Abstract NiCr–MgF2 spectrally selective solar absorber, which consists of the tandem films of Au, high-metal-volume-fraction (HMVF) NiCr–MgF2, low-metal-volume-fraction (LMVF) NiCr–MgF2 and MgF2, is designed and fabricated for ultra-high solar absorptance and low thermal emittance. The performance of Au/NiCr–MgF2 (HMVF)/NiCr–MgF2 (LMVF)/MgF2 is simulated using the effective medium theory and film matrix method, and the optimized NiCr–MgF2 spectrally selective solar absorber has a normal solar absorptance (αsn) of 0.981 and a normal thermal emittance (en) of 0.042 at 25 °C. The tandem films of Au/NiCr–MgF2 (HMVF)/NiCr–MgF2(LMVF)/MgF2 are fabricated by magnetron sputtering and measured by UV-VIS-IR spectrometer, and it has an ultra-high near normal solar absorptance of αsn = 0.976 and a low near normal thermal emittance of en = 0.045 at 25 °C, which approaches very closely to the simulated limit. Furthermore, NiCr–MgF2 spectrally selective solar absorber allows a wide incident angle (θ) with its angular solar absorptance αs(θ)≥0.957 and angular thermal emittance e(θ)≤0.054 if θ ≤ 50°. Such spectrally selective solar absorber is an outstanding candidate for solar thermal applications.

中文翻译：

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NiCr-MgF2 具有超高太阳能吸收率和低热辐射率的光谱选择性太阳能吸收剂

摘要 NiCr-MgF2 光谱选择性太阳能吸收器由 Au、高金属体积分数 (HMVF) NiCr-MgF2、低金属体积分数 (LMVF) NiCr-MgF2 和 MgF2 的串联薄膜组成。并为超高太阳能吸收率和低热辐射率而制造。Au/NiCr-MgF2 (HMVF)/NiCr-MgF2 (LMVF)/MgF2 的性能使用有效介质理论和薄膜矩阵方法进行模拟，优化后的 NiCr-MgF2 光谱选择性太阳能吸收器具有正常的太阳能吸收率 (αsn) 0.981 和 25 °C 时的正常热发射率 (en) 为 0.042。Au/NiCr-MgF2 (HMVF)/NiCr-MgF2(LMVF)/MgF2 串联薄膜是通过磁控溅射制备的，并通过 UV-VIS-IR 光谱仪测量，它具有超高的接近正常的太阳吸收率 αsn = 0.976 和在 25 °C 时接近正常的低热发射率 en = 0.045，非常接近模拟极限。此外，NiCr-MgF2 光谱选择性太阳能吸收器允许宽入射角 (θ)，其角太阳能吸收率 αs(θ)≥0.957，角热发射率 e(θ)≤0.054，如果 θ ≤ 50°。这种光谱选择性太阳能吸收器是太阳能热应用的杰出候选者。