A DFT Study of Bandgap Engineering and Tuning of Structural, Electronic, Optical, Mechanical and Transport Properties of Novel [Ba₄Sb₄Se₁₁]: Sr³⁺ Selenoantimonate for Optoelectronic and Energy Exploitations

The comprehensive first-principles analysis of Ba₄Sb₄Se₁₁ and [Ba₄Sb₄Se₁₁]:Sr³⁺ Selenoantimonate Using DFT demonstrates its semiconductor nature, anisotropic ductile properties, and prospective optoelectronic applications, particularly in solar cells and LED technologies, supported by comprehensive structural, electronic, optical, and mechanical studies. All the relevant parameters were determined in this investigation using the framework of DFT by modified Becke Johnson approximations. These parameters include the extinction coefficient, absorption coefficient, energy loss function, reflectivity, refractive index, optical conductivity, and birefringes. The elastic parameters have been calculated based on anisotropic sound velocities and mechanical stability. These parameters include bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio. Based on an analysis of the energy band dispersions, it can be concluded that the examined compounds possess semiconductor properties. The data on elastic parameters suggest that the material exhibits anisotropic and ductile characteristics, which could have potential applications in optoelectronics. The Ba₄Sb₄Se₁₁ (2.2 eV) and [Ba₄Sb₄Se₁₁]: Sr³⁺ (1.68 eV) have a direct band gap, which falls within the visible spectrum showing semiconducting nature. The analysis of the thermoelectric properties of investigated compounds has been conducted using the Boltztrap code, marking a significant in scientific research. The study revealed that these compounds have the potential to be utilized in highly challenging transport conditions. Additional investigations and cooperation are essential for understanding the fundamental processes and enhancing the material for effective utilization in various technological applications for solar cells and LED in the energy and optoelectronic industry.