentration affected the crystallinity and maintained p-type conductivity, with optical bandgaps ranging between 1.40 and 1.50 eV. These optimized and tunable physical properties highlight the potential of Zn-doped CuO thin films as efficient, stable, and low-cost materials for HTLs in perovskite solar cells, offering a cost-effective pathway toward high-performance and durable photovoltaic devices.