Recently, Jingneng Optoelectronics successfully prepared GaN based Micro LED arrays with three primary colors of red, green, and blue on silicon substrates, marking a crucial step forward in the development of Micro LED full color chips.

The preparation of micrometer sized MicroLEDs has departed from ordinary LED processes and entered the IC process. Large scale silicon based GaN wafers have core advantages such as low cost, compatibility with IC processes, and ease of substrate stripping, making them the mainstream technology route for preparing Micro LEDs. Internationally, companies such as Aledia, Plessey, ALLOS, and StratacaCHE are all focusing on the development of Micro LEDs on silicon substrates. The major consumer electronics industry giants have invested a large amount of resources in this field, aiming to dominate the huge market for wearable devices such as AR and VR.

Micro LED is moving towards large-scale applications, requiring high yield and high luminous efficiency of red green blue three primary color Micro LED chips. At present, the GaN material systems for green and blue light have matured and meet the requirements of Micro LED process development. However, for red light Micro LEDs, the traditional red light AlInGaP system faces significant technical bottlenecks in yield and light efficiency due to its brittle material and severe non radiative recombination on the side walls. Therefore, the development of InGaN based red LEDs, especially on large-sized silicon substrates, is highly anticipated by the industry.

According to Huang Tao, the chip director of Jingneng Optoelectronics, the pixel spacing of InGaN red, green, and blue Micro LED arrays on silicon substrates reported in this report is 25 microns, with a pixel density of 1000PPI. The peak wavelengths at a current density of 10A/cm2 are 650nm, 531nm, and 445nm, respectively. The external quantum efficiency (36mil, 650nm peak wavelength) of the InGaN red light chip is 3.5%, and the half width at half height of EL is 70nm. The release of Jingneng Optoelectronics marks it as the first domestic production enterprise to achieve silicon substrate GaN based three primary color Micro LED.

The picture shows a GaN based RGB Micro LED array on silicon substrate

Vice President of Epitaxy of Jingneng Optoelectronics, stated that Jingneng Optoelectronics is the world's largest manufacturer of GaN based silicon substrate LEDs. For over a decade, Jingneng Optoelectronics has continuously introduced talents to ensure the technological upgrading and iteration of the GaN industry on silicon substrates. At present, GaN based LED products on silicon substrate of Crystal Energy Optoelectronics have covered the visible light range from 365nm to 660nm, and achieved excellent mass production yield, wavelength concentration ratio, light efficiency, and reliability. In 2018, Jingneng Optoelectronics began developing Micro LEDs on silicon substrates. Fu Yi stated that Jingneng attaches great importance to the huge application prospects of GaN based Micro LEDs on silicon substrates in the AR/VR industry, but it must continue to make efforts to solve key issues such as InGaN red light efficiency, emitting half width, and the final full color scheme. Moreover, it requires the coordination of the entire industry chain to achieve the large-scale application of Micro LED display technology.

The figure shows the normalized spectrum of GaN based RGB Micro LED on silicon substrate

The figure shows the normalized spectrum of GaN based RGB Micro LED on silicon substrate