Organic Bulk-Heterojunction-Integrated Flexible Perovskite Photodetection Arrays for High-Speed Broadband Optical...

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Growing demand for self-powered, broadband photodetectors in AI, health monitoring, and optical communications.
• Limitations of conventional perovskite photodetectors, including restricted visible absorption and poor ambient stability.

Purpose of the Study:

• To develop a high-performance, self-powered, broadband photodetector using an integrated perovskite and organic bulk-heterojunction (BHJ) structure.
• To achieve enhanced photon harvesting up to 1000 nm and improve stability and flexibility.

Main Methods:

• Fabrication of a photodetector combining a perovskite (Cs_n.15FA_n.85PbI₃) absorber with an organic BHJ structure.
• Characterization of device performance, including external quantum efficiency (EQE), responsivity, response time, linear dynamic range (LDR), dark current, noise current, and specific detectivity (D*).
• Evaluation of the device's suitability for near-infrared (NIR) imaging and optical communication.

Main Results:

• Achieved peak EQE of 84% (visible) and 63% (NIR, 700-1000 nm).
• Demonstrated self-powered responsivity of 0.3 A W^-1, fast response time of 29 µs, and high LDR of 122 dB (at 900 nm).
• Suppressed dark current to 6.9 × 10^-11 A cm^-2 and noise current to 10^-14 A Hz^-1/2, resulting in D* of 10¹² Jones.
• Enabled a 25-pixel array for uniform NIR imaging and achieved low bit error rates in optical communication (90-140 kbps).

Conclusions:

• The integrated perovskite/BHJ photodetector offers a promising platform for flexible, high-speed optoelectronic applications.
• The BHJ layer significantly enhances device performance and stability.
• The developed photodetector meets the demands for advanced applications in AI, health monitoring, and optical communications.