Twist-angle modulation on bandgaps in twisted bilayer γ-graphyne and graphdiyne

In semiconductor technology, bandgap engineering is a cornerstone challenge that continues to evolve. By employing the full and low-energy tight-binding model, we focused on the effects of twist-angle on the bandgaps of twisted bilayer gamma-graphyne and graphdiyne. Our results indicated that reducing the twist-angle from 21.79 degrees to 0.67 degrees can significantly narrow the bandgap by as much as 0.5 eV. Drawing on the concept of hybridization, this reduction in bandgap is elucidated by the average of the interlayer coupling on the valence band maximum state and conduction band minimum state. Our research presents a versatile approach to bandgap modulation in two-dimensional semiconductors.