Lanthanum Boride TFT Active Layer for Indium-Free Displays

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Solution Overview

Problem

The high cost and limited availability of indium in oxide semiconductors used in thin film transistors (TFTs) for display devices, leading to increased production costs and sustainability issues, necessitate the development of alternative semiconductor materials.

Innovation Solution

The use of lanthanum boride as a semiconductor active layer in TFTs, which reduces indium usage and leverages the greater abundance and lower consumption of lanthanum, enhancing electron mobility and conductivity, thereby improving the on/off current ratio and display performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oxide semiconductor containing indium is used as active layer, then high mobility and high on-state current are achieved, but production cost increases and mass production is limited

Engineering Contradiction:
ImprovemobilityVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material composition parameter by replacing indium-based oxide semiconductor with lanthanum boride, maintaining the semiconductor properties while eliminating dependence on scarce and expensive indium resources

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes expensive indium with abundant and cheaper lanthanum boride material, making mass production economically viable while maintaining device performance

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If oxide semiconductor containing indium is used as active layer, then high mobility and high on-state current are achieved, but indium availability decreases and sustainability is compromised

Engineering Contradiction:
ImprovemobilityVSAvoidindium consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent fundamentally changes the material composition from indium-based to lanthanum-based semiconductor, eliminating the consumption of scarce indium while maintaining high mobility through the unique electronic structure of lanthanum boride

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces scarce indium with abundant lanthanum boride material, ensuring sustainable mass production by eliminating dependence on limited indium resources

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 implementation of lanthanum boride in TFTs decreases production costs, increases the on/off current ratio, prevents current leakage, and enhances charging rates, resulting in improved display effects and sustainable usage.

Implementation Method 1

The lanthanum boride pattern is semiconducting. The lanthanum boride pattern has a concentration of carries of 10^15 to 10^18 atoms/cm³

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3297031B1Thin-film transistor, array substrate and preparation methods therefor, and display device
Publication Date: 2020.01.08 BOE TECHNOLOGY GROUP CO LTD
  • EP3297031B1 patent drawingFigure 1~2b
  • EP3297031B1 patent drawingFigure 2c~3
  • EP3297031B1 patent drawingFigure 4~5

AI summary

The present disclosure provides a TFT, an array substrate, their manufacturing method, and a display device. The method for manufacturing the TFT includes a step of forming a pattern of a semiconductor active layer on a transparent substrate through a patterning process, and the pattern of the semiconductor active layer includes a lanthanum boride pattern.