Investigating structural, optoelectronic, and mechanical properties of europium-based halide perovskite CsEuBr3 for photovoltaic applications: a DFT approach

Halide perovskites, known for their fantastic properties and flexible chemistry, have substantial impact for advancing photovoltaic technology. In this study, the potential of europium (Eu)-based halide perovskite, i.e.; CsEuBr3, was investigated using DFT within the framework of WIEN2K code. Investigation covered its fundamental properties, including structural, optoelectronic, elastic, mechanical, as well as formation energy and phonon dispersion phenomena. The dynamic stability was confirmed from the negative value of formation energy (- 2.147 eV) and stable phonon dispersion. Electronically, band gap of 1.2 eV was observed, makes it highly suitability for photovoltaic applications. From optical perspective, material exhibit high optical absorption, conductivity, and lower loss function. The elastic constants (C11, C12, and C44) nicely pursue the Born stability criteria suggested the mechanical stability of CsEuBr3. Other derived mechanical parameters, such as anisotropy, Poisson's ratio (nu), and Pugh's ratio (B/G), confirmed that CsEuBr3 is more anisotropic and ductile. Thermal behavior evaluated through the Debye temperature (theta(D)) further supported its stability. These findings confidently suggested the potential of the considered halide perovskite, CsEuBr3, as a promising candidate for photovoltaic applications.