Solar Cell Tunnel Layer Layout for Lower Resistance and Recombination
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Solution Overview
Problem
The reduction in thickness of doped polysilicon in solar cells to minimize light absorption leads to increased lateral transport resistance and carrier recombination, thereby reducing photoelectric conversion efficiency.
Innovation Solution
A solar cell design with a first doped conductive layer having varying thickness and doping concentration in different regions, combined with tunneling layers and passivation layers, to optimize carrier transport and reduce recombination, improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the thickness of the doped polysilicon layer is reduced to minimize light absorption, then the photoelectric conversion efficiency is improved, but the lateral transport resistance increases and carrier recombination probability increases
Solution Approach 1:
The patent applies local quality by creating different thickness profiles of the doped polysilicon layer in different regions of the solar cell. Specifically, the tunneling layer has a first thickness in the first region and a second thickness in the second region, allowing optimization of light absorption in some areas while maintaining carrier transport in others. This spatial variation in layer thickness resolves the contradiction between minimizing light absorption loss and ensuring reliable carrier transport.
Solution Approach 2:
The patent employs parameter changes by varying the thickness parameter of the doped polysilicon layer across different regions. By adjusting the thickness parameter locally rather than uniformly, the patent achieves both reduced light absorption (through thinner regions) and maintained carrier transport (through thicker regions with appropriate doping), thus resolving the technical contradiction.
2Productivity
If the thickness of the doped polysilicon layer is reduced to enhance photoelectric conversion efficiency, then light absorption is minimized, but the transverse resistance increases
Solution Approach 1:
The patent segments the doped polysilicon layer into multiple regions with different thickness characteristics. The tunneling layer is divided into a first region with a first thickness and a second region with a second thickness. This segmentation allows the structure to simultaneously achieve low light absorption (through thinner segments) and low transverse resistance (through thicker segments with proper doping), resolving the contradiction between productivity and manufacturing precision.
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
The design reduces transverse resistance and recombination, enhancing the photoelectric conversion efficiency of the solar cell by optimizing the structure and doping of the doped conductive layers and tunneling layers.
Implementation Method 1
a first tunneling layer, a first doped conductive layer, and a second doped conductive layer. The first tunneling layer is arranged on a side of the substrate, and the first tunneling layer has a greater thickness in the first region than in the second region
Implementation Method 2
The dopant element in the second doped conductive layer is from the first doped conductive layer
Implementation Method 3
A solar cell can directly convert solar radiation energy into electrical energy, based on a photovoltaic effect of crystalline silicon
Data Source
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AI summary
Provided are a solar cell and a photovoltaic module. The solar cell includes a body and a first electrode. The body has a first region and a second region, and at least part of the first region covers the first electrode. The body includes a substrate, a first tunneling layer, a first doped conductive layer, and a second doped conductive layer. The first tunneling layer has a greater thickness in the first region than in the second region. The first tunneling layer is arranged between the first doped conductive layer and the second doped conductive layer. The first electrode is electrically connected to the first doped conductive layer. The second doped conductive layer is located on a side of the substrate close to the first tunneling layer. The second doped conductive layer has a less thickness in the first region than in the second region.