Direct Band Gaps in Group IV-VI Monolayer Materials: Binary Counterparts of Phosphorene

Abstract

We perform systematic investigation on the geometric, energetic and electronic properties of group IV-VI binary monolayers (XY), which are the counterparts of phosphorene, by employing density functional theory based electronic structure calculations. For this purpose, we choose the binary systems XY consisting of equal numbers of group IV (X = C, Si, Ge, Sn) and group VI elements (Y = O, S, Se, Te) in three geometrical configurations, the puckered, buckled and planar structures. The results of binding energy calculations show that all the binary systems studied are energetically stable. It is observed that, the puckered structure, similar to that of phosphorene, is the energetically most stable geometric configuration. Our results of electronic band structure predict that puckered SiO and CSe are direct band semiconductors with gaps of 1.449 and 0.905 eV, respectively. Band structure of CSe closely resembles that of phosphorene. Remaining group IV-VI binary monolayers in the puckered configuration and all the buckled monolayers are also semiconductors, but with indirect band gaps. Importantly, we find that the difference between indirect and direct band gaps is very small for many puckered monolayers. Thus, there is a possibility of making these systems undergo transition from indirect to direct band gap semiconducting state by a suitable external influence. Indeed, we show in the present work that seven binary monolayers namely SnS, SiSe, GeSe, SnSe, SiTe, GeTe and SnTe become direct band gap semiconductors when they are subjected to a small mechanical strain (<= 3 %). This makes nine out of sixteen binary monolayers studied in the present work direct band gap semiconductors. Thus, there is a possibility of utilizing these binary counterparts of phosphorene in future light-emitting diodes and solar cells.

14 pages, 10 figures

References in corpus (10)

• The electronic properties of graphene
• Strain-Engineering Anisotropic Electrical Conductance of Phosphorene and Few-Layer Black Phosphorus
• Semiconducting layered blue phosphorus: A computational study
• Strain engineered direct-indirect band gap transition and its mechanism in 2D phosphorene
• Arsenene: Two-dimensional buckled and puckered honeycomb arsenic systems
• Photovoltaic effect in few-layer black phosphorus PN junctions defined by local electrostatic gating
• Unusual Scaling Laws of the Band Gap and Optical Absorption of Phosphorene Nanoribbons
• Electrically Tunable Quasi-Flat Bands, Conductance and Field Effect Transistor in Phosphorene
• Edge effects on the electronic properties of phosphorene nanoribbons
• Orientation and strain modulated electronic structures in puckered arsenene nanoribbons

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