<p>Encapsulation films play a pivotal role in photovoltaic (PV) modules of solar panels. However, most commercial encapsulation films exhibit notably low thermal conductivity, which impedes heat dissipation, particularly during summer. consequently, heat accumulation within the modules reduces their power generation efficiency and shortens service life. Herein, a novel strategy is proposed to fabricate a composite encapsulation film that enhances heat conduction and thermal radiation capacity in PV modules. The composite film features high thermal conductivity (5.93&#xa0;W m^− 1 K^− 1), strong infrared emissivity (95.49%), enhanced solar reflectivity (90.25%), and excellent electrical insulation (2.35 × 10¹⁴ Ω·cm). Under direct summer sunlight, it enables an average temperature reduction of 4.1&#xa0;°C and a real-time operating voltage increase of 9.7 mV. Additionally, the maximum power output of the PV module is improved by 13.49% under one-sun irradiation of 1 kW m^− 2. Moreover, the composite film exhibits encapsulation performance on par with conventional encapsulants, without altering the existing mature structure and functionality of PV modules. Thus, this work provides a viable solution for solar energy deployment, especially in hot summer climates.</p> Graphical abstract <p></p>