TOPCon Solar Cell Texturing to Reduce Lateral Surface Leakage
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Solution Overview
Problem
The manufacturing of tunnel oxide passivated contact (TOPCon) cells is hindered by leakage on lateral surfaces due to doping processes, which reduces solar cell efficiency.
Innovation Solution
The formation of pyramid base shaped textured structures on the lateral surfaces with specific side length and height differences relative to the second surface, combined with a polysilicon doped conductive layer and passivated contact layer, minimizes lateral surface leakage by controlled etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If doping processes are applied on front and back surfaces of TOPCon cells, then conductivity is improved, but leakage on lateral surfaces increases
Solution Approach 1:
The patent applies different textured structure configurations to different surfaces: the front surface maintains standard pyramid structures for optimal light absorption, while the back surface implements pyramid base structures with enlarged tops and reduced height. This local differentiation allows the back surface to minimize lateral doping diffusion while the front surface optimizes for光吸收，resolving the contradiction between conductivity and lateral leakage.
Solution Approach 2:
The patent performs preliminary texturing of the back surface to create pyramid base structures before the doping process. By pre-forming these structures with controlled top dimensions (smaller area than the base), the patent creates a physical barrier that limits lateral diffusion of dopants during subsequent doping steps, thereby preventing leakage channel formation before it occurs.
2Object-generated harmful factors
If pyramid base shaped textured structures are formed on lateral surfaces with larger top dimensions, then lateral surface leakage is reduced, but light absorption may be affected
Solution Approach 1:
The patent segments the cell into functionally distinct surfaces: the front surface (first surface) maintains traditional pyramid structures optimized for light absorption, while the back surface (second surface) implements pyramid base structures optimized for minimizing lateral leakage. This segmentation allows each surface to be optimized for its primary function without compromising the other, resolving the contradiction between leakage prevention and light absorption.
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 enhances solar cell efficiency by preventing leakage channels on lateral surfaces, improving the overall performance and reducing reverse current.
Implementation Method 1
a plurality of pyramid base shaped textured structures being constructed on the second surface and each of the lateral surfaces, wherein a minimum side length of each of top surfaces of the pyramid base shaped textured structures arranged on the lateral surfaces is L1, a maximum side length of each of top surfaces of the pyramid base shaped textured structures arranged on the second surface is L2, and L1>L2
Data Source
AI summary
A solar cell includes: a substrate including a first surface and a second surface arranged opposite to each other and a plurality of lateral surfaces adjacent to and located between the first surface and the second surface; a plurality of pyramid base shaped textured structures being constructed on the second surface and each of the lateral surfaces, wherein a minimum side length of each of top surfaces of the pyramid base shaped textured structures arranged on the lateral surfaces is L1, a maximum side length of each of top surfaces of the pyramid base shaped textured structures arranged on the second surface is L2, and L1>L2; a doped conductive layer arranged on the first surface; and a passivated contact layer including a polysilicon doped conductive layer, the passivated contact layer being arranged on the second surface.