Abstract <p>This study presents a theoretical and analytical model for the dynamic behavior of a nonlocal photo-thermoelastic semiconductor plate incorporating moisture diffusion and subjected to ramp-type heating. The formulation couples photoexcited carrier density, heat conduction, and moisture transport with Eringen’s nonlocal elasticity, enabling the analysis of size-dependent effects relevant to nanoscale devices. The governing equations are expressed in a dimensionless form and solved analytically using Laplace and Fourier transformations, yielding exact expressions for displacement, stress, temperature, carrier density, and moisture fields. The results show that ramp-type heating smooths transient responses and mitigates thermal shocks, while nonlocal elasticity markedly reduces stress magnitudes, delays wave propagation, and alters dispersion characteristics, leading to enhanced stability and energy dissipation at the nanoscale. The analysis further reveals that coupled photo-thermoelastic–moisture interactions significantly influence wave attenuation and field oscillations, demonstrating the necessity of including nonlocal and diffusive effects for accurate predictions. These findings provide new insights into the design and optimization of micro- and nano-scale semiconductor devices, including photonic sensors, optoelectronic systems, and thermal management structures.</p>