Low-Noise Electrically Modulated Dual-Mode Photodetectors with Perovskite/Organic Dual Absorption Layers.

Area of Science:

• Optoelectronics
• Materials Science

Background:

• Photodetectors with tunable spectral ranges are crucial for applications like multispectral imaging and secure communication.
• Existing technologies face limitations in spectral tunability and performance.

Purpose of the Study:

• To demonstrate a novel dual-mode photodetector with electrically tunable spectral response.
• To leverage the differing electric-field sensitivities of perovskite and organic semiconductors for dual-band detection.

Main Methods:

• Fabrication of a vertically stacked perovskite/organic dual absorption layer (FA_0.9Cs_0.1PbI_2.85Br_0.15/PM6:BTP-eC9).
• Utilizing interfacial engineering to reduce dark currents and enhance device performance.
• Characterization of photodetector performance including spectral response, dark current, detectivity, and dynamic range.

Main Results:

• Achieved a dual-mode photodetector switching between perovskite and organic absorption bands via external bias.
• Reduced dark currents by 2-3 orders of magnitude through interfacial engineering.
• Obtained high specific detectivities (>10¹¹ Jones) and large linear dynamic ranges (>190 dB) in both modes.
• Demonstrated a minimum detectable light intensity of ~7.0 pW cm^-2.
• Successfully implemented the detector in a dual-channel optical communication system for information encryption.

Conclusions:

• Perovskite/organic dual absorption layers provide a versatile platform for developing electrically modulated dual-mode photodetectors.
• This approach enables tunable spectral response ranges for advanced optoelectronic applications.
• The demonstrated device offers significant improvements in performance metrics like detectivity and dynamic range.