A pixel unit and its preparation method, array substrate and display device

Abstract

The present invention provides a pixel unit. The pixel unit includes: a pixel defining layer, a pixel electrode, a light-emitting layer and a common electrode. The pixel electrode includes a bottom surface and a side surface, and the side surface extends along the side wall of the second via hole to the second via hole. On the top of the side wall, the light emitting layer is formed on the pixel electrode and covers the pixel defining layer, and the common electrode is formed on the light emitting layer, covering the light emitting layer and extending along the top surface of the pixel defining layer. The pixel unit of the present invention greatly reduces the light scattered from the light-emitting layer to the surroundings, greatly improves the color mixing phenomenon between the pixel units, effectively solves the color mixing problem caused by light scattering, increases the light-emitting area of ​​the pixel unit, and improves the The overall brightness reduces the cost of the mask and greatly reduces the cost of the entire process, improves the production capacity, and improves the luminous effect.

Description

technical field [0001] The present invention relates to the field of technical display technology, in particular to a pixel unit of an organic light emitting diode display device, a manufacturing method thereof, an array substrate and a display device. Background technique [0002] Organic light-emitting diode display device (OLED) is a new type of light-emitting technology, which uses stimulated radiation of organic substances to emit light. OLED drive methods are divided into active drive and passive drive. The active drive uses thin-film transistors (TFT) as The driving device, the pixel unit is driven by the corresponding TFT to form a TFT driving array, wherein the OLED driven by low-temperature polysilicon thin-film transistor (LTPS-TFT) 100 has faster electron transfer rate, smaller thin-film circuit area, higher resolution and structure The advantages of simplicity and high stability, the pixel unit of the low-temperature polysilicon thin-film transistor organic ligh...

AI Technical Summary

Problems solved by technology

[0002] Organic light-emitting diode display device (OLED) is a new type of light-emitting technology, which uses stimulated radiation of organic matter to emit light. OLED drive methods are divided into active drive and passive drive. The active drive uses thin-film transistors (TFT) as The driving device, the pixel unit is driven by the corresponding TFT to form a TFT driving array, wherein the OLED driven by low-temperature polysilicon thin-film transistor (LTPS-TFT) 100 has faster electron transfer rate, smaller thin-film circuit area, higher resolution and structure The advantages of simplicity and high stability, the pixel unit of the low-temperature polysilicon thin-film transistor organic light-emitting diode (LTPS-TFT OLED) display device in the prior art is as follows figure 1 As shown, the pixel unit generally includes a low-temperature polysilicon thin film transistor as a driving thin film transistor 100, a planarization layer 200, a pixel definition layer 300, a pixel electrode 400, a light emitting layer 500, and a common electrode 600. The two sides of the light emitting layer 500 are directly When in contact with the pixel defining layer 300, the light emitted by the light emitting layer 500 will be scattered to the surrounding through the pixel defining layer 300, and will mix with the scattered light of other pixel units around it, seriously affecting the display effect. contact, the light-emitting area is limited, affecting the overall brightness

Additionally, if figure 1 The process flow of the pixel unit shown is generally polysilicon (Poly)-gate insulating layer (Gate1)-gate (Gate2)-interlayer deposition layer (ILD)-source, drain (SD)-planarization layer ( PLN)-pixel electrode (Anode)-pixel definition layer (PDL)-pad spacer (PS)-light-emitting layer evaporation (EL)-common electrode (Vcom), this process requires two processes to prepare flat layer via holes and The pixel defining layer 300 requires two sets of mask plates, the process is more complicated and the cost is higher, and the method of forming the pixel electrode 400 first and then forming the pixel defining layer 300 will make the pixel electrode material after the process of forming the pixel defining layer 300 Residues pollute the pixel electrode 400, thereby affecting the luminous effect. Therefore, there is an urgent need in the art for a pixel unit that can avoid color mixing and a method for preparing a pixel electrode that is simple in process, relatively low in cost, and does not affect the luminous effect.

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