Modulation of electronic properties and band alignment in h-BN/diamond heterostructures with various dopants under biaxial strain

Abstract

The h-BN/diamond mixed-dimensional heterostructure demonstrates significant potential in optoelectronic devices. This study investigates the optoelectronic properties of X doped h-BN (X = Al, Ga, P, As) / diamond (111) heterostructures using first-principles calculations under biaxial strain. The results reveal that different doping atoms influence the electronic structure and charge transfer direction in Al_B/Ga_B/Ga_N doped systems, all exhibiting type-II bandgaps. The h-BN/diamond heterostructure achieves a maximum light absorption coefficient of 6.7 × 10⁵ cm⁻¹ at 5.33 eV, while the light absorption peaks of other doped structures are reduced and shifted. The conduction band offset (CBO) for Al_B/Ga_B/Al_N/Ga_N doped systems is less than 1 eV, which increases leakage risks. Biaxial strains ranging from −6 % to 6 % induce a linear increase in bandgaps, effectively tuning their size. This tunability highlights the potential applications of these heterostructures in the design and fabrication of advanced optoelectronic devices.