## 4 Commercial Configurations of STSCs  
Many STSCs have been developed, but few have been successfully commercialized. Various companies worldwide commercially fabricated STSCs such as SS-AlN, SS-C, CrN-CrxOy, PTR(r)70 Premium, Mo-SiO\({}_{2}\), and TiNO\({}_{\mathsf{X}}\)/Cu. Table 3 demonstrates the commercially available sputter-deposited coatings for mid-temperature applications. Commercially available solar selective coatings are primarily used in solar thermal applications, where they enhance the efficiency of solar energy conversion by selectively absorbing sunlight while minimizing heat loss. These coatings are applied to surfaces in solar collectors, such as those used in water heating systems, solar power plants, and industrial processes,  
\begin{table}
\begin{tabular}{l l l l l l l} \hline \hline
**Ref.** & **Year** & **STSC Composition** & **Substrate** & \(\alpha_{\mathsf{s}}\) (\%) & \(\varepsilon_{\mathsf{th}}\) (\%) & **T (°C)** & **n (\%)** \\ \hline
[80] & 2002 & W & Bulk-W & 92 & 7.5 & 527 & - \\ \hline
[75] & 2012 & CuCr\({}_{2}\)O\({}_{4}\) spinel powder & SS & 91 & 6.0 & 600 & - \\ \hline
[78] & 2012 & TiAlN/TiAlON/Si\({}_{3}\)N\({}_{4}\) & SS & 96 & 17 & 450 & - \\ \hline
[95] & 2012 & HfMoN(H)/HfMoN(L)/HfON/Al\({}_{2}\)O\({}_{3}\) & SS & 94.1 & 14 & 82 & 86 \\ \hline
[77] & 2014 & Pyromark 250 & SS & 96 & 8.0 & 600 & - \\ \hline
[96] & 2014 & Ta/Al\({}_{2}\)O\({}_{3}\)/Pt/Al\({}_{2}\)O\({}_{3}\) & Ta/Cu & 93.2 & 10 & 82 & - \\ \hline
[49] & 2015 & TiAlC/TiAlCN/TiAlSiO/TiAlSiOCO & SS & 95.5 & 7.0 & 82 & 87 \\ \hline
[66] & 2016 & Pt-Al\({}_{2}\)O\({}_{3}\) double cermet & SS/Glass & 92 & 13 & 500 & 87 \\ \hline
[97] & 2016 & W/WAIN/WAION/Al\({}_{2}\)O\({}_{3}\) & SS & 94.8 & 8.0 & 82 & - \\ \hline
[61] & 2017 & W/AlSiO\({}_{x}\):W(HA)/AlSiO\({}_{x}\):W(LA)/AlSiO\({}_{x}\) & SS & 95 & 11 & 400 & 86 \\ \hline
[50] & 2017 & TiAlNx/TiAlNy & Al\({}_{2}\)O\({}_{3}\) & 92.7 & 22.3 & 550 & - \\ \hline
[79] & 2017 & Cr/AlCrSiN/AlCrSiON/AlCrO & SS & 92.4 & 16 & 600 & - \\ \hline
[98] & 2018 & TiC-WC/Al\({}_{2}\)O\({}_{3}\) & SS & 92 & 11 & 82 & 82 \\ \hline
[99] & 2019 & Ti1-xAlxN & SS & 92 & 15 & 82 & 84 \\ \hline
[52] & 2020 & Al\({}_{2}\)O\({}_{3}\)/Mo-HfC & SS & 92 & 11 & 600 & - \\ \hline
[85] & 2020 & AlCrSiO & SS & 92.3 & 16 & 82 & - \\ \hline
[52] & 2020 & Nano-multilayered TiAlON & SS & 93.6 & 17 & 100 & - \\ \hline
[88] & 2021 & W/WAiSiN/SiO\({}_{2}\)/SiON & SS & 95.5 & 15.7 & 500 & 89.6 \\ \hline
[69] & 2022 & TiN/TiC-Ni/Mo\({}_{2}\)O\({}_{3}\) cermet & - & 90 & 2.80 & 800 & 85.9 \\ \hline
[72] & 2023 & Mo/SiO\({}_{2}\) & SS & 98.2 & 12.25 & 580 & - \\ \hline
[73,74] & 2023 & Ti/SiO\({}_{2}\) & Ti & 99.6 & 2.0 & 250 & - \\ \hline
[89] & 2023 & W/TiAlN/TiAlSiN/TiAlSiON/TiAlSiO & SS & 95.4 & 7.0 & 550 & - \\ \hline
[90] & 2024 & W/TiAlN/TiAlSiN/TiAlSiON/TiAlSiO & SS & - & 22 & 600 & - \\ \hline
[91] & 2024 & Nano-multilayered W/SiO\({}_{2}\) & - & 95.04 & 15.91 & 1000 & 86.03 \\ \hline
[37] & 2024 & SiO\({}_{2}\)/PtAl\({}_{2}\)O\({}_{3}\)/Pt/PtAl\({}_{2}\)O\({}_{3}\)/CConOx/SiO\({}_{2}\) & SS & 96 & 10.3 & 550 & - \\ \hline \hline \end{tabular}
\end{table}
Table 2: Optical characteristics and photoconversion efficiency of various STSCs.  
to maximize the capture of solar radiation and improve thermal performance at various temperature ranges.