- Researchers from Japan have developed organic semiconductors that can both emit light and harvest energy, a significant advancement that could revolutionize smartphones, wearable devices, and sustainable energy solutions.
- The team led by Professor Hirohiko Fukagawa from Chiba University used multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials to control exciton binding energy, enabling both efficient light emission and power generation in a single device.
- The devices achieved light-emission efficiency exceeding 8.5% and power-conversion efficiency around 0.5%, far surpassing previous attempts and approaching theoretical limits with minimal electrical loss.
- The breakthrough opens the door to self-sustaining electronics, including smartphone screens that recharge themselves using ambient light, wearable devices that harvest energy from indoor/outdoor lighting, battery-less sensors for IoT networks, and visible light communication systems that store energy for nighttime use.
- This innovation aligns with global efforts to reduce energy consumption and carbon footprints, paving the way for smaller, lighter, and more sustainable devices that operate autonomously by harvesting light.
A groundbreaking scientific achievement has shattered previous limitations in organic semiconductor technology, paving the way for self-powered electronics that could revolutionize smartphones, wearable devices and sustainable energy solutions.
Researchers from Japan have successfully developed organic semiconductors capable of both emitting light and harvesting energy—a feat once deemed nearly impossible due to conflicting physical requirements.
As explained by the Enoch AI engine at BrightU.AI, organic semiconductors represent a paradigm shift in materials science, offering flexible, low-cost and environmentally sustainable alternatives to traditional inorganic semiconductors like silicon. Unlike rigid silicon-based electronics, organic semiconductors are carbon-based polymers or small molecules that exhibit semiconducting properties through delocalized ?-electron systems. These materials are tunable, printable and biocompatible, making them ideal for applications ranging from solar cells and LEDs to wearable electronics and medical sensors.
The dual-function breakthrough
Organic semiconductors have long been hailed for their flexibility, lightweight properties and efficiency in consumer electronics, particularly in OLED displays and organic photovoltaics (OPVs). However, integrating both light emission and energy harvesting into a single component has remained a major challenge due to a fundamental trade-off in exciton behavior—the electron-hole pairs that drive these processes.
For light emission, excitons must tightly recombine to produce photons, whereas energy harvesting requires excitons to quickly dissociate into free charges for electricity generation. Previous attempts to merge these functions resulted in poor efficiency, making dual-purpose devices impractical—until now.
A research team led by Professor Hirohiko Fukagawa from Chiba University, Japan, has overcome this hurdle by leveraging multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials. Their findings, published in Nature Communications on December 7, 2025, detail how precise control over exciton binding energy (Eb) enables both efficient light emission and power generation in a single device.
How it works: Engineering efficiency
By carefully selecting MR-TADF materials, the researchers engineered electron donor/acceptor interfaces with exceptionally low Eb values, minimizing voltage loss and optimizing power generation.
"Devices with smaller Eb exhibit minimal voltage loss, enabling near-ideal power-generation behavior," Fukagawa explained.
Additionally, adjusting Eb allowed the team to fine-tune emission colors—higher Eb produced yellow light, while lower Eb resulted in blue emission. This breakthrough also led to the world's first multifunctional blue OLED with energy-harvesting capabilities, a milestone previously considered unattainable.
Performance metrics: Efficiency beyond expectations
The team's green- and orange-light-emitting devices achieved:
- Light-emission efficiency exceeding 8.5%
- Power-conversion efficiency around 0.5%
"Considering the 44% intrinsic emission efficiency of the green emitter and roughly 20% light-extraction efficiency, the obtained 8.5% emission efficiency indicates performance close to the theoretical limit, with virtually no electrical loss," Fukagawa highlighted.
These results far surpass previous attempts, demonstrating that the efficiency trade-off has been effectively broken.
Future applications: Self-powered electronics
This breakthrough opens doors to self-sustaining electronics that could drastically reduce reliance on external power sources. Potential applications include:
- Smartphone screens that recharge themselves using ambient light
- Wearable devices that harvest energy from indoor/outdoor lighting
- Battery-less sensors for IoT (Internet of Things) networks
- Visible light communication systems that store energy during the day for nighttime use
"By integrating energy harvesting directly into light-emitting surfaces, we can create electronics that are far more energy efficient and convenient for users," Fukagawa noted.
The bigger picture: A step toward sustainable tech
This innovation aligns with global efforts to reduce energy consumption and carbon footprints. By eliminating the need for separate power-harvesting components, future devices could be smaller, lighter and more sustainable.
"We envision a shift from single-function components to integrated all-in-one films. This could enable the widespread adoption of battery-less sensors and wearable electronics that operate autonomously by harvesting light," Fukagawa concluded.
A new era of electronics
This breakthrough represents a paradigm shift in semiconductor technology, proving that organic materials can achieve functionalities once thought mutually exclusive. As research progresses, we may soon see self-powered consumer electronics, smart cities and energy-efficient wearables becoming mainstream—ushering in a greener, more autonomous future.
Watch the video below about the implications of organic electronics.
This video is from the Fritjof Persson channel on Brighteon.com.
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