Photoacoustic dynamics in microtemperature semiconductor media with variable thermal conductivity and nonlocal effects

Abstract

The study investigates the photoacoustic pressure effects on microtemperature distributions within a nanostructured (nonlocal) elastic semiconductor medium, where thermal conductivity is considered variable. Photoacoustic phenomena, which involve the generation of acoustic (elastic) waves due to the absorption of modulated light, play a pivotal role in heat transfer dynamics at the nanoscale. The interaction between photoacoustic pressure, plasma waves, and thermal waves influences localized temperature variations in semiconductor nanostructures. The variable thermal conductivity, which accounts for temperature dependence and nanoscale effects, adds complexity to the heat diffusion process. Using mathematical modeling and numerical simulations, the photoacoustic pressure-driven thermal response is analyzed in one dimension (1D) under different excitation frequencies and thermal conductivity profiles. Results show that the variable thermal conductivity significantly affects the propagation of thermal waves, acoustic pressure, elastic, mechanical, microtemperature, and carrier density diffusion, leading to enhanced heat confinement or dispersion depending on material properties and operating conditions. The findings have implications for the design of semiconductor devices where thermal management is critical, such as in photodetectors, microelectronic systems, and optoelectronic devices. This research advances the understanding of nanoscale heat transfer mechanisms in semiconductors under photoacoustic excitation and provides insight into optimizing thermal performance in nanostructured materials.

Graphical abstract