Achieving indirect‐to‐direct band gap transition and enhanced photocatalytic performance in blue phosphorene through doping and strain. Issue 13 (30th March 2020)

• Record Type: Journal Article
• Authors: Wang, Jiajun; Li, Shengcai; Yun, Fengyi; Zhang, Xin; Li, Qunxiang
• Is Part Of: International journal of quantum chemistry. Volume 120:Issue 13(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-30
• Subjects: blue phosphorene -- doping -- indirect‐to‐direct band gap transition -- photocatalytic water splitting -- strain -- carrier mobility; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26230
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: Recently, blue phosphorene (BP) has demonstrated great potential in the field of photocatalytic water splitting due to the ultrahigh carrier mobility. However, the practical application of BP as an efficient photocatalyst is greatly limited by its indirect band gap. In this work, we investigate the synergistic effect of substitutional doping and biaxial strain on the electronic and photocatalytic properties of BP using hybrid density functional calculations. The results show that As/Sb doping not only reduces the band gap of BP without introducing any midgap states but also turns it into direct band gap semiconductor, which can be ascribed to the p states of the dopants appearing around the band edges. For these As/Sb‐doped BP systems, the band gaps, band edge positions, and optical absorption abilities can be further tuned by applying a biaxial strain. In particular, we predict that compressive strains are more propitious for the doped systems than the tensile strains since the requirements for water splitting are satisfied, meanwhile preserving the direct band gap characteristics. Besides, our calculations also show that the band gap and the reducing and oxidizing power of multilayer BP are highly dependent on the layer thickness. These results suggest feasible modulation strategies for enabling BP to be a visible‐light‐driven photocatalyst for water splitting. Abstract : Density functional calculations show that band engineering via As/Sb doping enables blue phosphorene to possess a direct band gap and the desired band edge positions with adequate driving forces for water splitting. Besides, the photocatalytic performance of these doped blue phosphorene systems can be further modulated by applying biaxial strain.