Enhanced Photoresponse and Wavelength Selectivity by SILAR-Coated Quantum Dots on Two-Dimensional WSe₂ Crystals

Area of Science:

• Optoelectronics and Materials Science
• Nanotechnology and Semiconductor Devices

Background:

• High-performance photodetectors are vital for photonics, imaging, spectroscopy, and data communications.
• Developing efficient, low-cost photodetectors via facile manufacturing remains a significant challenge.

Purpose of the Study:

• To synthesize novel hybrid photodetectors using a simple fabrication method.
• To investigate the performance and characteristics of CdS, CdSe, and PbS nanoparticles grown on WSe2 flakes.

Main Methods:

• Utilized the successive ionic layer adsorption and reaction (SILAR) method for nanoparticle synthesis.
• Grew CdS, CdSe, and PbS nanoparticles directly onto WSe2 crystalline flakes.
• Analyzed device performance, including photoresponsivity, quantum efficiency, and response time, alongside numerical simulations.

Main Results:

• Achieved excellent wavelength selectivity for CdS/WSe2, CdSe/WSe2, and PbS/WSe2 heterostructures.
• Demonstrated efficient photodetector performance with photoresponsivity of 48.72 A/W, quantum efficiency of 71%, and response time of 2.5-3.5 ms.
• Studied interface electric field distribution and photocarrier dynamics through simulations.

Conclusions:

• The SILAR method provides a facile route to fabricate high-performance, wavelength-tunable photodetectors.
• The hybrid photodetector architecture is compatible with semiconductor industry processes.
• This approach opens avenues for innovative optoelectronic applications.