Core-based high-efficiency pure red light quantum dot chip has been achieved, and QD-Mini LED is abo

Based on traditional color conversion LED devices, the color gamut is limited to about 90% NTSC, and the display effect has been difficult to further break through. LED devices made of new luminescent materials such as quantum dots can achieve narrow emission half-wave widths (<20 nm) in the red, blue and green bands through the color conversion process, and the color gamut can exceed 120% NTSC. It is regarded as the next generation. One of the most promising display technologies. However, at present, quantum dot LED devices still lack effective packaging design, and traditional packaging structures are still widely used in color conversion structures and chip integration, thus limiting the improvement of device luminous efficiency and stability.

On July 5, 2023, Shanghai Xinyuanji Semiconductor adopted chemical lift-off GaN technology and achieved high-yield, high-efficiency pure red flip-chip structure and form-up structure quantum dot Miniled chip through specially designed optical reflective layer and quantum dot color conversion technology. This major technological breakthrough will effectively reduce the cost of red light chips, improve the cost performance of products, or comprehensively accelerate the commercialization process of quantum dot display technology.

Figure 1: Structural schematic diagram

In terms of flip-chip quantum dot chip technology, the core element base will attach the light emitting surface of the stripped GaN chip to the processed special optical reflective layer substrate with quantum dot glue. The optical reflective layer has high reflectivity for the wavelength of the excitation light source and very high transmittance for the wavelength band where the quantum dot emits light, so as to achieve better excitation of red quantum dots. When the thickness of red quantum dots is less than 1 micron, after the quantum dots are fully excited, The red light chip does not leak blue light and other phenomena. During the processing of quantum dot chips, we adopt standard semiconductor processes, combined with the photomask alignment method, and make a high-density dielectric layer on the sidewalls of the pixels to achieve complete sealing of quantum dots and solve the concerns of quantum dots in terms of reliability.

Figure 2: Optical Reflection Layer Design

The characteristic curve of the product is as follows: (Chip size: 2* 4mil/50* 100um) Characteristic curve:

Forward Voltage Vs Forward current

Forward current Vs Relative Luminous Intensity

Forward current Vs Dominant Wavelength

The luminescence status and yield of the product are as follows: Table 1: Luminescence test status and yield:

Schematic diagram of chip illumination

Flip-chip quantum dot MiniLED-Front illuminated image

Flip-chip quantum dot MiniLED -black illuminated image

Spectral distribution: no blue peak

Chip leakage distribution: IR<0.1uA, yield greater than 97%

chip voltage distribution: