Investigation of optical, dielectric, and electrical properties of ZnO/cold sprayed Al system and their correlation with photovoltaic performance

Abstract

This study explores the optical, dielectric, and electrical properties of ZnO layers deposited on cold sprayed Al layer, emphasizing their potential for optoelectronic and photovoltaic applications. Optical measurements revealed a reduction in the ZnO bandgap to approximately 2.45 eV when interfaced with Al, broadening its absorption into the visible range and enhancing light-harvesting capabilities. Dielectric analysis showed a significant increase in the real part of the dielectric constant (ε_r), reaching values up to 2.8 in the visible spectrum, indicative of polarization behavior. The imaginary part (ε_i) demonstrated enhanced light absorption, further supported by increased optical conductivity (σ_opt). Electrical conductivity analysis revealed improved charge transport properties, highlighting the ZnO/Al system’s efficiency in facilitating charge transfer. To evaluate its photovoltaic potential, the ZnO/Al system was integrated into a simulated perovskite solar cell as the electron transport layer (ETL). The simulated device achieved a power conversion efficiency (PCE) of 27.1%, with Jsc = 28.2 mA/cm², Voc = 1.2 V, and FF = 82%. Optimization of the ZnO thickness revealed that a 100 nm layer would provide the best performance, balancing light absorption, charge transport, and minimal resistance. The external quantum efficiency (EQE) spectrum demonstrated a peak response (~ 90%) in the visible range (400–750 nm), confirming the efficiency of charge collection and transport. These findings highlight the superior optical, dielectric, and electrical properties of the ZnO/Al system, making it a promising candidate for high-efficiency optoelectronic and photovoltaic devices. The results provide a solid foundation for further development of ZnO-based materials in renewable energy applications.