Journal Article

Unraveling the optoelectronic properties of CoSbx intrinsic selective solar absorber towards high-temperature surfaces

Taranova, Anastasiia, Yusupov, Khabib, Moretti, Elisa, Rosen, Johanna, Balliana, Eleonora, Morandi, Vittorio, Vomiero, Alberto, Moras, Paolo, You, Shujie, Mauri, Silvia, Gradone, Alessandro, Akbar, Kamran, Polewczyk, Vincent

2023

Overview

The combination of the ability to absorb most of the solar radiation and simultaneously suppress infrared re-radiation allows selective solar absorbers (SSAs) to maximize solar energy to heat conversion, which is critical to several advanced applications. The intrinsic spectral selective materials are rare in nature and only a few demonstrated complete solar absorption. Typically, intrinsic materials exhibit high performances when integrated into complex multilayered solar absorber systems due to their limited spectral selectivity and solar absorption. In this study, we propose CoSb x (2 < x < 3) as a new exceptionally efficient SSA. Here we demonstrate that the low bandgap nature of CoSb x endows broadband solar absorption (0.96) over the solar spectral range and simultaneous low emissivity (0.18) in the mid-infrared region, resulting in a remarkable intrinsic spectral solar selectivity of 5.3. Under 1 sun illumination, the heat concentrates on the surface of the CoSb x thin film, and an impressive temperature of 101.7 °C is reached, demonstrating the highest value among reported intrinsic SSAs. Furthermore, the CoSb x was tested for solar water evaporation achieving an evaporation rate of 1.4 kg m −2 h −1 . This study could expand the use of narrow bandgap semiconductors as efficient intrinsic SSAs with high surface temperatures in solar applications. The efficiency of CoSb x (where 2 < x < 3) as a selective solar absorber is investigated. Here, authors demonstrate that CoSbx endows broadband solar absorption (0.96) and simultaneous low emissivity (0.18), making it a promising material for use in solar energy systems.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 147/135 / 147/143 / 639/301/357/995 / 639/4077/4072/4062 / 639/925/357/354 / Absorption / Broadband / Emissivity / Energy gap / Evaporation / Evaporation rate / High temperature / Humanities and Social Sciences / Infrared radiation / multidisciplinary / Optoelectronics / Physics / Radiation / Science / Science (multidisciplinary) / Selectivity / Solar energy / Solar energy absorbers / Solar energy conversion / Solar radiation / Surface chemistry / Surface temperature / Thin films