Scientists in China have achieved a significant milestone in LED technology by developing a new type of light-emitting diode (LED) that is both highly efficient and stable.
This new hybrid LED combines the strengths of perovskite LEDs (PeLEDs) and organic LEDs (OLEDs), offering promising applications for next-generation display technologies.
One of the key goals for modern displays is to meet the Rec. 2020 color gamut standard, which ensures vibrant and accurate colors.
Perovskite LEDs have shown great potential due to their narrowband emissions and easily adjustable bandgaps, making them one of the few types of emitters capable of fully satisfying the Rec. 2020 standard.
Recent advancements have pushed the external quantum efficiency (EQE) of PeLEDs to around 30%, which is on par with commercial OLEDs.
However, the main challenge with perovskite LEDs has been their instability, which hampers their practical use in displays.
To address this issue, a team of scientists led by Professor Xuyong Yang from Shanghai University has developed a new type of LED that combines PeLED and OLED technologies into a tandem structure.
This hybrid approach leverages the high color purity of perovskites and the proven stability of OLEDs to create a superior display technology.
The secret to their success lies in the design of an efficient interconnecting layer.
This layer uses p-type interface doping, which ensures good optical and electrical coupling while reducing Joule heating, a common problem that can degrade LED performance.
This design choice significantly improves the stability and efficiency of the hybrid LED.
In practical terms, the new hybrid LED exhibits impressive performance. It has a narrow emission spectrum with a linewidth of about 30 nanometers, meaning it can produce very pure colors.
The peak luminance, or brightness, exceeds 176,000 candelas per square meter (cd/m²), which is extremely high for an LED. Most notably, the external quantum efficiency exceeds 40%, which is a remarkable achievement in the field.
Moreover, this hybrid LED has an operational half-lifetime of over 42,000 hours, meaning it can maintain its performance for a long time before its brightness drops to half of its initial value. This makes it a highly durable option for displays.
The team published their findings in the journal Light Science & Applications. Their work represents a significant step towards the commercialization of high-definition displays that meet the stringent Rec. 2020 standard. By combining the best features of PeLEDs and OLEDs, the new hybrid LED technology promises to enhance the visual experience in everything from televisions to smartphones.
In summary, this breakthrough in LED technology not only addresses the stability issues of perovskite LEDs but also enhances the overall performance and durability of display devices. The future of high-quality, vibrant displays looks brighter than ever with this innovative hybrid LED.
