Polarization-Induced Electrostatic Doping in 2DHG of Hydrogenated Diamond

Hydrogen-terminated diamond (H-diamond), a wide-bandgap semiconductor with excellent thermal conductivity and high carrier mobility, has emerged as a promising candidate for next-generation and power device ultraviolet photodetector applications. However, the precise and reversible modulation of two-dimensional (2D) hole gas (2DHG) in H-diamond remains a significant challenge due to the limitations of conventional doping techniques, which often introduce structural defects and degrade carrier mobility. In this study, we employ first-principles calculations to propose a ferroelectric (FE) polarization-driven electrostatic doping strategy for achieving tunable band alignment and carrier redistribution in α-In2Se3/H-diamond van der Waals (vdW) heterostructures. We demonstrate that the interfacial band alignment can be reversibly switched by manipulating the polarization direction and thickness of α-In2Se3. This polarization-induced electrostatic doping enables precise control over the carrier type and concentration across the heterojunction. Moreover, the interfacial polarization within the heterostructures can be enhanced by increasing the number of FE layers, thus amplifying these polarization-dependent effects. Furthermore, polarization switching significantly enhances light absorption in the visible to near-infrared regions. This work provides theoretical insights into polarization-induced electrostatic doping in wide-bandgap semiconductors and highlights the potential of α-In2Se3/H-diamond heterostructures for next-generation power device and optoelectronic applications.