Theoretical investigation of the role of hydrogenation-induced strain in single-layer h10-Si

• Published in: Physical chemistry chemical physics : PCCP 2022-12, Vol.25 (1), p.203-208
• Main Authors: Zhang, Deju, Jiang, Peng, Hong-Mei, Huang, Zhang, Yanning, Yan-Ling, Li
• Format: Article
• Language: English
• Subjects: Density functional theory; Dipoles; Electromagnetic absorption; Energy levels; Equivalence; Hydrogenation; Optical properties; Physical properties; Tuning; Two dimensional materials
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp04855h

Although great efforts have been dedicated to exploring hydrogenated two-dimensional (2D) materials, there are few reports about the role of hydrogenation-induced equivalent strain effects in tuning the physical properties. Here, based on density functional theory, we systematically reveal the non-negligible role of the hydrogenation-induced strain and its effects on the electronic and optical properties in single-layer (SL) h10-Si. We demonstrate that hydrogenation can trigger an electronic transition from an indirect- to a direct-band-gap semiconductor mainly due to the energy level rearrangement of the partial p orbitals caused by the equivalent strain. The electronic transition in SL h10-Si occurs at a critical hydrogenation concentration of about 87.5%. Furthermore, it is found that hydrogenation can continuously shift the light absorption peak of SL h10-Si in the photon-energy range of 1.64–2.44 eV by changing the pz–pz dipole transition. Our findings provide an example of tuning the electronic properties of 2D materials via hydrogenation-induced strain, which is important for understanding the physical mechanism of the hydrogenation-tuned physical properties of such materials.