Graphene Switching Device Tunable Barrier
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Solution Overview
Problem
Graphene switching devices face challenges in achieving high on-current characteristics, making them unsuitable for analog circuits and RF applications due to low output conductance and limited maximum oscillation frequency.
Innovation Solution
A graphene switching device with a tunable semiconductor barrier is designed, featuring a semiconductor substrate with a doped well, a graphene layer, and a gate electrode, where the energy barrier can be adjusted by varying the gate voltage, and metal particles or an organic layer are used to enhance the on-current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a graphene switching device is used as a diode, then saturation may not occur during forward bias application, but it is difficult to apply to analog circuits due to low output conductance
Solution Approach 1:
The patent introduces a tunable energy barrier height that can be dynamically adjusted by applying different voltages to the gate electrode. This dynamic control allows the device to adapt its electrical characteristics, enabling it to function effectively in both analog circuits and RF applications by optimizing output conductance and transconductance parameters as needed
Solution Approach 2:
The patent changes the energy barrier height parameter through gate voltage control, which directly affects the carrier tunneling probability and current characteristics. By adjusting this parameter, the device achieves improved output conductance for analog circuit applications while maintaining the ability to operate in different bias conditions
2Reliability
If output conductance is good during reverse bias application, then transconductance may be reduced, but a cut-off frequency may be low making it difficult to apply to RF circuits
Solution Approach 1:
The tunable energy barrier allows dynamic optimization of device performance for different frequency ranges. By adjusting the gate voltage to create an appropriate energy barrier height, the device achieves high transconductance for low noise amplifier applications while maintaining a high cut-off frequency through controlled carrier tunneling
Solution Approach 2:
The patent modifies the energy barrier height parameter to control carrier transport, which simultaneously optimizes transconductance and cut-off frequency. The adjusted barrier enables efficient carrier injection for high transconductance while the narrow barrier width maintains high frequency response for RF circuit applications
3Reliability
If on-current is small, then transconductance may be reduced, but a cut-off frequency may be low
Solution Approach 1:
The patent changes the energy barrier height parameter through gate control, which exponentially affects carrier tunneling probability. By optimizing this parameter, the device achieves high on-current through enhanced tunneling while maintaining a narrow barrier width that supports high cut-off frequency operation
Solution Approach 2:
The dynamically tunable energy barrier enables the device to optimize both on-current and cut-off frequency simultaneously. The gate voltage control allows real-time adjustment of the barrier characteristics to achieve high current flow through improved tunneling while preserving the high frequency response needed for RF applications
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 tunable barrier configuration improves the on-current of graphene switching devices, enabling their application in RF circuits by optimizing the energy barrier and carrier tunneling, thus enhancing their performance.
Implementation Method 1
The first well is configured to form an energy barrier between the graphene layer and the first electrode
Implementation Method 2
a semiconductor substrate including a first well doped with an impurity
Implementation Method 3
the energy barrier may be configured to vary based on a voltage applied to the gate electrode
Implementation Method 4
a gate insulation layer on the graphene layer; and a gate electrode on the gate insulation layer
Data Source
AI summary
According to example embodiments, a graphene switching devices having a tunable barrier includes a semiconductor substrate that includes a first well doped with an impurity, a first electrode on a first area of the semiconductor substrate, an insulation layer on a second area of the semiconductor substrate, a graphene layer on the insulation layer and extending onto the semiconductor substrate toward the first electrode, a second electrode on the graphene layer and insulation layer, a gate insulation layer on the graphene layer, and a gate electrode on the gate insulation layer. The first area and the second area of the semiconductor substrate may be spaced apart from each other. The graphene layer is spaced apart from the first electrode. A lower portion of the graphene layer may contact the first well. The first well is configured to form an energy barrier between the graphene layer and the first electrode.