Radionuclide Semiconductor Junction Structure for Radiation-Tolerant Power
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Solution Overview
Problem
Existing radioisotope-powered power cells face challenges in achieving an effective balance between durability and power output, particularly for radiation sources that emit x-rays and gamma rays, due to radiation-induced damage and low conversion efficiency.
Innovation Solution
An electrical generator system with a multi-layer structure comprising a radionuclide material, an n-type semiconductor layer, an intrinsic n-type material, a p-type material layer, and metal electrodes, where radiation emissions are converted into electrical energy at metal-semiconductor junctions, utilizing ZnO as an intrinsic n-type semiconductor and adding p-type material to enhance energy capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional semiconductors are used in radioisotope-powered power cells, then the device can generate electrical energy, but the semiconductor suffers collateral radiation damage from radioisotope decay products which reduces performance over time
Solution Approach 1:
The patent introduces an intermediary material (such as diamond, silicon carbide, or gallium nitride) between the radioisotope source and the semiconductor junction. This intermediary absorbs the harmful high-energy beta particles and other radiation before they reach the conventional semiconductor, thereby protecting it from radiation-induced defects while still allowing energy conversion to occur.
Solution Approach 2:
The patent changes the material parameters by selecting semiconductors with inherently higher radiation tolerance (such as wide-bandgap materials like GaN, SiC, or diamond) instead of conventional narrow-bandgap semiconductors. These materials have higher defect formation energies and can withstand radiation exposure without significant performance degradation, thus resolving the contradiction between power generation and durability.
2Power
If high energy radioisotopes are used to increase power output, then electrical power generation improves, but radiation damage to the semiconductor increases
Solution Approach 1:
The patent employs an intermediary protective layer that selectively filters the radiation spectrum. This intermediary allows lower-energy photons to pass through for energy conversion while absorbing or scattering the high-energy beta particles and gamma rays that cause damage, thus enabling the use of high-energy radioisotopes without proportionally increasing damage to the semiconductor.
3Power
If radiothermal generators use high energy radioisotopes like Pu-238, then electrical power can be produced, but substantial shielding is required and conversion efficiency is low
Solution Approach 1:
The patent replaces the thermal conversion mechanism of RTGs with a direct radiation-to-electricity conversion using semiconductor junctions. This substitution eliminates the need for thermal management systems and heavy shielding, as the semiconductor-based direct conversion operates efficiently with minimal protective requirements, thus resolving the contradiction between power production and device complexity.
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 system effectively generates electrical energy from x-ray and gamma ray emissions, maintaining stable operation over long periods despite constant irradiation, with improved durability and power output.
Implementation Method 1
radiation emissions received from said radionuclide material are converted into electrical energy at said metal-semiconductor junctions
Implementation Method 2
Another type of radioisotope-powered power cell is an indirect conversion device which uses a radioisotope, luminescent material and a photovoltaic cell. The decay particles emitted by the radioisotope excite the luminescent material. The light emitted by the luminescent material is absorbed by the photovoltaic cells to generate electricity.
Implementation Method 3
a layer of intrinsic n-type semiconductor material; wherein radiation emissions received from said radionuclide material are converted into electrical energy at said metal-semiconductor junctions
Data Source
AI summary
An electrical generator system including a radionuclide material; and a sandwich structure, the sandwich structure including: a layer of an n-type semiconductor material; a layer of intrinsic n-type semiconductor material; a layer of p-type semiconductor material; and metal electrodes, one of the electrodes being in direct contact with said n-type semiconductor material and another electrode being in contact with the p-type semiconductor material, forming metal-semiconductor junctions therebetween; wherein radiation emissions received from said radionuclide material are converted into electrical energy at said metal-semiconductor junctions; and electrical contacts connected to said electrodes which facilitate the flow of said electrical energy when connected to a load.