Solar Cell Differential Thickness Electrodes Light Area
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Solution Overview
Problem
The light receiving area of solar cells is reduced due to the presence of first electrodes and bus bars on the emitter layer, which decreases their efficiency.
Innovation Solution
The solar cell design includes first electrodes and a first current collector on the emitter layer, where the thickness of the electrodes is different from the current collector, with the electrode thickness being equal to or less than half the current collector thickness, and a crossing configuration to minimize area coverage and maximize light reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If first electrodes and bus bars are positioned on the emitter layer to collect current, then electrical connection is achieved, but the light receiving area decreases
Solution Approach 1:
The patent applies local quality by making the thickness of first electrodes different from the thickness of the current collector. Specifically, the first electrodes have a thickness of 0.03-0.08 μm while the current collector has a thickness of 0.06-0.15 μm. This differential thickness optimization allows the electrodes to provide sufficient electrical connection while minimizing their area coverage on the light receiving surface, thereby resolving the contradiction between electrical connection reliability and light receiving area.
2Reliability
If thicker electrodes are used to improve electrical connection, then contact resistance decreases, but the area occupied by electrodes increases reducing light reception
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness parameter of the first electrodes to be 0.03-0.08 μm, which is specifically controlled to be less than the thickness of the current collector (0.06-0.15 μm). This parameter optimization ensures that the electrodes provide adequate electrical connection with acceptable contact resistance while occupying minimal area on the light receiving surface, thus resolving the contradiction between contact resistance and electrode area.
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 design increases the light receiving area of the solar cell, thereby enhancing its efficiency by reducing the area occupied by electrodes and preventing contact resistance and shunt generation.
Implementation Method 1
When light is incident on the solar cell, electrons inside the semiconductors become free electrons (hereinafter referred to as 'electrons') by the photoelectric effect.
Implementation Method 2
electrons and holes respectively move to the n-type semiconductor (e.g., the emitter layer) and the p-type semiconductor (e.g., the substrate) in accordance with the principle of the p-n junction
Data Source
AI summary
A solar cell and a solar cell module including the solar cells are disclosed. The solar cell includes a substrate of a first conductive type; an emitter layer of a second conductive type positioned at a light receiving surface of the substrate; a plurality of first electrodes that are positioned on the emitter layer and are electrically connected to the emitter layer; and at least one first current collector that is positioned on the emitter layer in a direction crossing the plurality of first electrodes, wherein a thickness of each of the plurality of first electrodes is different from a thickness of the at least one first current collector, and a difference of the thickness of the each first electrode to the thickness of the at least one current collector is equal to or less than about 0.5 times the thickness of the at least one first current collector.