Design of high-mobility p-type GaN via the piezomobility tensor

Gallium nitride (GaN) is a wide-bandgap semiconductor crucial for applications in power electronics, radio-frequency devices, and solid-state lighting. A significant challenge in advancing p-channel devices is GaN's low intrinsic hole mobility, which limits its integration into next-generation technologies. Although various specific strain conditions have been explored to enhance hole mobility, a comprehensive analysis of all possible strain conditions is still needed. In this study, we introduce a linear tensor equation to characterize the relationship between applied strain and hole mobility in GaN. We solve the ab initio Boltzmann transport equation for hole mobilities under different strain conditions. We identify three optimal configurations, two uniaxial strains and one shear strain. This methodology provides a general framework for first-principles-based engineering of semiconductor transport properties through strain manipulation and a fast-screening scheme of strain condition search.