Dilute Source Vertical Organic Light Emitting Transistor for High Drive Currents

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Solution Overview

Problem

Existing display technologies face challenges in achieving high drive currents for organic light-emitting diodes (OLEDs) while maintaining low power consumption and high manufacturing efficiency, as polycrystalline silicon-based thin film transistors are costly and non-uniform, and organic semiconductor materials fail to match the output currents of poly-Si TFTs.

Innovation Solution

The development of a dilute source-enabled vertical organic light emitting transistor (DS-VOLET) that integrates the driving transistor and storage capacitor within its structure, utilizing a dilute carbon nanotube network as the source electrode to achieve high drive currents without the need for high-resolution patterning, thereby reducing manufacturing costs and increasing the light emitting area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If polycrystalline silicon-based thin film transistors are used to achieve high drive currents, then the output current is improved, but the manufacturing cost increases and uniformity deteriorates

Engineering Contradiction:
Improvedrive currentVSAvoidmanufacturing cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter from polycrystalline silicon to organic semiconductor materials, enabling the transistor to achieve high drive currents while being compatible with low-cost manufacturing processes and maintaining uniformity through solution-based fabrication methods

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures including organic semiconductor layers combined with specific electrode materials and encapsulation layers, creating a hybrid system that delivers both high performance and manufacturing efficiency

Inventive Principle:
Principle #40Composite materials

2Area of stationary object

If conventional lateral TFT structure is used, then the device structure is simple, but the light emitting area is reduced and aperture ratio deteriorates

Engineering Contradiction:
Improvelight emitting areaVSAvoiddevice structure
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent transitions from a conventional lateral (planar) TFT structure to a vertical TFT architecture, stacking the source, drain, and active layer vertically to enable the light emitting diode to occupy the horizontal plane, thereby maximizing the light emitting area and aperture ratio

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent merges the driving transistor and storage capacitor into a single integrated vertical structure, where the transistor's gate structure simultaneously serves as the capacitor electrode, reducing device complexity while maximizing the light emitting area

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If high-resolution patterning is used to achieve precise device fabrication, then the manufacturing precision is improved, but the manufacturing cost and complexity increase

Engineering Contradiction:
Improvedevice fabrication precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the fabrication approach from requiring high-resolution photolithographic patterning to using solution-based deposition methods with self-organizing materials, achieving precise device structures through material properties rather than complex patterning processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs materials and processes that self-organize during fabrication, such as solution-cast organic semiconductor layers that automatically form uniform films and defined structures, eliminating the need for high-resolution external patterning tools

Inventive Principle:
Principle #25Self-service

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 DS-VOLET design allows for high drive currents comparable to poly-Si TFTs while reducing power consumption and manufacturing costs, with improved aperture ratio and switching speed, enabling efficient operation of OLEDs with increased light emitting area and extended device lifetime.

Implementation Method 1

vertical organic light emitting transistor (DS-VOLET) that integrates the driving transistor and storage capacitor within its structure, utilizing a dilute carbon nanotube network as the source electrode to achieve high drive currents

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2649659B1Active matrix display comprising a dilute source enabled vertical organic light emitting transistor
Publication Date: 2020.05.06 UNIV OF FLORIDA RESEARCH FOUNDATION INC
  • EP2649659B1 patent drawingFigure 1A
  • EP2649659B1 patent drawingFigure 1B
  • EP2649659B1 patent drawingFigure 1C

AI summary

Various embodiments are provided for dilute source enabled vertical organic light emitting transistors. In various embodiments, a display panel includes an array of pixels. In one embodiment, among others, at least one pixel includes a switching transistor and a driving transistor coupled to the switching transistor, where the driving transistor is configured to emit light responsive to activation by the switching transistor. The driving transistor may be a dilute source enabled vertical organic light emitting transistor (DS- VOLET). The switching transistor may include a dilute source enabled vertical-field effect transistor (DS-VFET). In another embodiment, a double dilute source enabled vertical-field effect transistor (DS-VFET) includes a first DS-VFET coupled to a second DS-VFET.