Nanowire Solar Cell on Polycrystalline Substrate
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Solution Overview
Problem
Conventional solar cell manufacturing relies on scarce and expensive high-quality single crystal silicon substrates, limiting the availability and increasing the cost of solar cells.
Innovation Solution
Growth of single crystalline nanowires on non-single crystalline materials such as polycrystalline silicon, amorphous silicon, or diamond-based substrates, which are inexpensive and can be used for solar cells, light emitters, and radiation detectors, reducing manufacturing costs and enabling efficient photon-to-electron conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high quality single crystal silicon substrates are used, then solar cell efficiency is improved, but manufacturing cost increases and material availability decreases
Solution Approach 1:
The patent segments the solar cell structure into distinct functional layers: a substrate layer (which can be inexpensive polycrystalline or amorphous silicon) and an active layer containing nanowire structures where photon-to-electron conversion occurs. This segmentation allows the expensive single crystal requirement to be localized only to the nanowire regions rather than the entire substrate.
Solution Approach 2:
The patent applies local quality by creating regions of high crystalline quality (single crystal nanowires) only where needed for efficient photon absorption and electron generation, while allowing the surrounding substrate to be lower quality (polycrystalline or amorphous). The nanowires are grown epitaxially on the substrate, creating localized high-quality regions that deliver the efficiency benefits without requiring the entire substrate to be expensive single crystal silicon.
2Reliability
If high quality single crystal silicon substrates are used, then solar cell efficiency is improved, but material scarcity increases
Solution Approach 1:
The patent replaces the expensive, scarce single crystal silicon substrate with inexpensive, readily available polycrystalline or amorphous silicon substrates. The critical single crystal structure is then grown only in the form of nanowires through epitaxial growth, using minimal amounts of high-quality material where it is most needed for photon absorption, rather than requiring large quantities of expensive single crystal substrate.
Solution Approach 2:
The patent creates a composite structure combining a low-cost substrate material (polycrystalline or amorphous silicon) with high-quality single crystal nanowire structures. This composite approach allows the system to benefit from the abundance and low cost of the substrate material while incorporating the high efficiency of single crystal silicon in the nanowire regions where it is most effective for photovoltaic conversion.
3Ease of manufacture
If non-single crystal substrates are used, then manufacturing cost decreases, but solar cell efficiency deteriorates
Solution Approach 1:
The patent introduces nanowire structures as an intermediary between the inexpensive substrate and the photon absorption function. The nanowires serve as a mediator that enables efficient photon-to-electron conversion on top of the low-cost substrate, bridging the gap between material cost and conversion efficiency. The nanowires are grown epitaxially from the substrate, creating a transition zone that maintains electrical continuity while providing the crystalline structure needed for efficient charge carrier generation.
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 production of efficient solar cells and light detectors using inexpensive materials, reducing manufacturing costs and overcoming the scarcity of high-quality silicon substrates, while maintaining the properties of single crystalline semiconductors.
Implementation Method 1
single crystalline nanowires can be grown on non-single crystalline material surfaces... enabling efficient photon-to-electron conversion
Data Source
AI summary
One embodiment in accordance with the invention is a solar cell comprising a non-single crystal substrate; a nanowire grown from a surface of the non-single crystal substrate; and an electrode coupled to the nanowire, wherein the nanowire is electrically conductive and is for absorbing electromagnetic wave and generating a current.