Extreme high-temperature effects on optical response of CsPbBr3 perovskite

Abstract

The temperature sensitivity of CsPbBr3 perovskite impacts the performance of related devices, with their optoelectronic behavior characterized by the dielectric function (ε = ε1+iε2). Yet, research on optical properties (ε) beyond 200 °C remains limited, hindering the evaluation of their high-temperature stability. This study first grew a high-quality CsPbBr3 single crystal, then examined its dielectric function from −55 to 550 °C using spectroscopic ellipsometry, and explored the optical response of all-dielectric CsPbBr3-based metasurfaces under varying temperatures. High temperature induces dynamic disorder in CsPbBr3, and thermal decomposition initiates above 300 °C, leading to a substantial change of dielectric function. CsPbBr3-based metasurfaces exhibit near-perfect light absorption (average 0.987) with only a meta-atomic height equivalent to one-seventh of the wavelength. They also demonstrate enhanced absorption at longer wavelengths, attributed to high-temperature-enhanced magnetic resonance. This work aims to improve the high-temperature performance of CsPbBr3 perovskites and expand their applications in energy and ultrafast optics.