Efficient Solar Energy Harvesting Enabled by High-Entropy Ceramic Nanofilms Through a Co-Sputtering Method

Abstract

Recent advances in high-entropy ceramic nanofilms have unlocked new possibilities to prepare high-performance solar-thermal conversion materials. However,  using such materials for solar-thermal materials has not received enough attention thus far. 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 design and prepare a novel spectrally selective absorber with high-entropy ceramic nanofilm by magnetron co-sputtering. Enabled by interface interference and intrinsic absorption effects, the as-deposited absorber exhibits decent solar absorptance of 96.3% and suppressed thermal emittance of 11%, leading to an impressive solar-thermal conversion efficiency (94.2%, 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 excellent temperature response; in particular, the surface temperature of the absorber on cotton readily increase 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.

Keywords: high-entropy ceramic nanofilm, solar-thermal conversion, spectrally selective absorber, thermal robustness, solar absorption