Tunable Structural, Electronic, and Optical Properties of Layered Two-Dimensional C₂N and MoS₂ van der Waals Heterostructure as Photovoltaic Material

TLDR

The nitrogenated porous 2D material C₂N has been synthesized via a simple wet‑chemical reaction, offering novel electronic and optical properties. This study aims to investigate the structural, electronic, and optical characteristics of the layered C₂N/MoS₂ van der Waals heterojunction. Density functional theory calculations were employed to analyze the heterojunction’s properties. DFT results show that the C₂N/MoS₂ heterojunction has a 1.30 eV direct band gap, type‑II band alignment, efficient charge‑carrier separation, enhanced visible‑light absorption, strain‑tunable electronic and optical behavior, and thus represents a promising photovoltaic material.

Abstract

The nitrogenated porous two-dimensional (2D) material C2N has been successfully synthesized using a simple wet-chemical reaction, which provides a high-performance way to produce such 2D materials with novel electronic and optical properties. In this work, density functional theory (DFT) calculations were performed to investigate the structural, electronic, and optical properties of the layered C2N/MoS2 van der Waals (vdW) heterojunction. The C2N/MoS2 heterojunction was found to have a direct band gap of 1.30 eV and to present the typical type-II heterojunction feature, facilitating the effective separation of photogenerated electrons and holes. The calculated band alignment and enhanced optical absorption suggest that the C2N/MoS2 heterojunction should exhibit good light-harvesting properties. The vertical strain can effectively tune the electronic properties and optical absorption of the C2N/MoS2 heterojunction by changing the interaction between the pz orbital of C2N and the dz2 orbital of MoS2. The moderate band gap, well-separated photogenerated electrons and holes, and enhanced visible-light absorption indicate that the C2N/MoS2 heterojunction is a potential photovoltaic structure for solar energy.