Large Area Vertically Oriented Few-Layer MoS₂ for Efficient Thermal Conduction and Optoelectronic Applications

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Molybdenum disulfide (MoS₂) is a promising 2D material for optoelectronics.
• Large-area synthesis of MoS₂ with controlled morphology is crucial for device applications.
• Vertically oriented MoS₂ offers unique advantages for light-matter interactions.

Purpose of the Study:

• To grow large-area vertically oriented few-layer MoS₂ (VFL MoS₂) on a p-type Si substrate.
• To characterize the thermal conductivity of VFL MoS₂.
• To investigate the optoelectronic performance of VFL MoS₂/Si heterostructures.

Main Methods:

• Chemical Vapor Deposition (CVD) for VFL MoS₂ growth.
• Optothermal Raman spectroscopy for thermal conductivity measurement.
• Photoluminescence spectroscopy and Density Functional Theory (DFT) for electronic property analysis.
• Fabrication and characterization of VFL MoS₂/Si photodiodes.

Main Results:

• Successful growth of 1 × 1 cm² VFL MoS₂ on p-type Si.
• Measured thermal conductivity of VFL MoS₂ as 100 ± 14 W m^-1 K^-1 at room temperature.
• Confirmed semiconducting behavior of VFL MoS₂.
• Achieved high photoresponsivity of 7.37 A W^-1 in VFL MoS₂/Si photodiodes.

Conclusions:

• VFL MoS₂ exhibits excellent thermal conductivity due to reduced phonon-defect scattering.
• The VFL MoS₂/Si photodiode demonstrates superior optoelectronic performance.
• Vertical orientation enhances light trapping and charge separation, benefiting optoelectronic device applications.