X-ray absorption near edge structure of bulk and two-dimensional Na2Po: A testbed for scientific research

Abstract

Disodium Polonide in its two-dimensional phases are well-examined and have exceptional structural, electronic, vibrational, optical and thermoelectric properties. Utilizing WIEN2k DFT simulation software the ground state attributes of 1T and 1H phases of Na₂Po are computed and in both the phases it possesses structural and vibrational stability. Additionally, the thermal stability of 1T and 1H phases of Na₂Po was carried out by Ab- Initio molecular dynamics (AIMD) in the NVT ensemble for 3 different temperatures 300 K, 600 K and 1000 K up to 3ps with a time step of 1 fs. Both 1T and 1H phases of Na₂Po are thermally stable. Moreover, 1T and 1H-Na₂Po may have profound UV protectant and UV photodetectors that are briefly studied through their optical responses. The thermoelectric properties were carried out with BoltzTraP code for both phases. The figure of merit (ZT) at 300K of 1T-Na₂Po and 1H-Na₂Po is found to be 0.756 and 0.640, respectively. Hence, 1T-Na₂Po is more suitable than 1H-Na₂Po to design a waste heat recovery system. The XANES calculation was performed for Po L_III edge of both 3D and 2D (1T and 1H) phases of Na₂Po.