Anomalous doping effect in black phosphorene using first-principles calculations

Abstract

Using first-principles density functional theory calculations, we investigate the geometries, electronic structures, and thermodynamic stabilities of substitutionally doped phosphorene sheets with group III, IV, V, and VI elements. We find that the electronic properties of phosphorene are drastically modified by the number of valence electrons in dopant atoms. The dopants with even number of valence electrons enable the doped phosphorenes to have a metallic feature, while the dopants with odd number of valence electrons keep a semiconducting feature. This even-odd oscillating behavior is attributed to the peculiar bonding characteristics of phosphorene and the strong hybridization of sp orbitals between dopants and phosphorene. Furthermore, the calculated formation energies of various substitutional dopants in phosphorene show that such doped systems can be thermodynamically stable. These results propose an intriguing route to tune the transport properties of electronic and photoelectronic devices based on phosphorene.Keywords: electronic properties, substitutional doping, phosphorene 1.IntroductionThe discovery of graphene has opened many new areas of research related with two-dimensional (2D) atomiclayer systems such as transition metal dichalcogenides (TMDCs), silicene, germanane, and so on. 1-4 All of them have attracted much attention as promising materials for future electronics applications. 5,6 Most recently, fewlayer black phosphorus (BP) was successfully fabricated through exfoliation techniques, 7 and especially monolayer BP (termed phosphorene) becomes another stable elemental 2D material. Because of its intriguing electronic properties, phosphorene has drawn much attention of both experimental and theoretical works. [8][9][10][11][12][13][14][15] Interestingly, few-layer BP has been theoretically predicted to have a direct gap or a nearly direct gap ranging from 0.8 to 2 eV depending on the layer thickness. 8 It was reported that phosphorene has a high carrier mobility of ∼10 3 cm 2 /V . s and an on/off ratio of ∼10 4 at room temperature, thus being considered as a novel channel material in field effect transistors. Recently, Shao et al 16 predicted that phosphorene would be a potential superconductor material through electron-doping, and Jing et al 17 investigated the optical properties of phosphorene by molecular doping. These exotic electronic properties of phosphorene can be utilized for the development of future nanoelectronic devices. [18][19][20] Doping in 2D materials is of fundamental importance to enable a wide range of optoelectronic and electronic devices by tuning their electronic properties. For graphene, it has been well established that carrier concentration can be modulated by charge-transfer doping with adsorbed atoms, molecules, and clusters. [21][22][23][24][25] Here, the Fermi level can be shifted above or below the Dirac point depending on n or p doping, respectively. 26 Alternatively, substitutional doping in graphene with heteroatoms provides an effective route for ...

Atomically thin binary V–V compound semiconductor: a first-principles study

“…The calculated band structure, along with the corresponding density of states for α-AsP, as presented in Fig. 4 (a), suggest that the fundamental band gap value E g =1.01 eV is slightly larger than that of α-P counterpart (0.91eV) 23 . The band structure near the top of the valence band shows a remarkable anisotropy comparing the Γ→X and Γ→Y directions.…”

“…The monolayer structures have been optimized using DFT with the PBE exchange-correlation functional, as discussed in the methods section. The calculated structural parameters and cohesive energy of monolayer were listed in Table 1 23 and (a 1 =a 2 =3.33Å). 24 The cohesive energies of α-phase are -6.76, -6.02, -5.73, -4.31, -4.51, -4.26 eV/atom, respectively.…”

Sulfur‐Doped Phosphorene as a Promising Anode for Na and K‐Ion Batteries

“…However, this apparent quasi‐one‐dimensional diffusion that observed in S‐doped BP does not exist in other two‐dimensional materials. More interestingly, the electronic properties of S‐doped BP systems give rise to metallic characteristics due to the strong hybridization of sp orbitals between dopant S and BP . In contrast, the Na diffusion in monolayer H‐passivated silicene, boron‐doped graphene, and MoS 2 are essentially isotropic in the plane with the values of diffusion barrier being 0.12 eV on monolayer H‐passivated silicene, 0.16–0.22 eV on boron‐doped graphene, 0.28 eV on MoS 2 ,which are larger than that along the zigzag direction on S‐doped BP.…”

A first-principles study of light non-metallic atom substituted blue phosphorene

“…Doped 2D materials are, therefore, useful for various applications including energy storage [4][5][6][7][8], energy conversion [9,10], and sensing [11][12][13][14]. Also, there are abundant works [15][16][17][18][19][20][21][22][23][24][25][26] focusing on the domain of nanoelectronics. For instance, monolayer MoS 2 doped by transition metals can be used as a two-dimensional diluted magnetic semiconductor [25,26].…”