Efficient charge separation and visible-light response in bilayer HfS2-based van der Waals heterostructures. Issue 34 (23rd May 2018)

• Record Type: Journal Article
• Authors: Wang, Biao; Luo, Xukai; Chang, Junli; Chen, Xiaorui; Yuan, Hongkuan; Chen, Hong
• Is Part Of: RSC advances. Volume 8:Issue 34(2018)
• Page Start: 18889
• Page End: 18895
• Publication Date: 2018-05-23
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra03047b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : In this work, we employ hybrid density functional theory to investigate HfS2 -based van der Waals (vdW) heterojunctions for highly efficient photovoltaic and photocatalytic applications. Abstract : Two-dimensional (2D) hafnium disulfide (HfS2 ) has been synthesized and is expected to be a promising candidate for photovoltaic applications, and at the same time the hexagonal BN sheet (h-BN) and graphene-like C3 N4 sheet (g-C3 N4 ) have also been fabricated and are expected to be applied in photocatalysis. In this work, we employ hybrid density functional theory to investigate HfS2 -based van der Waals (vdW) heterojunctions for highly efficient photovoltaic and photocatalytic applications. HfS2 /h-BN and HfS2 /g-C3 N4 heterostructures with direct bandgaps and efficient charge separation are both typical type-II semiconductors and have potential as photovoltaic structures for solar power. Moreover, compared with h-BN and g-C3 N4 single-layers, HfS2 /h-BN heterostructures with 6% tensile strain and HfS2 /g-C3 N4 heterostructures with 9% tensile strain have moderate bandgaps, whose optical absorption is obviously enhanced in the ultraviolet-visible (UV-VIS) light range and whose bandedges are suitable for photocatalytic water splitting. HfS2 /h-BN heterostructures with 6% applied strain, being different from HfS2 /g-C3 N4 heterostructures with 9% strain, possess a direct bandgap and show complete separation of the photoinduced electron–hole pairs. Thus the HfS2 /h-BN heterojunction with 6% strain has bright prospects for use in visible light photocatalytic water splitting to produce hydrogen.