Non-shielding thin film transistor, array substrate and display device

Abstract

The invention relates to the technical field of thin-film transistors and provides a non-shading type thin-film transistor, an array substrate comprising the same and a display device. The non-shading type thin-film transistor is of a non-shading type bottom-gate structure, and an active source consists of a microcrystalline-silicon active layer and an amorphous-silicon active layer, wherein the microcrystalline-silicon active layer is arranged above a gate insulating layer, and the two areas corresponding to a source electrode and a drain electrode extend out of a grid electrode respectively; the amorphous-silicon active layer exists only between the source electrode and the drain electrode shielded by the gate electrode; the thickness of thin films of the two active layers can be freely distributed, the microcrystalline-silicon active layer can be arranged as thin as possible and the amorphous-silicon active layer can be relatively thick. Therefore, the non-shading type thin-film transistor, the array substrate and the display device provided by the invention have the advantages that rise of off-state current caused under backlight illumination can be effectively inhibited, the migration rate and the on-state current of the TFT (Thin-Film Transistor) devices can be increased and the ratio between the on-state current and the off-state current is increased.

Description

technical field [0001] The invention relates to the technical field of thin film transistors, and in particular provides a non-light-shielding thin film transistor, an array substrate and a display device. Background technique [0002] Such as figure 1 As shown, the leakage current conduction mechanism of the thin film transistor (Thin Film Transistor, TFT) itself is mainly the hole current formed by channel thermionic emission, and the leakage current generated under the light. In the working environment of a thin film transistor device, there are both light from the backlight passing through the substrate 1 and light from the outside, and the resulting reflected light and stray light form photogenerated carriers in the active layer 4, that is, electrons - hole pairs, under the action of an external electric field, electrons move toward the drain 7, and holes move toward the source 6, thereby forming a hole leakage current. In the TFT-LCD, the metal grid 2 of the bottom g...

AI Technical Summary

Problems solved by technology

The active layer 4 on the source 6 and drain 7 sides of the non-light-shielding structure TFT protrudes from the gate 2. In the off state of the TFT, the source 6, the drain 7 and the gate 2 are separated by N + Microcrystalline silicon layer 5, active layer 4, hole accumulation layer, gate insulating layer 3, hole accumulation layer and N on the channel + A PN junction is formed between the microcrystalline silicon layers 5, so that the current can only flow from the hole accumulation layer to the outside, but not from the outside to the inside, which can effectively reduce the output efficiency of holes, but since the active layer 4 extends out of the gate 2. The illuminated area of ​​the active layer 4 is greatly increased, which increases the illumination leakage current

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