Metallic Fabry-Pérot Cavity-Enhanced "Pseudo-Charge Transfer" Absorption for Efficient Narrowband Short-Wave Infrared...

Area of Science:

• Organic electronics
• Photodetector technology
• Spectroscopy

Background:

• Narrowband organic photodetectors are crucial for SWIR applications.
• Existing spectral-narrowing methods often reduce device performance.
• Charge-transfer (CT) absorption and complex architectures limit current technologies.

Purpose of the Study:

• To engineer organic photodetectors with enhanced spectral selectivity and performance.
• To overcome limitations of existing narrowband detection strategies.
• To develop a practical design for flexible, large-area SWIR photodetectors.

Main Methods:

• Engineered a pseudo-charge-transfer state using an ultra-narrow bandgap third component.
• Optimized electrode processing to reduce parasitic absorption and interface barriers.
• Fabricated flexible photodetectors on PET substrates.

Main Results:

• Achieved spectrally selective photodetectors with EQE > 40% at 1020 nm (zero-bias).
• Demonstrated a Full Width at Half Maximum (FWHM) < 60 nm.
• Obtained detectivity > 3 × 10^13 Jones and a dynamic range > 140 dB.
• Showcased excellent mechanical stability with <5% performance degradation after 3000 bending cycles.

Conclusions:

• The co-design approach enables high-performance, spectrally selective organic photodetectors.
• The developed photodetectors offer a promising solution for wearable and large-area SWIR sensing.
• This work presents a general design paradigm for advanced organic narrowband photodetectors.