Micro LED full color quantum dot conversion technology breakthrough

Micro LED is regarded as the next generation display technology to replace TFT-LCD and OLED display. Based on the high efficiency of LED, the ideal micro LED display has many advantages, such as high pixel, high contrast, self illumination, low energy consumption and long life.

There are still many difficulties to be overcome in the current micro LED industry, among which mass transfer is the most perplexing process for researchers and manufacturers Process), how to quickly and accurately connect the red, blue and green LED chips to the driving circuit of the panel, and how to overcome the challenges of different chip material characteristics, especially the red micro LED is fragile and other problems, so the mass transfer technology has not yet been put forward.

Professor Guo haozhong and others from Taiwan Jiaotong University, in cooperation with researchers from saplux, Yale University and Xiamen University, have made a high-color and stable micro LED array by using semi polar micro led and quantum dot photoresist technology. Relevant research results have been made by photonics Research Journal accepted and will be published soon.

Guo haozhong, the host of the research team, said that in order to reduce the number of huge transfers, the team has been focusing on the application of quantum dot Fluorescent Pink conversion technology for a long time. Only one color LED chip (blue light or near ultraviolet light) with different colors of quantum dot fluorescent powder can achieve full-color function, and the color performance of quantum dot fluorescent powder is quite outstanding.

Guo also mentioned that in addition to the challenges of huge transfer process, LED chips themselves also face many problems. For example, the blue-green LED chip will change with the operating current, resulting in the change of the color of the light, which means that when the display changes the brightness with the environmental light source, the color change may occur, which is not conducive to the use of the display, so it is necessary to solve the problem of LED chip color offset.

The team uses semi polarized epitaxy technology to make LED chips. By virtue of the characteristics of semi polarized materials, the phenomenon of wavelength shift of LED light source itself is greatly reduced, so as to overcome the problem of color shift. The second breakthrough in this research is to use quantum dot fluorescent powder photoresist technology, which mixes quantum dot fluorescent powder and photoresist liquid by special methods With the traditional micro shadow process, it can meet the needs of large-scale production of color pixels, replace the methods of red, blue and green LED chips respectively, and greatly reduce the difficulty of the transfer process.

Combined with the above two technologies, the research team has successfully realized a high color stable full-color micro LED array, and has the possibility of large-scale manufacturing, which will further the development of micro LED display technology.