Sacrificial Layer for Multi-Junction Solar Cell Substrate Separation
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Solution Overview
Problem
Existing methods for producing multi-junction solar cells are inefficient in separating the cells from substrates without damaging either the substrate or the solar cell, leading to high production costs and limited scalability for high-efficiency solar cells.
Innovation Solution
A method involving a sacrificial layer with a band gap energy of less than 1.5 eV, which is thermally decomposed using electromagnetic radiation, allowing for the cost-effective and reliable separation of multi-junction solar cells from substrates, enabling reuse of substrates and the addition of more partial solar cells, thereby reducing production costs and increasing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical etching or ion implantation methods are used to separate solar cell layers from substrates, then separation can be achieved, but the substrate or solar cell may be damaged and production costs increase
Solution Approach 1:
A sacrificial layer is deposited on the substrate surface before growing the semiconductor layers. This preliminary action creates a predefined separation interface that enables clean detachment later without damaging the substrate or solar cell, resolving the contradiction between reliable separation and manufacturing ease
Solution Approach 2:
The sacrificial layer acts as an intermediary between the substrate and the solar cell structure. It provides a controlled separation interface that allows the solar cell to be detached from the substrate without direct contact between the two, preventing damage and enabling cost-effective reuse of substrates
2Productivity
If multi-junction solar cells are produced with multiple partial solar cells stacked, then conversion efficiency increases, but the complexity of separating and reusing substrates increases
Solution Approach 1:
The sacrificial layer is deposited before stacking multiple partial solar cells, establishing a separation interface that works for the entire multi-junction structure. This allows efficient production of high-conversion-efficiency cells without increasing substrate separation complexity
Solution Approach 2:
The separation process is segmented into distinct steps: growing layers on substrate with sacrificial layer, completing the multi-junction structure, then detaching the finished product. This segmentation allows complex multi-junction cells to be produced efficiently while maintaining simple, standardized substrate reuse procedures
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 allows for the efficient separation of multi-junction solar cells from substrates without damage, reduces production costs, and enables the production of high-efficiency solar cells with improved throughput and yield, suitable for both space flight and terrestrial applications.
Implementation Method 1
a sacrificial layer with a band gap energy of less than 1.5 eV, which is thermally decomposed using electromagnetic radiation
Implementation Method 2
thermally decomposed using electromagnetic radiation, allowing for the cost-effective and reliable separation of multi-junction solar cells from substrates
Implementation Method 3
the first semiconductor body and the second semiconductor body form a material-to-material connection with a tunnel diode, and the first band gap is different from the second band gap
Data Source
AI summary
A semifinished product of a multi-junction solar cell includes a first semiconductor body that is designed as a first partial solar cell and has a first band gap, a second semiconductor body that is designed as a second partial solar cell and has a second band gap. The first semiconductor body and the second semiconductor body form a bonded connection to a tunnel diode and the first band gap is different from the second band gap. A first substrate material is adapted as a substrate layer, wherein a sacrificial layer is formed between the first substrate material and the first partial solar cell and the first substrate material is removed from the first semiconductor body, the sacrificial layer being destroyed in the process.