Study on Photoelectric Properties of Graphene/Molybdenum Disulfide Heterojunction

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Graphene's zero bandgap enables full spectral response in photodetectors but leads to high dark current.
• Existing graphene photodetectors face challenges with dark current and cost-effectiveness.

Purpose of the Study:

• To investigate radio frequency (RF) magnetron-sputtered molybdenum disulfide (MoS2) constructed with graphene to form heterojunctions.
• To improve dark current suppression and overall performance in graphene-based photodetectors.
• To explore the potential for low-cost and flexible photodetector applications.

Main Methods:

• Fabrication of graphene/molybdenum disulfide heterojunctions using RF magnetron sputtering.
• Characterization of the heterojunction's properties, including Schottky barrier height.
• Optimization of sputtering conditions to enhance device performance.
• Testing of photodetector performance metrics like responsivity, detectivity, and quantum efficiency.
• Evaluation of device stability on flexible substrates.

Main Results:

• The graphene/molybdenum disulfide heterojunction exhibited a Schottky barrier height of 0.739 eV, higher than graphene/Si, effectively suppressing dark current.
• Optimized sputtering conditions yielded high performance: responsivity (126 mA/W), detectivity (1.21 × 10^11 Jones), and quantum efficiency (34%).
• Graphene/molybdenum disulfide heterojunctions on flexible PET substrates demonstrated good stability.

Conclusions:

• Graphene/molybdenum disulfide heterojunctions offer a promising solution for reducing dark current in photodetectors.
• The fabricated heterojunctions exhibit excellent performance metrics and stability.
• This technology holds significant potential for developing low-cost, high-performance flexible electronic devices.