Interface Engineering Sns2/Mxene Nb2c Self-Powered Photodetectors with High Responsivity and Detectivity

Abstract

Two dimensional (2D) materials and their van der Waals heterostructures (vdWHs) have stimulated worldwide research in the fields of electronics and optoelectronics. However, the construction of 2D heterostructures still remains a challenge, such as the most widely used deterministic placement method to perform 2D layers stacking often suffers from the erratic control of lattice orientation over the lattice orientations. Herein, a new 2D/2D SnS2/MXene Nb2C heterostructure for high-performance photodetectors (PDs) was designed and prepared by using a simple electrostatic assembly process. It is demonstrated that the combination of Nb2C MXene nanosheets (NSs) and SnS2 NSs significantly improve their performances of PDs by enhanced charge transfer, carrier density, light adsorption, as well as by decreasing band bending edge and charge recombination. The SnS2/Nb2C PDs obtains a remarkable responsivity (102.44 μA/W) and ultrahigh specific detectivity (7.48 × 1012 Jones) at zero external bias under 365 nm laser at level Ⅳ, respectively. Additionally, comprehensive investigations of energy level diagram derived from both experimental measurements and density functional theory calculations provide further insights of such photodetector system. This simple and reliable fabrication strategy opens a new way to large-scale production of low-cost and high-quality MXenes-based heterogeneous bonding for next-generation electronic and optoelectronic applications.

Keywords: Photodetectors, Self-powered, 2D/2D, SnS2/Nb2C