Pixel defining layer and its preparation method and application

Abstract

The invention relates to a pixel defining layer and its preparation method and application. The pixel defining layer includes a first pixel defining layer and a second pixel defining layer stacked on the first pixel defining layer; the first pixel defining layer is provided with a plurality of pixels corresponding to the light emitting regions of each sub-pixel unit. a first window opening area, the second pixel defining layer is provided with a second window opening area corresponding to the first window opening area; the area of ​​the second window opening area is larger than that of the first window opening area area, and there is a distance between the edge of the second window opening area and the edge of the first window opening area. The above-mentioned pixel defining layer can avoid the problem of "cathode disconnection", improve the printing resolution, improve the uniformity of the printing film and reduce the leakage current.

Description

technical field [0001] The invention relates to the technical field of electroluminescence, in particular to a pixel defining layer and its preparation method and application. Background technique [0002] OLED is a new third-generation flat-panel display technology. Compared with the current mainstream LCD, OLED has the characteristics of active light emission, simple structure, wide viewing angle, fast response, energy saving, light and thin, and bendable, and has been widely researched and applied. At present, the commercial application of OLED mainly adopts evaporation technology, but evaporation requires relatively expensive vacuum equipment, the utilization rate of materials is low, and its production cost is relatively high, so it is at a disadvantage in market price competition. Solution processing technology, especially inkjet printing technology has the advantages of simple operation, non-contact, no mask, low equipment cost, high material utilization rate, etc., a...

AI Technical Summary

Problems solved by technology

In order to solve the resolution problem, it is generally necessary to perform hydrophobic treatment on the surface of the pixel-defining layer, so that the hydrophilic ink will not easily spread on the hydrophobic pixel-defining layer and roll into the pixel pit; but it will be hydrophilic when spreading in the pixel Poor wettability between the non-toxic ink and the hydrophobic pixel-defining layer results in a gap between the organic light-emitting material and the edge of the pixel pit, which easily causes a short circuit between the cathode and the anode of the device, resulting in a large leakage current, such as figure 1 shown

In order to improve the wettability of the ink in the pixel, the lower part of the pixel defining layer is usually subjected to hydrophilic treatment, so that when the ink spreads, the pixel defining layer changes from a non-wetting state to a wetting state, which can suppress the generation of leakage current, but It also accelerates the pinning of the three-phase line of the ink and intensifies the formation of "coffee rings", resulting in a decrease in the uniformity of the film, such as figure 2 shown

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