Exploring Pressure-Induced Changes in the Electronic, Mechanical and Optical Properties of Inorganic Sr₃ AsI₃ Perovskite

Recently, inorganic halide perovskite solar cells have garnered significant attention. They show great promise due to their remarkable properties like high efficiency, low cost, and easy availability making them fascinating candidates for next-generation photovoltaic technology. Among these, lead-free Sr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>AsI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> inorganic perovskites emerged as a class of materials possessing promising optoelectronic and mechanical properties that make them ideal candidates for photodetector applications due to their remarkable UV optical response. In the present investigation, first principles in density functional theory calculations have been performed using Material Studio to thoroughly examine strain-driven electrical and optical properties as well as mechanical characteristics of Sr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>AsI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>. The Sr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>AsI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> compound has a direct band gap in the absence of pressure only at G-point, 1.171 eV. By applying hydrostatic pressure, we can further tune the band gap opening and reduce it. On the other hand, a red shift in the absorption spectra and dielectric function was observed under compressive strain; moreover, it moved to higher energies with tensile strains. The Sr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>AsI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> perovskite possesses high mechanical stability and ductility, which are confirmed by its strain-dependent mechanical properties, making it suitable for a wide range of applications. The strain-sensitive mechanical and optoelectronic properties suggest that Sr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>AsI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> has potential applications in future developments of optical-electrical-conversion technologies.