Large Lateral Photovoltaic Effect in MoS₂/GaAs Heterojunction

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanotechnology

Background:

• Molybdenum disulfide (MoS2) is a promising 2D material with unique electronic properties.
• Gallium arsenide (GaAs) is a widely used semiconductor material in optoelectronics.
• Heterojunctions formed by combining different semiconductor materials can exhibit novel functionalities.

Purpose of the Study:

• To investigate the lateral photovoltaic effect (LPE) in MoS2/GaAs heterojunctions.
• To compare the LPE in MoS2/n-GaAs and MoS2/p-GaAs heterojunctions.
• To explore the potential applications of these heterojunctions in position-sensitive detectors.

Main Methods:

• Fabrication of MoS2/GaAs heterojunctions using magnetron sputtering.
• Characterization of the lateral photovoltaic effect (LPE) under laser illumination.
• Analysis of energy-band alignment to understand LPE mechanisms.

Main Results:

• A significant LPE was observed in MoS2/n-GaAs heterojunctions.
• The LPE showed a linear dependence on laser illumination position with high sensitivity (416.4 mV/mm).
• MoS2/p-GaAs heterojunctions exhibited a much weaker LPE.

Conclusions:

• MoS2/n-GaAs heterojunctions demonstrate excellent LPE characteristics.
• The findings suggest MoS2/GaAs heterojunctions are suitable for high-performance position-sensitive detectors.
• Understanding energy-band alignment is crucial for optimizing LPE in such devices.