Optimizing anti-reflection coating using electrochemical impedance spectroscopy to enhance electrical performance of solar cell
摘要
Increasing the efficiency of bifacial passivated emitter and rear contact (PERC) solar cells is crucial for meeting industrial-scale demand for economical and high-performance photovoltaic systems. Anti-reflection coatings (ARCs) play a key role by minimizing reflection losses, maximizing light absorption, and enhancing surface passivation. Precise control over ARC thickness is essential to achieve optimal performance. In this study, the optimum thickness of silicon nitride ARC on bifacial PERC solar cells was investigated using optical measurements and electrochemical impedance spectroscopy (EIS) characterization. Thicknesses ranging from 70 to 100 nm were deposited on various PERC solar cells via plasma-enhanced chemical vapour deposition (PECVD) in an industrial facility. Among the tested ARCs, an 85 nm coating exhibited the lowest reflectance of 1.30% across the 400–1000 nm wavelength range, yielding a superior power conversion efficiency of 23.61 ± 0.20% under standard test conditions (AM1.5G, 1000 Wm−2, 25 °C). EIS analysis further elucidated the electrochemical characteristics, revealing that the resistive and capacitive values of the device were optimum at an ARC thickness of 85 nm. The enhanced electrical performance was attributed not only to improved optical properties but also to reduced bulk and surface recombination rates, facilitated by better surface passivation. By integrating optical measurements and EIS analysis, this study provides a comprehensive approach to optimizing ARC for efficient bifacial PERC solar cells, addressing both optical and electrical parameters for industrial applications.