First-Principles Calculations Innovation in Wide Bandgap Semiconductors: Multiphysics Field Coupling and Functional Device Design

Wide bandgap semiconductors have become the core material system for high-power electronic devices, deep-ultraviolet optoelectronic devices, and quantum information technology, featuring high-temperature stability and optoelectronic properties. First-principles calculations play an irreplaceable role in revealing the intrinsic physical properties of materials, guiding the optimization of energy-band engineering, and predicting the performance of devices through accurate modeling at the quantum mechanical level. This paper systematically reviews the key advances of first-principles calculations in wide bandgap semiconductor research in recent years: from the theoretical breakthroughs in electronic structure calculation and bandgap correction to the multiscale modeling of photoexcitation dynamics and thermal transport behavior; from the innovative design of defect formation mechanisms and doping strategies to the prediction of the performance of low-dimensional materials and heterojunction devices. The review shows that by integrating multi-body perturbation theory, machine learning algorithms, and dynamic simulation technology, first-principles calculations promote the paradigm shift from empirical exploration to theory-driven research on wide bandgap semi-conductors, and the material-performance-device-function correlation model established by the study will lay the theoretical foundation for the breakthrough development of new-generation semiconductor technology.