Organic Thin Film Transistor Adhesive Layer Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing organic thin film transistors face issues with the growth of organic semiconductor layers on hydrophilic gate insulation layers, resulting in smaller grain sizes and increased grain boundaries, which deteriorate the electric properties due to charge trapping.

Innovation Solution

The introduction of a hydrophilic adhesive layer between the gate insulation layer and the source/drain electrodes, and a hydrophobic adhesive layer between the organic semiconductor layer and the gate insulation layer, formed through plasma treatments, improves the adhesive properties and grain size of the organic semiconductor layer, reducing charge trap sites and enhancing electric performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the gate insulation layer is treated with plasma to improve adhesive strength, then the adhesive strength between the gate insulation layer and source/drain electrodes is improved, but the organic semiconductor layer grows with small grains and grain boundaries increase

Engineering Contradiction:

Improveadhesive strengthVSAvoidgrain size

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The gate insulation layer is divided into two distinct regions: a first gate insulation layer treated with plasma to provide hydrophilic properties for strong adhesion to source/drain electrodes, and a second gate insulation layer not treated with plasma to provide hydrophobic properties for large grain growth of the organic semiconductor layer. This segmentation allows each region to fulfill its specific function without compromise.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the gate insulation layer are given different local properties: the region contacting source/drain electrodes has hydrophilic characteristics for maximum adhesive strength, while the region contacting the organic semiconductor layer has hydrophobic characteristics to promote large grain formation. This local differentiation resolves the contradiction between adhesion and grain growth.

Inventive Principle:

Principle #3Local quality

2Strength

If the organic semiconductor layer is formed on the hydrophilic gate insulation layer, then the adhesive strength is improved, but the grain boundaries increase in number and electric properties deteriorate

Engineering Contradiction:

Improveadhesive strengthVSAvoidelectric properties

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The gate insulation layer is segmented into two functional zones: a first zone with plasma treatment providing hydrophilic surface for strong electrode adhesion, and a second zone without plasma treatment providing hydrophobic surface for high-quality organic semiconductor growth with minimal grain boundaries, thus maintaining both adhesion strength and electric properties.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The dual-region gate insulation layer acts as an intermediary structure that mediates between the requirements of the source/drain electrodes (needing hydrophilic surface for adhesion) and the organic semiconductor layer (needing hydrophobic surface for large grain growth). Each region of the gate insulation layer provides the appropriate surface properties for the material it contacts.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The use of hydrophilic and hydrophobic adhesive layers increases the grain size of the organic semiconductor layer, thereby improving its electric properties by reducing grain boundaries that act as charge traps, leading to better performance in organic thin film transistors.

Implementation Method 1

The gate insulation layer 53 of the organic material is treated with plasma to improve an adhesive strength between the gate insulation layer 53 of the organic material and the source/drain electrodes 55a/55b of the metal material.

Methodology Applied

Scientific EffectPlasma treatment: Plasma

Implementation Method 2

the gate insulation layer treated with plasma has hydrophilic properties

Methodology Applied

Scientific EffectHydrophilic properties: Hydrophile

Implementation Method 3

a second adhesive layer having hydrophobic properties formed between the organic semiconductor layer and the gate insulation layer

Methodology Applied

Scientific EffectHydrophobic properties: Hydrophobe

Data Source

PatentUS9224965B2Organic thin film transistor and method for manufacturing the same

Publication Date: 2015.12.29 LG DISPLAY CO LTD

AI summary

An organic thin film transistor and a method for manufacturing the same is disclosed, which can improve the device properties by decreasing a contact resistance which occurs in a contact area between an organic semiconductor layer and source/drain electrodes. The organic thin film transistor includes a gate electrode formed on a substrate, a gate insulation layer formed on the gate electrode, source and drain electrodes overlapped with both edges of the gate electrode and formed on the gate insulation layer, an organic semiconductor layer formed on the gate insulation layer including the source/drain electrodes, a first adhesive layer having hydrophilic properties formed between the gate insulation layer and the source/drain electrodes, and a second adhesive layer having hydrophobic properties formed between the organic semiconductor layer and the gate insulation layer.