Band-Gap Engineered Semiconductor Diode for Charge Trapping
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Solution Overview
Problem
Current semiconductor diodes face challenges in increasing charge storage capacity, particularly due to inefficient trapping of carriers at trapping levels, leading to recombination of electrons and holes before they can be stored effectively.
Innovation Solution
The semiconductor diode design incorporates a P-type semiconductor with a wide band gap, an N-type semiconductor with a smaller band gap, and an insulator with a band gap larger than both, ensuring a 1 eV or higher difference between the P-type and N-type semiconductors and a 1 eV or lower difference between the insulator and P-type semiconductor, facilitating efficient trapping of holes at the insulator and interface levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a conventional semiconductor diode structure is used, then the device is simple and easy to manufacture, but the charge storage capacity is insufficient due to carrier recombination
Solution Approach 1:
The patent applies parameter changes by carefully selecting and controlling the band gap values of different semiconductor layers. Specifically, the P-type semiconductor has a band gap of 2.0-3.0 eV, the N-type semiconductor has a band gap of 0.5-1.5 eV, and the insulating layer has a band gap of 3.5-4.5 eV. This parameter optimization ensures that holes are trapped at the insulator-semiconductor interface while electrons remain in the conduction band, preventing recombination and enhancing charge storage capacity.
Solution Approach 2:
The patent employs composite materials by creating a multi-layer structure consisting of P-type semiconductor, N-type semiconductor, and insulating layer. Each layer is composed of specific materials with tailored band gap properties: the P-type semiconductor (e.g., TiOx), N-type semiconductor (e.g., NiOx), and insulating layer (e.g., SiN) work together to achieve efficient charge separation and storage, resolving the contradiction between simplicity and charge storage capacity.
2Quantity of substance
If the band gap difference between P-type and N-type semiconductors is small, then the device structure is easier to fabricate, but carrier recombination occurs before trapping, reducing charge storage efficiency
Solution Approach 1:
The patent resolves this contradiction by establishing specific parameter ranges for band gap control. The P-type semiconductor is designed with a band gap of 2.0-3.0 eV, the N-type semiconductor with 0.5-1.5 eV, creating a difference of 1.0-2.0 eV. The insulating layer has a band gap of 3.5-4.5 eV, with a difference of 0.5-1.5 eV from the P-type semiconductor. These precisely controlled parameters ensure efficient charge trapping while remaining achievable through standard semiconductor fabrication processes.
3Quantity of substance
If the insulator band gap is closer to the N-type semiconductor, then electron trapping is improved, but hole trapping efficiency decreases and recombination increases
Solution Approach 1:
The patent optimizes the insulator band gap parameter to be 3.5-4.5 eV, which is closer to the P-type semiconductor band gap (2.0-3.0 eV) than to the N-type semiconductor band gap (0.5-1.5 eV). This creates a energy barrier that effectively traps holes at the insulator-P-type semiconductor interface while preventing electron trapping, thereby eliminating recombination pathways and ensuring stable charge storage.
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 configuration allows for enhanced charge storage capacity by preventing recombination of holes and electrons, enabling efficient accumulation and release of electric charge, even under varying bias voltages, while maintaining a thin device form factor.
Implementation Method 1
the insulator having a band gap larger than the band gap of the P-type semiconductor and the band gap of the N-type semiconductor
Implementation Method 2
carriers are captured at the trapping level in the semiconductor diode when the current flows, and thereby, an electric charge is stored in the semiconductor diode
Data Source
AI summary
A semiconductor diode includes: a P-type semiconductor; an N-type semiconductor having a band gap smaller than a band gap of the P-type semiconductor; and an insulator provided between the P-type semiconductor and the N-type semiconductor, the insulator having a band gap larger than the band gap of the P-type semiconductor and the band gap of the N-type semiconductor, a difference between the band gap of the P-type semiconductor and the band gap of the N-type semiconductor is 1 eV or higher, and a difference between the band gap of the P-type semiconductor and the band gap the insulator is 1 eV or lower.