Aqueous-Phase Formation of Two-Dimensional PbI₂ Nanoplates for High-Performance Self-Powered Photodetectors

Area of Science:

• Materials Science
• Nanotechnology
• Green Chemistry

Background:

• Aqueous synthesis of nanomaterials offers a sustainable alternative to organic solvents.
• Nanostructures fabricated in water show promise for advanced optoelectronic devices.
• Lead iodide (PbI2) nanostructures are of interest for photodetector applications.

Purpose of the Study:

• To synthesize lead iodide (PbI2) nanoplates using an environmentally friendly aqueous method.
• To fabricate and characterize a planar photodetector based on these PbI2 nanoplates.
• To evaluate the performance of the photodetector, particularly in self-powered mode.

Main Methods:

• Aqueous-phase synthesis of lead iodide (PbI2) nanoplates.
• Fabrication of a planar photodetector with the structure ITO/PbI2 NPs/Au.
• Performance characterization including photosensitivity, photoresponsivity, and response times.
• Analytical calculations for key parameters at zero bias.

Main Results:

• The ITO/PbI2 NPs/Au photodetector exhibited high photosensitivity (3.9 × 10^3) and photoresponsivity (0.51 mA/W at 405 nm).
• Self-powered operation demonstrated a significant on-off ratio (10^3) and specific detectivity (3.3 × 10^11 Jones).
• The device showed a photo-response at 0 V bias with rise/decay times of approximately 1 s, and rapid response (0.23/0.38 s) at -5 V.

Conclusions:

• Aqueous synthesis is a viable route for producing PbI2 nanostructures for optoelectronics.
• The fabricated photodetector demonstrates high performance and self-powered capabilities.
• This work facilitates large-area fabrication of efficient photodetectors using sustainable methods.