Doping of aluminum (Al) into copper sulfide (CuS) nanocrystals enhanced their solar spectral selectivity

Abstract

Herein, aluminum-doped copper sulfide (Al-CuS) nanocrystals were prepared by the hydrothermal method. Al³⁺ was successfully doped into CuS, and the Al-CuS nanocrystals presented a single phase of the covellite structure similar to pure CuS. The optical band gap energy (E_g) of Al-CuS was in the range of 1.74–2.00 eV. Subsequently, to clearly understand the optical properties of the Al-CuS nanocrystals, the Al-CuS nanocrystals were distributed among polyvinyl alcohol (PVA) to fabricate a film with low near-infrared (NIR) light transmittance (800–2500 nm) and high visible-light transmittance (400–800 nm); herein, we demonstrated that the doping of aluminum (Al) into copper sulfide (CuS) nanocrystals enhanced the solar spectral selectivity of these crystals.