Tunable transport and optoelectronic properties of monolayer black phosphorus by grafting PdCl2 quantum dots. Issue 61 (15th October 2018)

• Record Type: Journal Article
• Authors: Sun, Cuicui; Wang, Yuxiu; Jiang, Yingjie; Yang, Zhao-Di; Zhang, Guiling; Hu, Yangyang
• Is Part Of: RSC advances. Volume 8:Issue 61(2018)
• Page Start: 35226
• Page End: 35236
• Publication Date: 2018-10-15
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra07053a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The photoelectric properties of the coordination functionalized monolayer black phosphorus by PdCl2 quantum dots are revealed for the first time. Abstract : The electronic, transport, and optoelectronic properties of monolayer black phosphorus (MLBP) are much influenced by grafting PdCl2 groups, demonstrated here by using density functional theory (DFT) and non-equilibrium Green's function (NEGF) as well as the Keldysh Nonequilibrium Green's Functions (KNEGF) methods. We find that the PdCl2 groups prefer to locate over the furrow site of MLBP and form a planar quadridentate structure of . The PdCl2 groups serve as quantum dots by introducing discrete flat levels between the MLBP valence band and the Fermi level ( E f ). The conductivity is much lowered after attaching PdCl2 quantum dots, due to the fact that the scattering effect of PdCl2 plays a major role in the process of electron transporting. A threshold voltage is found for the functionalized system with a large density of PdCl2 quantum dots, a valuable clue for exploring current switches. However, no evident threshold voltage is found for the pure MLBP. Electrons permeate easier through the armchair direction compared with the zigzag either in the pure MLBP or in the functionalized composites. More importantly, grafting PdCl2 quantum dots is very beneficial for enhancing photoresponse. The values of photoresponse for the modified species are about 20 times higher than the free MLBP. A significant photoresponse anisotropy is observed for both MLBP and n PdCl2 -BP ( n = 1, 2, and 4), contrary to the conductivity, the zigzag direction shows much stronger photoresponse than the armchair. All of the aforementioned unique properties make these new two-dimensional (2D) MLBP based materials especially attractive for both electronic and optoelectronic devices.