Efficient solar energy harvesting enabled by high-entropy ceramic nanofilms through a co-sputtering method

Recent advances in high-entropy ceramic nanofilms have unlocked new possibilities for preparing high-performance solar-thermal conversion materials. Due to their species diversity and structure distinctiveness, these materials provide huge room to exploit more appropriate compositions for boosting solar-thermal performance. Herein, we report a spectrally selective absorber based on high-entropy ZrNbMo-Cr-N ceramic nanofilm prepared by magnetron co-sputtering. Enabled by interface interference and intrinsic absorption effects, the as-deposited absorber exhibits a high solar absorptance of 96.3%, suppressed thermal emittance of 18.8%@400 ºС, and solar-thermal conversion efficiency of 85.4% under 400 ºС and 100 suns. Besides, due to the high configuration entropy of the absorption layers, the absorber exhibits superior thermal robustness after annealing at 400 ºС for 7 days. Further, the absorber can be well deposited on various substrates, including flexible cotton. Radiated by simulated sunlight, those absorber shows a good temperature response; in particular, the surface temperature of the absorber on cotton readily increases to 80 ºС with 50 s under 1 sun. Featured with those competitive merits, the high-entropy ceramic nanofilm absorber empowers a distinct paradigm to investigate solar-thermal conversion, rendering it attractive for various solar-thermal applications.