Flip-Chip Solar Cell Structure for Low-Mass Space Power
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Solution Overview
Problem
Multi-junction solar cells face challenges due to expensive and complex manufacturing processes, as well as high substrate density, which complicates their use in weight-sensitive applications like satellites and solar-powered aerial vehicles.
Innovation Solution
The development of a flip-chip solar cell structure that bonds epitaxial layers to a sapphire coverglass layer, reducing substrate weight and complexity while maintaining structural integrity and enhancing radiation transmission, using a transparent bond between the semiconductor layers and the coverglass layer without interposed metal, and employing a thin sapphire layer for weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If multi-junction solar cells use traditional substrates, then high conversion efficiency is achieved, but substrate weight increases significantly
Solution Approach 1:
The patent extracts and removes the traditional heavy substrate from the solar cell structure, retaining only the essential semiconductor layers needed for photovoltaic conversion. This extraction eliminates unnecessary weight while preserving the core functionality of converting solar radiation to electrical energy.
Solution Approach 2:
The patent employs thin film structures for the semiconductor layers, replacing bulky traditional substrates. These thin films maintain the necessary optical and electrical properties for high-efficiency energy conversion while dramatically reducing the overall weight of the solar cell assembly.
2Loss of energy
If multi-junction solar cells use expensive substrates, then high conversion efficiency is achieved, but manufacturing cost increases
Solution Approach 1:
The patent extracts the expensive substrate component from the system, demonstrating that high-efficiency solar conversion can be achieved without relying on costly traditional substrates. This extraction opens pathways for using more economical materials and manufacturing approaches.
Solution Approach 2:
The patent adopts a strategy of using thinner, potentially less expensive semiconductor layers that can be manufactured more economically. While individual layers may be thinner and potentially less durable, the overall structure achieves the necessary performance at reduced cost, making the system more economically viable.
3Loss of energy
If multi-junction solar cells use complex manufacturing processes, then high conversion efficiency is achieved, but device complexity increases
Solution Approach 1:
The patent segments the solar cell into distinct functional layers (semiconductor layers, coverglass, bonding interface) that can be manufactured and characterized independently. This segmentation simplifies the overall manufacturing process by allowing each component to be optimized and assembled separately, reducing the complexity of integrated production.
Solution Approach 2:
The use of thin film structures enables simpler manufacturing processes compared to traditional bulk substrate methods. Thin films can be deposited using more accessible techniques and require less complex processing steps, thereby reducing device complexity while maintaining high conversion efficiency.
4Weight of moving object
If coverglass layer is made thinner to reduce weight, then mass per area decreases, but structural strength may be compromised
Solution Approach 1:
The patent utilizes thin film technology for the coverglass layer, demonstrating that sufficiently thin structures can maintain adequate structural strength through optimized material selection and design. The thin coverglass reduces mass per area while retaining enough strength to protect the semiconductor layers and maintain structural integrity.
Solution Approach 2:
The patent employs composite material strategies where the coverglass is integrated with bonding layers and semiconductor structures to create a composite assembly. This composite structure distributes mechanical loads across multiple components, allowing the coverglass itself to be thinner while the overall assembly maintains necessary structural strength.
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 improves the strength and efficiency of solar cells, reduces manufacturing complexity, and achieves a lower mass per area, making them suitable for non-terrestrial applications by maximizing solar radiation transmission and structural compatibility.
Implementation Method 1
Solar power generation systems use the photovoltaic effect to convert solar radiation into electrical power.
Implementation Method 2
a coverglass layer coupled to the second side via a bond
Data Source
AI summary
Methods, devices, and systems are described for a flip-chip solar cell. The flip-chip solar cell includes a plurality of semiconductor layers having a first side and a second side. The plurality of semiconductor layers are configured to convert solar radiation to electrical energy. The flip-chip solar cell includes a coverglass layer coupled to the second side via a bond. The coverglass layer is configured to pass the solar radiation to the plurality of semiconductor layers and provide structural support for the plurality of semiconductor layers flip-chip solar cell. The flip-chip solar cell includes a first electrode pad and a second electrode pad coupled to the first side and electrically coupled to the plurality of semiconductor layers. The coverglass layer is thicker than the plurality of semiconductor layers. No metal layer is interposed between the plurality of semiconductor layers and the coverglass layer.