Exploring the impact of Cl and Br doping on the key physical properties of CsTaO3 for optoelectronic and thermoelectric applications

초록

First-principles density functional theory (DFT) simulations, implemented by the WIEN2K code, are used to investigate the effects of Cl and Br doping on the host material. Powder X-ray diffraction reveals a shift of diffraction peaks to lower angles, indicative of crystal lattice expansion and changes in the material's lattice features. The molecular dynamics demonstrate constant oscillations over an average value, implying that the whole system is in a condition of thermal equilibrium. Doping Cl and Br with CsTaO3 induces a metallic nature. The optical properties of CsTaO3, CsTaO3-xClx, and CsTaO3-xBrx have been thoroughly investigated up to the 14 eV energy range. The calculated optical constants reveal that CsTaO3, CsTaO3-xClx, and CsTaO3-xBrx exhibit substantial photon absorption in the ultraviolet domain. The positive Seebeck coefficient value indicates that CsTaO3 is a p-type semiconductor, but CsTaO3-xClx and CsTaO3-xBrx exhibits an n-type character. The CsTaO3, with a band gap of 2.778 eV, collectively with its doped derivatives CsTaO3-xClx and CsTaO3-xBrx, are particularly suitable for energy efficient optoelectronic devices.

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