First-principles calculations to investigate Structural, electronic, elastic, optical and thermoelectric properties of BGaN₂ bilayer systems

Encouraged by the versatile applications of 2D materials in advanced technologies, we conducted a comprehensive investigation into the temperature-dependent thermoelectric, mechanical, and optoelectronic properties of BGaN₂ bilayer. To ensure the thermodynamic stability, we calculated the binding energies of the system while dynamic stability was verified through phonon dispersion curve. The electronic study indicate that band gap reduced compared to the pristine system and is found to be 0.04 eV. Further mechanical stability is ensured by calculating the elastic constants. The mechanical properties indicate that system has an anisotropic nature. Optical property evaluation reveals that systems has good optical absorption in the visible regions, making them promising for optoelectronic applications. Furthermore, the X-direction exhibits a broader range of absorption compared to the Y-direction, indicating stronger and more extensive electronic transitions in this orientation. Additionally, we calculated the thermoelectric properties and found that Seebeck coefficient have directional dependency. The lattice thermal conductivity along the Y-direction is higher than that of along X-direction. In addition, the ZT is greater in the Y-direction and found to be 1.44 while along X-direction for p-type carrier it becomes 1.2 at same temperature. Our findings provide valuable insights into the fundamental properties of BGaN₂ bilayer, highlighting its potential for next-generation thermoelectric and optoelectronic applications.