High-Performance Gate-Voltage-Tunable Photodiodes Based on Nb₂Pd₃Se₈/WSe₂ Mixed-Dimensional Heterojunctions.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Mixed-dimensional (MD) van der Waals (vdWs) heterojunctions are crucial for photodetectors due to their unique photoelectric properties.
• Low-dimensional materials offer nanoscale thickness and vdWs contact surfaces, enhancing device performance.

Purpose of the Study:

• To propose and investigate a novel MD vdWs heterojunction for advanced photodetector applications.
• To demonstrate tunable photodetection characteristics through energy band engineering.

Main Methods:

• Fabrication of a novel MD vdWs heterojunction using one-dimensional (1D) Nb2Pd3Se8 nanowires and two-dimensional (2D) WSe2 nanosheets.
• Energy band engineering via Fermi level manipulation using gate voltage.
• Characterization of photodetection performance under laser irradiation.

Main Results:

• The Nb2Pd3Se8/WSe2 heterojunction exhibits tunable rectification characteristics with gate voltage.
• Exceptional self-powered photodetection at 685 nm with photoresponsivity of 1.45 A W-1 and detectivity of 6.8 × 10^12 Jones.
• Ultrafast response time of 37/64 μs at zero bias and broadband detection from 255 to 1064 nm.

Conclusions:

• The developed Nb2Pd3Se8/WSe2 MD heterostructures show great potential for high-performance, self-powered photodetectors.
• The gate-tunable energy band engineering offers precise control over device characteristics.
• This work paves the way for advanced electronic and optoelectronic devices.