Back Contact Solar Cell Passivation Layout for P and N Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing back contact solar cells with surface passivation layers having both field and chemical passivation functions fail to satisfy the passivation requirements of both P and N regions, leading to poor working performance.
Innovation Solution
A back contact solar cell design with alternating doped semiconductor parts and dielectric passivation layers, where the conductivity types of the doped semiconductor parts are opposite, and the thickness and materials of the passivation sub-layers are tailored to enhance field and chemical passivation effects differently for each part, reducing the impact of one passivation layer on the other.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a surface passivation layer with both field passivation function and chemical passivation function is used, then the passivation effect on one region is improved, but the passivation requirement of the opposite conductivity type region cannot be satisfied
Solution Approach 1:
The passivation structure is segmented into two separate dielectric passivation layers: a first dielectric passivation layer for the first doped semiconductor part and a second dielectric passivation layer for the second doped semiconductor part. Each layer is independently optimized with different thicknesses and materials to satisfy the specific passivation requirements of each conductivity type region, resolving the contradiction between achieving strong passivation effect and satisfying both P and N region requirements simultaneously.
Solution Approach 2:
Different dielectric passivation layers are applied to different regions with different conductivity types. The first dielectric passivation layer has optimized thickness and material composition for the first doped semiconductor part, while the second dielectric passivation layer has different optimized parameters for the second doped semiconductor part. This local optimization allows each region to receive tailored passivation treatment, satisfying both passivation requirements simultaneously.
2Device complexity
If a single dielectric passivation layer is used for both doped semiconductor parts, then the device complexity is reduced, but the working performance of the solar cell deteriorates
Solution Approach 1:
The passivation system is divided into two separate dielectric passivation layers instead of using a single unified layer. This segmentation allows independent optimization of each layer's thickness and material properties to match the specific requirements of each doped semiconductor part, thereby improving working performance while managing device complexity through systematic design.
Solution Approach 2:
Different parameters (thickness, material composition) are assigned to different dielectric passivation layers based on the specific requirements of each doped semiconductor part. The first dielectric passivation layer has parameters optimized for the first doped semiconductor part, while the second dielectric passivation layer has parameters optimized for the second doped semiconductor part, achieving improved working performance through parameter differentiation.
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
Improves carrier collection and separation capabilities, reduces carrier recombination rates, and enhances the overall efficiency and performance of the back contact solar cell by satisfying the passivation requirements of both P and N regions.
Implementation Method 1
Each of the first dielectric passivation layer and the second dielectric passivation layer includes a first passivation sub-layer having a field passivation function
Implementation Method 2
Each of the first dielectric passivation layer and the second dielectric passivation layer further includes a second passivation sub-layer having a chemical passivation function
Implementation Method 3
sunlight irradiates onto a semiconductor p-n junction of the solar cell to form new hole-electron pairs
Data Source
AI summary
The present application discloses a back contact solar cell and a photovoltaic module. In one example, a back contact solar cell includes a semiconductor substrate, a first doped semiconductor part, a second doped semiconductor part, a first dielectric passivation layer, and a second dielectric passivation layer. Each of the first dielectric passivation layer and the second dielectric passivation layer includes a first passivation sub-layer having a field passivation function. A conductivity type of the first doped semiconductor part is opposite to that of fixed charges of the first passivation sub-layer. A thickness of the first passivation sub-layer included in the first dielectric passivation layer is greater than a thickness of the first passivation sub-layer included in the second dielectric passivation layer. Each of the first dielectric passivation layer and the second dielectric passivation layer further includes a second passivation sub-layer having a chemical passivation function.