Fractional-order nonlocal wave propagation in hygro-piezo-photo-thermoelastic semiconductors with dual-moisture diffusion and laser excitation

This study investigates the propagation of coupled waves in a nonlocal hygro-piezo-photo-thermoelastic semiconductor medium subjected to dual-moisture diffusion and fractional-order heat conduction. The mathematical model incorporates the effects of long-range nonlocal interactions, piezoelectric coupling, photothermal excitation, and dual-moisture transport mechanisms. A time-fractional Caputo derivative is introduced into the energy equation to account for memory-dependent heat conduction. The coupled system of partial differential equations governing displacement, temperature, carrier density, electric potential, and moisture concentration is analytically solved using the normal mode analysis. Numerical results are presented for cadmium selenide (CdSe) semiconductor material to evaluate the impact of fractional order, nonlocal parameter, pulsed laser excitation, and dual-diffusion effects on wave characteristics. The findings reveal that fractional and nonlocal effects significantly influence wave speed, attenuation, and coupling behavior, offering essential insights for the design of next-generation MEMS, sensors, and optoelectronic devices operating in humid or thermally transient environments.