Janus $\beta$-Te${}_2$X (X = S, Se) Monolayers for Efficient Excitonic Solar Cells and Photocatalytic Water Splitting

Abstract

Highly efficient, environmental friendly and renewable sources of energy are of great need today to combat with increasing energy demands and environmental pollution. In this work, we have investigated the novel 2D allotropes i.e., $\beta$-Te${}_2$X (X = S, Se) using first-principles calculations and study their potential applications in light harvesting devices. Both the monolayers possess to have the high stability and semiconducting nature with an indirect band gap. The high carrier mobilities and excellent optical absorption of these monolayers make them potential candidates for solar conversion applications. We have proposed the type-II heterojunction solar cells and calculated their power conversion efficiencies (PCEs). The small conduction band offset and appropriate band gap of donor material in case of $\beta$-Te${}_2$S(S-Side)/$\alpha$-Te${}_2$S(Te-Side) heterojunction results in the PCE of ~ 21%. In addition to that, the band alignments of these monolayers properly engulf the redox potentials of the water. The overpotentials required to trigger the hydrogen reduction (HER) and water oxidation (OER) half reactions reveal that HER and OER preferred the acidic and neutral mediums, respectively. The calculated solar-to-hydrogen (STH) efficiencies of $\beta$-Te${}_2$S ($\beta$-Te${}_2$Se) monolayers come out to be ~ 13 % (~12 %), respectively, which implies their practical applications in water splitting. Thus, our work provides strong evidence regarding the potential applications of these materials in the field of light harvesting devices.

arXiv comment25 pages, 8 figures. Journal of Materials Chemistry C, 2023

References in corpus (16)

• Electric Field Effect in Atomically Thin Carbon Films
• Monolayer honeycomb structures of group IV elements and III-V binary compounds
• First-principles study of the phonon-limited mobility in n-type single-layer MoS2
• Yambo: an \textit{ab initio} tool for excited state calculations
• Superior mechanical flexibility of phosphorene and few-layer black phosphorus
• Arsenene: Two-dimensional buckled and puckered honeycomb arsenic systems
• Density-functional calculations of multivalency-driven formation of Te-based monolayer materials with superior electronic and optical properties
• Revised self-consistent continuum solvation in electronic-structure calculations
• Van der Waals Materials for Atomically-Thin Photovoltaics: Promise and Outlook
• Mobility anisotropy of two-dimensional semiconductors
• Epitaxial Growth and Band Structure of Te Film on Graphene
• Controlled Growth of a Large-Size 2D Selenium Nanosheet and Its Electronic and Optoelectronic Applications
• Effects of extrinsic point defects in phosphorene: B, C, N, O and F Adatoms
• Monolayer, Bilayer and Heterostructures of Green Phosphorene for Water Splitting and Photovoltaics
• Two-Dimensional $\beta$-PdX${}_2$ (X = S, Te) Monolayers for Efficient Solar Energy Conversion Applications
• Superior mechanical flexibility and strained-engineered direct-indirect band gap transition of green phosphorene

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