News: LEDs
20 May 2025
CEA-Leti reports co-integration of GaN micro-LEDs and organic photodetectors for multi-functional display applications
At the SID Display Week 2025 conference in San Jose, CA, USA (13–15 May), micro/nanotechnology R&D center CEA-Leti of Grenoble, France presented the paper ‘Co-Integration of Organic Photodetector with MicroLED Dedicated to Multifunctional Display Application’, representing a step toward multi-functional displays that combine both display and sensing capabilities.
As the demand for innovative and interactive displays continues to grow, micro-LED technology has emerged as a promising contender for future display applications due to its exceptionally high brightness, while maintaining a minimal footprint, leaving room to integrate additional functions. These properties expand the boundaries of traditional displays by making micro-LEDs an ideal candidate for integrating both display and sensing functions. However, achieving seamless co-integration between micro-LEDs and photodetectors has remained a major technical challenge. Few studies have addressed this issue until now.
“Demonstrating the co-integration of micro-LEDs with photodetectors paves the way for multi-functional displays that combine imaging, gesture recognition, and even biometric scanning,” says Michaël Pelissier, lead author of the paper. “Micro-LED’s high radiance allows us to free up more space on the display panel to incorporate photodetectors, which not only enhances the display experience but also opens up new possibilities for smart, interactive screens.”
Picture: Next-generation multi-functional display technology (credit MELTED/CEA).
A major hurdle in integrating micro-LEDs with photodetectors is crosstalk coupling, when the light emitted by the micro-LEDs reaches the photodetector directly before reflecting off the observed scene, leading to interference and diminished sensor performance. Exploring this challenge, the paper presents key insights into how the distance between the illumination source and the photodetector affects crosstalk, providing a deeper understanding of this bottleneck.
Applications for health, security and consumer devices
CEA-Leti notes that co-integrating micro-LEDs with organic photodetectors enables promising possibilities for new applications, including:
- Fingerprint sensing across the entire display area: Enables secure access by detecting fingerprints across the entire screen and even extracts detailed images of veins, rather than in specific areas, significantly enhancing security measures for consumer devices.
- Infrared sensing for novel interface: Uses IR sensing to perform gesture recognition in close vicinity to the screen to further improve interactive capabilities.
- Bio-monitoring: Enables the extraction of physiological parameters such as heart rate, blood oxygen levels, and body temperature, supporting further advances in health and wellness applications.
As consumer devices such as smartphones and laptops become more integral to daily life, the demand for multi-functional displays continues to increase, says CEA-Leti. This co-integration allows displays that not only show content but also sense the environment, enabling smart interactions, biometrics and real-time physiological monitoring, all within a single, compact device.
Next steps
Following co-integration of the GaN micro-LEDs and organic photodetectors, CEA-Leti’s next phase of the work will focus on exploring the full potential of this technology for specific applications, such as physiological parameter tracking. The researchers also aim to investigate various photodetector technologies that can be co-integrated with micro-LEDs to optimize performance, reduce crosstalk, and further enhance multi-functionality.
