Organic Semiconductor Transistor Contact Resistance Reduction
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Solution Overview
Problem
Conventional doping methods for organic semiconductor transistors, which reduce contact resistance, are limited to top-gate structures and often result in high contact resistance between organic semiconductor materials and metal electrodes, limiting device performance.
Innovation Solution
The introduction of a dopant layer formed by injecting dopant molecules downward from the upper portion of the channel layer, allowing for solid-state diffusion and reducing contact resistance between the organic semiconductor and metal electrodes, while maintaining structural freedom, using poly(2,5-bis (3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) as the organic semiconductor and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane as dopant molecules, and incorporating a self-assembled monolayer and plasma-etching the channel layer surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional doping method is used to reduce contact resistance, then contact resistance is reduced, but the method is limited to top-gate structures and cannot be applied to other transistor configurations
Solution Approach 1:
The patent inverts the conventional doping approach by forming the dopant layer at the bottom interface between the organic semiconductor and electrode, rather than doping the upper surface. This inversion allows the doping method to be applied to various transistor structures including bottom-gate and top-gate configurations, thereby improving versatility while maintaining contact resistance reduction benefits
2Reliability
If doping is performed on the upper surface of organic semiconductor thin film, then contact resistance is reduced, but the doping is limited to specific transistor structures
Solution Approach 1:
The patent transitions from surface-level doping (two-dimensional approach) to interface-level doping at the bottom contact region. By forming the dopant layer between the organic semiconductor and electrode in the vertical dimension, the method eliminates structural constraints and can be applied to various transistor configurations without increasing device complexity
3Reliability
If dopant molecules are injected downward from upper portion of channel layer, then contact resistance is reduced and charge injection is enhanced, but structural freedom must be maintained
Solution Approach 1:
The patent applies local quality by concentrating dopant molecules specifically at the bottom interface region where contact resistance occurs, rather than uniformly distributing them throughout the channel layer. This localized doping approach reduces contact resistance while maintaining structural freedom and compatibility with various transistor configurations
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
This approach effectively reduces contact resistance, enhances charge injection, and improves the ON/OFF ratio and mobility of the organic semiconductor transistor, particularly in low-power applications, allowing for flexible substrate use and structural freedom without degrading the organic semiconductor layer properties.
Implementation Method 1
the dopant molecules and the organic semiconductor form a material combination in which the dopant molecules diffuse in the organic semiconductor in a solid-state diffusion manner
Implementation Method 2
An upper surface of the channel layer is plasma-etched
Data Source
AI summary
An organic semiconductor transistor is provided. The organic semiconductor transistor includes a gate electrode, a gate insulating layer positioned on the gate electrode, a source electrode and a drain electrode which are positioned on the gate insulating layer and spaced apart from each other, a channel layer formed of an organic semiconductor on the gate insulating layer on which the source electrode and the drain electrode are formed, and a dopant layer formed by injecting dopant molecules downward from an upper portion of the channel layer, wherein the dopant layer is formed to be spaced above a position at which each of the source electrode and the drain electrode is in contact with the channel layer, and the dopant molecules and the organic semiconductor form a material combination in which the dopant molecules diffuse in the organic semiconductor in a solid-state diffusion manner.