Monolithic Stacked Voltage Source for High-Voltage Photon Conversion

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Solution Overview

Problem

Existing scalable voltage sources, particularly those using III-V materials, face limitations in achieving high voltage outputs efficiently and cost-effectively, with prior art struggling to produce voltages above 2.2V and requiring larger illumination areas.

Innovation Solution

A scalable voltage source is designed with multiple semiconductor diodes connected in series, featuring p-n junctions with specific band gap properties and tunnel diodes, monolithically integrated to form a stack with a total thickness less than 12 µm, allowing for efficient photon current utilization and achieving source voltages greater than 2.2V.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple semiconductor diodes are connected in series to achieve high voltage output, then the source voltage increases, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvesource voltageVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

Multiple semiconductor diodes are merged into a single monolithic stack structure where they are grown together on a common substrate using epitaxial techniques. This integration reduces the number of separate components and interconnections needed, simplifying the overall device while maintaining the high voltage output achieved through series connection of individual diode junctions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from planar lateral arrangements of diodes to a vertical stacked configuration. By stacking diodes in the vertical dimension with tunnel diodes positioned between them, the design achieves high voltage output in a compact footprint, reducing the illumination area required while maintaining series connection functionality.

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

2Ease of manufacture

If the illumination area is reduced to improve cost-effectiveness, then the manufacturing cost decreases, but the light utilization efficiency may be compromised

Engineering Contradiction:
Improvecost-effectivenessVSAvoidlight utilization efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent implements localized optical optimization by positioning tunnel diodes with specific band gap properties at strategic locations between the semiconductor diodes in the stack. This local quality enhancement allows for more efficient photon utilization at specific interfaces, maximizing light conversion efficiency within the reduced illumination area.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the total thickness is reduced to less than 12 µm to improve integration density, then the device miniaturization increases, but the mechanical stability and photon absorption efficiency may be compromised

Engineering Contradiction:
Improvetotal thicknessVSAvoidmechanical stability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent employs a composite stack structure alternating between semiconductor diodes with specific band gaps and tunnel diodes with higher band gaps. This composite arrangement creates a mechanically robust structure where different material layers support each other, maintaining structural integrity while achieving thin-film integration. The alternating layers also optimize both mechanical stability and optical absorption efficiency.

Inventive Principle:
Principle #40Composite materials

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 enables the production of voltage values above 3V with a smaller illumination area, improving scalability and cost-effectiveness while maintaining mechanical stability and efficient light utilization.

Implementation Method 1

a tunnel diode is formed between each two consecutive partial voltage sources

Methodology Applied
Scientific EffectQuantum tunneling:

Implementation Method 2

each of the partial voltage sources has a semiconductor diode with a pn junction, and the semiconductor diode has a p-doped absorption layer

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3144982B1Scalable voltage source
Publication Date: 2024.05.15 AZUR SPACE SOLAR POWER
  • EP3144982B1 patent drawingFigure 1~2
  • EP3144982B1 patent drawingFigure 3~4
  • EP3144982B1 patent drawingFigure 5~6

AI summary

A scalable voltage source comprising a number N of partial voltage sources connected in series as semiconductor diodes, wherein each of the partial voltage sources is a semiconductor diode with a pn junction, and each semiconductor diode has a p-doped absorption layer, wherein the p-absorption layer is passivated by a p-doped passivation layer with a band gap larger than the band gap of the p-absorption layer, and the semiconductor diode has an n-absorption layer, wherein the n-absorption layer is passivated by an n-doped passivation layer with a band gap larger than the band gap of the n-absorption layer, and the partial voltages of the individual partial voltage sources have a deviation of less than 20% from each other, and a tunnel diode is formed between each pair of successive partial voltage sources.wherein the tunnel diode has several semiconductor layers with a higher band gap than the band gap of the p/n absorption layers, and the semiconductor layers with the higher band gap each consist of a material with a modified stoichiometry and/or elemental composition than the p/n absorption layers of the semiconductor diode, and the partial voltage sources and the tunnel diodes are monolithically integrated together, and together form a first stack with a top and a bottom, and the number N of partial voltage sources is greater than or equal to two, and the light strikes the stack at the top, and the size of the illumination area at the top of the stack is essentially the size of the area of ​​the stack at the top, and the first stack has a total thickness of less than 12 µm, and at 300 K the first stack has a source voltage greater than 2.2 volts,provided that the first stack is irradiated with a photon stream of a specific wavelength, and wherein, in the direction of incidence of the light, the total thickness of the p and n absorption layers of a semiconductor diode increases from the top diode to the bottom diode.