Interfacial control of boundary-laser-driven photo-thermoelastic wave dynamics in imperfect semiconductor heterojunctions

Rapid laser excitation of semiconductor heterojunctions produces localized temperature gradients, carrier accumulation, and interfacial stresses that can impair device performance and reliability. This study develops a two-dimensional photo-thermoelastic model to determine how mechanical, thermal, and electronic interface imperfections control coupled wave transmission across a GaAs/ Al 0.3 Ga 0.7 As heterojunction. Its main contribution is the simultaneous treatment of finite normal and tangential stiffnesses, Kapitza thermal resistance, band-dependent carrier partition, limited carrier transfer, and interfacial recombination. For surface-absorbing or optically coated devices with negligible penetration depth, the laser is represented by prescribed heat and photocarrier fluxes at the illuminated boundary without volumetric generation. Generalized thermoelasticity, dual-phase-lag heat conduction, and carrier diffusion are coupled in each semiconductor. Helmholtz decomposition and normal-mode analysis identify the thermal, carrier, longitudinal, and shear modes. Reducing normalized interface stiffness from 10 to 0.1 decreases peak normal stress by approximately 48% and increases displacement discontinuity. Increasing normalized Kapitza resistance from zero to one creates a temperature jump of approximately 0.09. Reducing carrier transfer from 10 to 0.1 decreases transmitted carrier density by about 45%, while stronger recombination reduces interfacial carrier density by approximately 50%. The model provides a unified framework for evaluating laser-induced responses in optoelectronic and thermal-management devices under operating conditions.