QLEDs based on II-VI semiconductor CdSe have the advantages of high luminous efficiency, tunable luminescence color, bright colors, simple structure, and solution processability. They are strong competitors for the next generation of new displays. It has broad application prospects in the fields of domain, flexible, printed display and so on. To achieve a full-color QLED display, the quantum dot light-emitting layer must be finely patterned to form an array of red, green, and blue QLED pixels arranged side-by-side.

The technologies that have been developed at present, such as inkjet printing, stamp transfer, lithography, etc., can directly pattern quantum dots, and directly perform "surgery" on the luminescent layer of quantum dots, cutting them into the shape of a lattice," "Surgery" operation steps are complicated, and in the process of multiple (usually 3 times, to form red, green, and blue pixels) "surgery", quantum dots will inevitably be destroyed, so that the performance of the resulting QLED is lower than that without " Surgery" QLED. Therefore, in order to meet the needs of high-resolution, high-performance displays, further research is needed on patterning techniques that do not damage the light-emitting layer of quantum dots.

In order to achieve ultra-high-resolution, high-performance full-color QLED display, Chen Shuming's research group proposed a realization method of full-color QLED display based on microcavity light field control technology. By using white light QLED as a carrier and introducing an optical resonant cavity into the device, the red, green and blue resonant cavities are used to convert white light into red, green and blue monochromatic light respectively, avoiding the direct patterning of quantum dots from the source. damage to come. By studying the exciton energy transfer mechanism of white light QLED and the spectral modulation mechanism of white light QLED by microcavity under the action of microcavity light field, a low-loss quantum dot color conversion microcavity can be realized; Color filters, high-resolution, high-efficiency, wide-color gamut, low-cost, and simple-process full-color QLED display without the need for patterned quantum dots.

IZO (indium zinc oxide) is used as a transparent phase adjustment layer. By adjusting the thickness of IZO to satisfy the resonance conditions of red, green and blue light emission, the corresponding cavity can selectively convert the white light emitted by the quantum dot light-emitting layer into red, green and blue light, respectively. Green and blue light. In this structure, a high-resolution red, green, and blue QLED pixel array can be obtained only by patterning the IZO using mature photolithography techniques. By optimizing the thickness of the IZO phase adjustment layer, the optimal IZO thicknesses are 50 (blue light), 90 (green light) and 130 nm (red light).