Researchers have investigated the properties of nickel oxide (NiO) thin films deposited on flexible indium tin oxide (ITO) and polyethylene terephthalate (PET) substrates. This study focuses on how the thickness of the NiO layer influences its structural, optical, and electrical characteristics, aiming to optimize its performance in flexible solar cell applications. The ability to control these properties is crucial for the development of next-generation photovoltaic devices, which require transparent, conductive, and mechanically robust materials.

Nickel oxide is a p-type semiconductor with a wide bandgap, making it suitable for use as a hole transport layer in solar cells, particularly in perovskite or quantum dot architectures. The flexibility of ITO/PET substrates enables the fabrication of lightweight and conformable devices, opening doors for applications such as wearable electronics or architectural integration. The systematic investigation of thickness dependence is fundamental to understanding growth mechanisms and interface interactions, which dictate the final device efficiency.

Preliminary results suggest that the optical and electrical properties of NiO layers can be precisely tuned by varying their thickness. Changes were observed in transmittance, resistivity, and charge carrier mobility, indicating optimizable behavior to maximize light harvesting and current extraction in a solar cell. These findings represent a significant step towards engineering interfaces and active layers in flexible photovoltaic devices, where stability and efficiency are key parameters for improvement.