Enhanced Radiative Cooling Performance in P(VDF‐TrFE) Copolymer Based on Phononic Properties

Abstract Passive radiative cooling technology is realized by increasing solar reflection and infrared emission. Polymer materials demonstrate greater potential in multi‐scenario cooling applications due to their excellent flexibility and manufacturability. Intrinsic characteristic modification is crucial for enhancing the performance of materials. Here, the radiative cooling properties of PVDF and P(VDF‐TrFE) with different C─F content are evaluated. Theoretical studies based on first‐principles calculations are conducted to understand the screening of chemical bonds from phonon dispersions. Then the optical performances are tested, with P(VDF‐TrFE) showing an enhanced net cooling power of 41% and 21% during daytime and nighttime, respectively. On‐site measurements have also been conducted. Compared to PVDF, the average cooling temperature drops of P(VDF‐TrFE) increase from 7.2 to 8.5 °C at noon and from 2.1 to 3.5 °C at night. This work successfully bridges atomic‐scale characteristics with material‐level radiative performance, providing a reference for finding effective radiative cooling materials through phononic properties.