Engineered PN MoS₂-Al₂O₃-Based Photodiode Device for High-Performance NIR LiDAR and Sensing Applications.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Devices

Background:

• Near-infrared (NIR) photodetectors are crucial for technologies like LiDAR and optical communications.
• Existing devices often face limitations in response speed and power efficiency.

Purpose of the Study:

• To develop an enhanced NIR photodetector with improved performance for LiDAR and environmental sensing.
• To investigate the effect of a co-sputtered MoS2-Al2O3 composite layer on photodiode characteristics.

Main Methods:

• Fabrication of a PN photodiode incorporating a co-sputtered MoS2-Al2O3 composite layer.
• Characterization of the photodiode's performance under NIR illumination, including photocurrent, response time, and spectral responsivity.
• Comparison with a reference device without the composite layer.

Main Results:

• The MoS2-Al2O3 composite photodiode achieved a photocurrent of 10 mA at 4 V under 100 mW·cm-2 illumination.
• A significant threefold (approx. 300%) improvement in performance was observed compared to the reference structure.
• The device exhibited peak responsivity at 970 nm and sensitivity up to 1100 nm, with a response time of 155 µs.

Conclusions:

• The co-sputtered MoS2-Al2O3 composite layer effectively passivates defects and enhances carrier transport, improving the MoS2/Si interface.
• The composite layer facilitates infrared photon absorption and improves carrier collection, reducing recombination.
• The developed photodiode architecture is low-cost, broadband, and suitable for eye-safe LiDAR and environmental monitoring.