Electrical Response of a Piezoelectric Semiconductor PN Junction Under a Local Temperature Change: A Three-Interface Analytical Model

Piezoelectric semiconductor PN junctions hold considerable promise for self-powered sensing, flexible electronics, energy harvesting, photodetection, and multifunctional micro/nanodevices. A local temperature change couples the built-in electrical response of the PN doping interface with the thermally induced response at the boundaries of the heated region, thereby modifying the electric potential, electric field, electric displacement, and carrier distributions near the junction. To elucidate this coupling mechanism, a one-dimensional three-interface analytical model is developed for a piezoelectric semiconductor PN junction subjected to a local temperature change. The fiber is divided into cold P-type, heated P-type, heated N-type, and cold N-type regions, and the coupled response is determined using piecewise analytical solutions together with open-circuit end conditions, interface continuity conditions, global carrier-conservation constraints, and reference-point conditions. Within a linear small-perturbation framework for an ideal zero-thickness homojunction, numerical results show that the PN doping interface governs the baseline distributions of the built-in potential and electric field, whereas the temperature interfaces generate additional electric fields through temperature-induced electric-displacement compensation, leading to localized redistribution of holes and electrons. For the baseline ZnO case with a 0.5 K temperature increment, the potential span is 9.124 mV, the peak electric-field magnitude is 48.43 kV m−1, and the maximum carrier perturbation is 0.180 of its regional reference concentration. Independent Galerkin finite-element calculations agree with the analytical solution, with a maximum normalized discrepancy of 0.553% on the finest mesh. The temperature-change amplitude, heated-region half-width, reference carrier-concentration level, P/N doping asymmetry, effective dielectric constant, and effective thermal electric-displacement coefficient modify the potential transition, electric-field peaks, and carrier-screening range near the junction. These results reveal the coupled interaction between the local temperature interfaces and the PN doping interface and provide a theoretical basis for thermally regulating piezoelectric semiconductor junction devices under localized thermal loading.