Solar Cell Back-Surface Texturing for Passivation and Contact

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Solution Overview

Problem

Existing textured surface structures on solar cells can adversely affect subsequent film passivation and slurry contact interfaces, leading to performance issues in photovoltaic cells.

Innovation Solution

A semiconductor substrate with N-type and P-type conductive regions featuring non-pyramidal texture structures of specific sizes and shapes, designed to facilitate better film passivation and slurry contact, enhancing the solar cell's performance by optimizing the one-dimensional size and arrangement of these textures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a textured surface structure is adopted to increase light transport paths, then light utilization is improved, but film passivation and slurry contact interfaces are adversely affected

Engineering Contradiction:
Improvelight utilizationVSAvoidfilm passivation quality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The back surface is segmented into multiple conductive regions (N-type and P-type) with different texture structures, allowing each region to be optimized independently for its specific function while maintaining overall system performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different texture structures are applied to different conductive regions based on their specific requirements: smaller textures (5-12μm) for N-type regions requiring good passivation, and larger textures (10-40μm) for P-type regions requiring good slurry contact

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If a textured surface structure is adopted to increase light transport paths, then light utilization is improved, but slurry contact interface is adversely affected

Engineering Contradiction:
Improvelight utilizationVSAvoidslurry contact quality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The back surface is segmented into multiple conductive regions (N-type and P-type) with different texture structures, allowing each region to be optimized independently for its specific function while maintaining overall system performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different texture structures are applied to different conductive regions based on their specific requirements: smaller textures (5-12μm) for N-type regions requiring good passivation, and larger textures (10-40μm) for P-type regions requiring good slurry contact

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If uniform texture structures are used on all conductive regions, then manufacturing is simplified, but performance is compromised due to different regional requirements

Engineering Contradiction:
Improvetexture structure fabricationVSAvoidoverall cell performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The back surface is segmented into multiple conductive regions (N-type and P-type) with different texture structures, allowing each region to be optimized independently for its specific function while maintaining overall system performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different texture structures are applied to different conductive regions based on their specific requirements: smaller textures (5-12μm) for N-type regions requiring good passivation, and larger textures (10-40μm) for P-type regions requiring good slurry contact

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4297102A1Semiconductor substrate, solar cell, and photovoltaic module
Publication Date: 2023.12.27 ZHEJIANG JINKO SOLAR CO LTD
  • EP4297102A1 patent drawingFigure 1
  • EP4297102A1 patent drawingFigure 2
  • EP4297102A1 patent drawingFigure 3~4

AI summary

A semiconductor substrate, including a back surface having N-type conductive regions and P-type conductive regions. The N-type conductive regions are provided with first non-pyramidal texture structures, and the P-type conductive regions are provided with second non-pyramidal texture structures. A top surface of the first non-pyramidal texture structure is a polygonal plane, and a top surface of the second non-pyramidal texture structure is a polygonal plane. A one-dimensional size of the top surface of the first non-pyramidal texture structure is less than a one-dimensional size of the top surface of the second non-pyramidal texture structure. The one-dimensional size of the top surface of the first non-pyramidal texture structure is in a range of 5 µm to 12 µm. The one-dimensional size of the top surface of the second non-pyramidal texture structure is in a range of 10 µm to 40 µm.