IBC Solar Cell Backside Doping Layout to Prevent Leakage
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Solution Overview
Problem
The photoelectric conversion efficiency of Interdigitated Back Contact (IBC) solar cells needs improvement due to structural limitations that can lead to electric leakage, process difficulties, and interference with carrier transport.
Innovation Solution
The solar cell design includes first and second doped parts with different dopant types, spaced apart, and a third doped part on one side of the first electrode, providing impurity absorption and acting as a protective layer to enhance efficiency and reduce process complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the PN junction and metal electrodes are located on the back surface of the solar cell in an IBC structure, then the short-circuit current and conversion efficiency are improved by eliminating front surface metal blocking, but the structural complexity increases and leads to electric leakage and process difficulties
Solution Approach 1:
The back surface of the solar cell is segmented into multiple functional regions: first doped parts for charge collection, second doped parts for passivation, and third doped parts as protective layers. This segmentation allows each region to perform its specific function independently, resolving the contradiction by organizing complexity into manageable, functionally-separated segments while maintaining the IBC architecture's efficiency benefits
Solution Approach 2:
Different doped parts are assigned different dopant types and functions at specific locations on the back surface. The first doped parts use one dopant type for charge collection, while the second and third doped parts use different dopant types for passivation and protection. This local differentiation of properties allows the structure to handle complexity through specialized local regions rather than uniform design
2Area of stationary object
If the first doped parts and second doped parts are placed close together on the back surface, then the space utilization is improved, but electric leakage occurs between adjacent doped parts
Solution Approach 1:
The third doped parts are introduced as intermediary protective layers positioned between the first doped parts and second doped parts. These intermediary structures act as barriers that prevent direct electrical interaction between adjacent doped parts, thereby eliminating leakage paths while allowing the doped parts to remain in close proximity for efficient space utilization
3Loss of energy
If additional doped parts and protective layers are added to the IBC structure, then the photoelectric conversion efficiency is improved, but the manufacturing process difficulty increases
Solution Approach 1:
The third doped parts are formed as protective layers in advance during the manufacturing process, before subsequent processing steps. This preliminary action of creating protective structures beforehand prevents damage to underlying doped parts during manufacturing, thereby improving efficiency without proportionally increasing process difficulty since the protective layers are integrated into the existing process flow
4Reliability
If the third doped part is placed close to the first electrode, then the protective coverage is improved, but the electrode transport function is interfered with
Solution Approach 1:
The third doped part is positioned to provide localized protection on one side of the first electrode rather than surrounding it completely. This localized placement provides protective coverage where most needed while leaving other sides open for carrier transport, resolving the contradiction through spatial differentiation of protection and transport functions
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 avoids electric leakage, improves photoelectric conversion efficiency, reduces process difficulty, and enhances the quality and yield of the solar cell by minimizing damage and impurity introduction during manufacturing.
Implementation Method 1
the third doped part can provide an impurity absorption effect for the first doped part, so as to improve the photoelectric conversion efficiency of the solar cell
Implementation Method 2
The third doped part can also be acted as a protective layer for the first doped part, in the process of preparing the solar cell, the third doped part can reduce the possibility of damage to the first doped layer or reduce the introduction of impurities to the first doped layer
Implementation Method 3
removing, by a laser processing, at least a portion of the initial first doped layer on the metal region to expose the metal region
Data Source
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AI summary
A solar cell, a method for manufacturing the same, and a photovoltaic module are provided. The solar cell includes a substrate, first and second doped parts, and first electrodes. The substrate has a first surface including first regions and second regions arranged alternatingly in a first direction. Each of the first and second doped parts is located on a corresponding first and second region, respectively and is separated from each other. Each first electrode and a third doped part are located on the corresponding first doped part. On the first doped part, the third doped part is located on at least one side of the first electrode in the first direction and is separated from the adjacent first electrode. The first doped parts are doped with dope elements different from the second doped parts and the third doped parts.