Organic Upconversion Devices for Infrared Photodetection

Organic upconversion devices integrate an organic infrared photodetector with an organic light-emitting diode in a monolithic structure, enabling direct conversion of low-energy infrared photons into high-energy visible light. This approach offers a pixel-free, solution-processable route to infrared imaging, combining mechanical flexibility, large-area coverage and low fabrication cost. Key figures of merit include photon-to-photon conversion efficiency, spectral selectivity across near-infrared (NIR) and short-wave infrared (SWIR) bands, response speed and dark luminance. Recent developments have addressed charge-generation architectures, interfacial engineering and emitter design to enhance external quantum efficiency and spatial resolution. Applications span biomedical imaging, wearable electronics, night vision and environmental sensing, with growing emphasis on real-time signal processing and high-contrast imaging in low-light conditions.

Research from Nature Portfolio

Researchers have demonstrated a cathodic-controlled organic upconverter designed to map local blood vessels by converting NIR images into visible emissions. The device employs a multilayer photosensitive charge-generation layer coupled to a phosphorescent organic light-emitting diode, achieving a spatial resolution of 600 dpi and a conversion efficiency exceeding 3 %. Temperature-dependent electrical analyses revealed that interfacial barrier reduction at the cathode enhances charge injection and dissociation, enabling high-contrast imaging under low operating voltages.

An integrated mid-infrared to visible upconversion chip has been introduced, combining quantum dot photodetectors based on nanocrystalline PbSe with an NPN bipolar junction transistor and a doped phosphorescent OLED. The architecture converts mid-infrared light (3–5 µm) into green emission at 523 nm with an external quantum efficiency surpassing conventional benchmarks. By tuning the quantum dot absorption edge and leveraging transistor current gain, the system offers a flexible platform for wavelength agility and high-efficiency mid-infrared detection in compact optoelectronic circuits.

Organic Upconversion Devices for Infrared Photodetection publication trend

The graph below shows the total number of articles in organic upconversion devices for infrared photodetection across all publications each year (not limited to Nature Index journals).

Technical terms

Organic upconversion device (OUC): A monolithic system combining an organic photodetector and an organic light-emitting diode to convert infrared photons into visible light.

Charge-generation layer (CGL): The photosensitive material layer in an OUC where incident infrared photons generate charge carriers.

Bulk heterojunction: A blend of donor and acceptor organic semiconductors forming an interpenetrating network for efficient charge separation in photodetectors.

External quantum efficiency (EQE): The ratio of emitted or collected photons to incident photons, indicating the efficiency of photonic conversion in optoelectronic devices.

Near-infrared (NIR): The portion of the infrared spectrum from approximately 750 nm to 1 400 nm used in imaging and sensing applications.

References

1. Semi‐Transparent, Pixel‐Free Upconversion Goggles with Dual Audio‐Visual Communication. Advanced Science (2023).
2. Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices. Science and Technology of Advanced Materials (2021).
3. On the Response Speed of Narrowband Organic Optical Upconversion Devices. Advanced Optical Materials (2022).
4. Cathodic-controlled and near-infrared organic upconverter for local blood vessels mapping. Scientific Reports (2016).
5. Ultra High-efficiency Integrated Mid Infrared to Visible Up-conversion System. Scientific Reports (2020).