Improve the Photoelectric Properties of Transparent Insulating Films Through Simple Mechanical Pressure Treatment

ABSTRACT In this study, a transparent insulating film that possesses high visible light transmittance, high resistivity, and excellent resistance to potential‐induced degradation (PID) is developed via a simple and innovative physical modification technique. By employing mechanical pressure treatment (MPT), the internal porosity of the ethylene vinyl acetate copolymer (EVA) film is decreased. This results in a 0.5% increase in average transmittance and a theoretically calculated enhancement in photovoltaic (PV) cell efficiency of over 0.1%. Additionally, the pores of the EVA film become denser, effectively suppressing leakage current carriers induced by structural defects. As a result, the volume resistivity of the EVA film is significantly improved, with increments of 36% and 48% at room temperature and 60°C, respectively. Compared to conventional chemical modification approaches, this MPT technique significantly improves the defects of the film during the film‐forming process without altering its structure or negatively affecting the properties of the packaging material. This method also demonstrates a reduction in the migration of Na + from the PV module glass to the cell, thereby improving the performance of the module. When integrated with light‐induced recovery (LIR) encapsulation protocols, the optimized EVA film represents a promising and cost‐effective solution for mitigating PID in commercial PV systems. This advancement provides critical insights into defect engineering for polymeric encapsulants while offering industrially scalable processing advantages.