Structural, Elastic, Mechanical, Electronic and Optical Properties of TlSnX3(X=Cl, Br, I) for Sustainable Energy Applications

Cubic halide based perovskite gained the attention of the researchers due to their remarkable optoelectronic contributions. The present work deals with the first principles calculations based on Density Functional Theory for exploring the TlSnX3(X=Cl, Br, I) cubic perovskites. The important physical characteristics are computed within Wien2k using Full Potential Linearized Augmented Plane wave, FP-LAPW method. The structural stability is examined by energy volume optimization. The optimized lattice constant of TlSnCl3 and TlSnI3 is 5.58 & Aring;, 5.83 & Aring; and 6.20 & Aring;. The electronic and optical properties are calculated using Generalized Gradient Approximation with Perdew-Burke-Ernzerhof, PBE-GGA, Trans-Blaha modified Becke-Johnson, TB-mBJ and Strongly Constrained and Appropriately Normed, SCAN exchange and correlation functionals. The studied compounds possess direct band gap nature with the band gap of 1.61 eV, 1.08 eV and 0.75 eV with TB-mBJ for TlSnCl(3 )and TlSnI3 . The band gap using PBE-GGA(SCAN) potentials for TlSnCl3 , TlSnBr3 is 0.98 (0.78) eV, 0.67 (0.69) eV and 0.50 (0.48) eV, respectively. The mechanical analysis reveal that these compounds are ductile. The optical characteristics like epsilon(omega) , n(omega) , alpha(omega) , R(omega) , sigma(omega) and L(omega) are calculated by implementing PBE-GGA, TB-mBJ and SCAN XC. High absorption and low reflectivity make these perovskites potential candidates for sustainable energy applications.