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

• Published in: Journal of alloys and compounds Vol. 934; p. 167899
• Main Authors: He, Cheng-Yu, Zhao, Peng, Gao, Xiang-Hu, Liu, Gang, La, Pei-Qing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.02.2023
• Subjects: High-entropy ceramic nanofilm; Solar absorption; Solar-thermal conversion; Spectrally selective absorber; Thermal robustness; Solar-thermal conversion; High-entropy ceramic nanofilm; Spectrally selective absorber; Solar absorption; Thermal robustness
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.167899

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. •The well-designed ZrNbMo-Cr-N HECN SSA embraces a high solar absorptance of 96.3% and low thermal emittance of 18.8%@400 ºС as well as a direction-independent absorption.•The ZrNbMo-Cr-N SSA shows superior thermal robustness, no significant optical performance attenuation is observed even after annealing at 800 °C for 2 h, which is capable of diverse temperature solar-thermal applications.•FDTD simulation proves that the collective effects of destructive interference and intrinsic absorption of ZrNbMo-Cr-N HECN boost sunlight harvesting ability.•Upon 1.5 sun (1.5 kW m−2) irradiation, the high surface temperature of more than 100 °C is captured, suggesting great potential in solar interface evaporation-related applications.