On March 21, Zhejiang University announced that its research team has successfully developed micron and nano-sized perovskite LEDs, reaching a new size limit of -90nm that is difficult for traditional LEDs to achieve, while the downsizing process only causes a slight performance loss.
The relevant research findings were published in Nature under the title "Downscaling micro- and nano-perovskite LEDs" (DOI:10.1038/s41586-025-08685-w).
Image source: Zhejiang University
In electronics science, "scale reduction" specifically refers to the process of shrinking the size of basic devices, leading to technological revolutions in fields such as computer science, information display, and human-computer interaction. Micro LED is a type of "scale-reduced" LED, which enables ultra-high-definition and ultra-high-precision optoelectronic displays by shrinking the size of LEDs.
Professor David Di, from the College of Optical Science and Engineering at Zhejiang University and the Haining International Joint College, explained, "Currently, the world's most advanced display technology is Micro LED, which is based on III-V semiconductors and is considered the 'ultimate technology' for displays."
Perovskite LEDs are a novel light source applicable to displays, lighting, and communications, offering significant advantages in color purity and color gamut. Inspired by miniaturization research on III-V semiconductor Micro LEDs several years ago, David Di's team began developing smaller perovskite LEDs for future display technologies.
After initial attempts, the team first proposed the concept of "micro-PeLED" in 2021, and subsequently obtained national and international patents.
"Miniaturizing perovskite LEDs cannot be done using Micro LED technology. Furthermore, traditional photolithography processes can damage the perovskite material," said David Di. "The simplest way to manufacture miniature perovskite LEDs is to pattern the top and bottom electrode contacts, defining the light-emitting pixel area using the overlapping area of the electrodes. However, this method exposes the perovskite material at the boundaries of the new pixels within the insulating layer."
Energy is generated by introducing it into the insulating layer. Patterned windows are etched to ensure that pixel areas are kept away from the electrode edges.
This process effectively ensures the luminous efficiency of LEDs, enabling the team to manufacture perovskite LEDs with pixel sizes ranging from hundreds of micrometers to 90 nanometers. Zhao Baodan said, "For green and near-infrared perovskite LEDs, the external quantum efficiency remains around 20% when the pixel size is in the range of hundreds of micrometers to 3.5 micrometers."
Images presented by an active-matrix micro-PeLED microdisplay (Image: Zhejiang University Optoelectronics)
The micro and nano-Pe LEDs developed by the research team have advantages over Micro LEDs based on III-V semiconductors. They only begin to show a size reduction effect at an extremely small size of about 180 nanometers, at which point the efficiency drops to 50% of its maximum value. In contrast, the efficiency of traditional Micro LEDs drops significantly when the size is below 10 micrometers.
David Di said, "The nano-PeLED shown in the paper can reach a minimum size of 90 nanometers, which is the smallest LED pixel reported to date." Based on this, the team created an LED pixel array with an ultra-high resolution of 127,000 PPI, which also set a record for the highest resolution of all types of LED arrays.
According to reports, the team, in collaboration with Hangzhou Lingzhi Technology, has created a prototype of an active-matrix micro-PeLED microdisplay driven by a TFT backplane, capable of displaying complex images and videos. They are currently actively promoting the application of this technology. (Image source: IT Home)
