Strain-Induced Corrugation and Its Impact on Electronic and Optical Properties of hBN-GaS, -GaSe, and -InS heterostructures

Two dimensional group IIIa monochalcogenides are promising two-dimensional semiconductors, known for their high carrier mobility and strong optical absorption in the visible and UV range. When integrated with hexagonal boron nitride (hBN) in van der Waals heterostructures, these materials benefit from the atomically flat and inert nature of hBN, which helps preserve their intrinsic electronic quality and enhances overall device performance. In our previous studies, hBN-based heterostructures with these monolayers exhibited favorable band alignment and optoelectronic characteristics.In this work, we investigate the role of strain in shaping the structural and electronic behavior of hBN/GaS, hBN/GaSe, and hBN/InS heterostructures using first-principles DFT calculations. Contrary to heterostructures previously reported in the literature, these three systems develop a pronounced corrugated geometry as a result of compressive strain and lattice mismatch. We analyze how this strain-induced out-of-plane distortion modifies interlayer coupling, charge redistribution, band structure, and optical absorption spectra.