MXene/RGO/Si Schottky Junction for a High-Performance Self-Powered Broadband Photodetector

Area of Science:

• Materials Science
• Nanotechnology
• Device Physics

Background:

• Two-dimensional (2D) materials offer potential for self-powered photodetectors but face challenges like interface instability and poor durability.
• Ti3C2Tx-MXene provides high conductivity but is prone to oxidation, while reduced graphene oxide (RGO) offers robustness but limited charge transport.

Purpose of the Study:

• To develop a stable and high-performance self-powered photodetector using a hybrid interfacial engineering strategy.
• To address the performance-stability trade-off in silicon (Si)-based Schottky photodetectors.

Main Methods:

• Fabrication of a Ti3C2Tx-MXene/RGO/Si Schottky junction photodetector.
• Integration of Ti3C2Tx-MXene and RGO as a multifunctional Schottky-contact layer.
• Characterization of device performance, including on/off ratio, responsivity, specific detectivity, and response times.

Main Results:

• The Ti3C2Tx-MXene/RGO/Si photodetector demonstrated significantly enhanced zero-bias performance compared to Ti3C2Tx-MXene/Si devices.
• Achieved an on/off ratio of 1.48 × 10^3, responsivity of 1.82 × 10^2 mA W^-1, and specific detectivity of 2.37 × 10^10 Jones at 368 nm.
• Reduced rise and fall times to 12 ms and 18 ms, respectively, with improved operational stability under ambient conditions.

Conclusions:

• The Ti3C2Tx-MXene/RGO hybrid interface effectively promotes carrier extraction, suppresses dark current, and enhances device stability.
• This hybrid interfacial engineering strategy is a viable approach for advancing Si-based self-powered Schottky photodetectors.