High-performance position-sensitive detector based on the lateral photovoltaic effect in MoSe₂/p-Si junctions

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Optoelectronic position-sensitive detectors (PSDs) are crucial for detecting minute displacements.
• The lateral photovoltaic effect (LPE) is a key phenomenon enabling PSD functionality.
• Molybdenum diselenide (MoSe2) and silicon (p-Si) are promising materials for optoelectronic applications.

Purpose of the Study:

• To investigate the lateral photovoltaic effect (LPE) properties of MoSe2/p-Si heterojunctions.
• To evaluate the potential of these junctions for use in advanced position-sensitive detectors (PSDs).

Main Methods:

• Fabrication of MoSe2/p-Si heterojunctions using pulsed laser deposition.
• Characterization of the lateral photovoltaic effect (LPE) under varying laser spot positions.
• Analysis of LPE response concerning laser power and wavelength.

Main Results:

• A linear dependence of LPE on laser spot position was observed.
• MoSe2 (10 nm)/p-Si junctions demonstrated a high positional sensitivity of 563 mV/mm.
• A fast optical relaxation time of 2 μs was measured.
• The observed response is attributed to the photoelectric effect.

Conclusions:

• MoSe2/p-Si heterojunctions exhibit significant potential for optoelectronic position-sensitive detector (PSD) applications.
• The combination of high positional sensitivity and fast response time makes these junctions highly promising.
• Further research into MoSe2-based heterostructures could lead to improved PSD technologies.