Bias-Switchable Dual-Mode Organic Photodetector with High Operational Stability Using Self-Trapped Cs₃Cu₂I₅...

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Conventional photovoltaic (PV) photodetectors struggle with faint signals.
• Photomultiplication (PM) devices detect weak light but degrade under strong light and high bias.
• There is a need for integrated systems with both PV and PM modes.

Purpose of the Study:

• To develop highly efficient organic photodetectors with bias-switchable dual PV and PM operation modes.
• To utilize lead-free Cs3Cu2I5 nanocrystals with self-trapping exciton nature.
• To create a scalable and convenient production process for multi-functional optoelectrical applications.

Main Methods:

• Integration of lead-free Cs3Cu2I5 nanocrystals as an interfacial layer.
• Fabrication of a bulk and layer-by-layer heterojunction structure.
• Demonstration of bias-switchable dual-mode operation.

Main Results:

• The fabricated device operates at low bias (0 V for PV, 0.8 V for PM).
• Achieved high specific detectivity (~10^13 Jones) and fast response speed (1.59 μs).
• Exhibited a large bandwidth (>0.2 MHz) and long-term stability (4 months).

Conclusions:

• The Cs3Cu2I5 nanocrystal strategy enables bias-switchable dual-mode photodetectors.
• This approach provides a convenient and scalable method for developing advanced organic optoelectrical devices.
• The synergy strategy is validated across different materials and architectures.