A research team from Zhejiang University in China has achieved a significant advancement in LED display technology through collaboration with colleagues at the University of Cambridge in the UK. They successfully developed LEDs measuring just 90 nanometers (nm) in width using perovskite material, resulting in LED displays featuring an exceptional pixel density of up to 127,000 pixels per inch (ppi).
This development is crucial as electronic devices, such as mobile phones, increasingly demand higher pixel counts to enhance image quality. In theory, fitting more pixels into a smaller area leads to sharper images.
Currently, micro-LED technology represents the smallest pixel size available, but its development faces several challenges related to cost and efficiency. To address these issues, Baodan Zhao and her team explored perovskite—a material well-known in solar panel research. Perovskite possesses a crystalline structure, is inexpensive and straightforward to produce, and excels at absorbing and emitting light. Notably, it provides efficient charge transport, allowing for rapid conversion of electricity into light. Furthermore, perovskite is tunable, enabling researchers to adjust its composition to enhance efficiency and color.
Zhao’s team discovered that reducing pixel size did not lead to increased costs or decreased efficiency. Their results indicated that perovskite LEDs preserved remarkable brightness, unlike traditional LEDs, which often experience rapid dimming. Zhao commented, “These experiments demonstrate that at extremely small sizes, perovskite LEDs can still maintain reasonable efficiency.”
However, while the results are impressive, the current perovskite LEDs can only emit a single color. To compete with existing display technologies, the team aims to create full-color versions. They also acknowledge that the durability of these LEDs in practical applications remains to be evaluated.
Additionally, researchers caution that there is an upper limit to the detail the human eye can discern. Studies suggest that developing displays with resolutions exceeding 576 megapixels (MP) may not yield noticeable benefits, as human vision cannot perceive differences at that level.