Structural Stability, Elecctronic, Opticol, and Thermal Properties of III-V Ternary Semiconductors: AxB1_xC

Abstract

First-principles simulations were carried out to explore the structural stability, electronic, optical, mechanical and thermal properties of InxAl1−xY semiconductor alloys (Y = N, P, As, Sb and Bi) using Density Functional Theory (DFT) based on the FP-LAPW method integrated in WIEN2k code. For exchange – correlation energy, the Wu–Cohen generalized gradient approximation (WC - GGA) was considered to examine structural and mechanical properties. In addition, modified Becke – Johnson potential proposed by Koller et al (nKTB - mBJ) along with the Engel – Vosko GGA, were utilized to refine the potential for accurate band structure analysis. Structural results confirm that all alloys stable in the zinc blende phase, except Y = N which favors the wurtzite structure, while lattice constants and bulk moduli follow Vegard’s law. Electronic analysis reveals indirect-to-direct band gap transitions with indium incorporation, improving optical performance and extending spectral coverage from the ultraviolet to the near - infrared region. Optical results indicate strong absorption in UV – visible for nitrides and phosphides, while heavier alloys shift absorption toward the infrared region. Mechanical calculations demonstrate elastic stability with brittle behavior. Thermal analyses show high Debye temperatures and thermal conductivities for compounds (N, P), while Sb - and Bi - based alloys exhibit lower conductivity, larger thermal expansion, and higher vibrational entropy, which make them favorable for thermoelectric applications. Overall, InxAl1−xY alloys combine strong structural stability, tunable band gaps, diverse optical responses, and promising thermal features, making them suitable for applications in LEDs, photodetectors, solar cells, and thermoelectric generators