Solar Cell Doped-Layer Patterning to Limit Laser Surface Damage

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Solution Overview

Problem

The laser irradiation process used to pattern localized emitters in tunnel oxide passivated contact (TOPCON) solar cells causes physical damage to the surface of the base, affecting the performance of the solar cell.

Innovation Solution

A method involving the concurrent formation of doped layers on the substrate, followed by localized laser irradiation and selective etching to pattern the doped layers, which reduces the need for additional masking and minimizes damage to the substrate by using the existing doped layers as protective layers during the patterning process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If laser irradiation process is used to pattern initial emitter, then localized emitter can be formed, but physical damage is caused to the surface of the base

Engineering Contradiction:
Improveemitter patterning precisionVSAvoidsurface damage
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

A doped semiconductor layer is formed on the substrate surface before the laser irradiation process. This pre-formed layer serves as a protective mask that absorbs or deflects the laser energy, preventing direct damage to the substrate surface while still allowing the laser to pattern the emitter through the doped layer.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The doped semiconductor layer acts as an intermediary between the laser irradiation process and the substrate surface. It mediates the interaction by providing a controlled interface that allows emitter patterning to occur while protecting the underlying substrate from harmful laser-induced damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If conventional emitter patterning method is used, then localized emitter is formed, but additional masking processes are required

Engineering Contradiction:
Improveemitter patterning precisionVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The doped semiconductor layer serves dual purposes: it functions as both the emitter material and the protective mask during the laser patterning process. This self-service approach eliminates the need for separate masking layers and their associated deposition and removal processes, thereby reducing overall process complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The protective mask function and the emitter material function are merged into a single doped semiconductor layer. This consolidation eliminates the need for separate masking processes, reducing the number of process steps while maintaining the required patterning precision.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If doped layers are formed before laser patterning, then substrate protection is achieved, but additional process steps are added

Engineering Contradiction:
Improvesurface damageVSAvoidmanufacturing efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The doped semiconductor layer performs multiple functions simultaneously: it serves as the emitter material, provides protection during laser patterning, and acts as a self-aligned mask. This multi-functionality means that while an additional formation step is required, it replaces multiple separate processes (mask deposition, masking, and potential removal), thereby maintaining or even improving overall manufacturing efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 method effectively mitigates damage to the solar cell surface during emitter patterning, reducing process operations and costs while maintaining the integrity of the substrate, thereby enhancing the performance of the solar cell.

Implementation Method 1

patterning the second doped layer includes localized laser irradiation

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

etching away the portions of the target doped dielectric layer over the respective first regions

Methodology Applied
Scientific EffectEtching:

Data Source

PatentEP4629781A1Method for manufacturing a solar cell
Publication Date: 2025.10.08 ZHEJIANG JINKO SOLAR CO LTD
  • EP4629781A1 patent drawingFigure 1~2
  • EP4629781A1 patent drawingFigure 3~4
  • EP4629781A1 patent drawingFigure 5~6

AI summary

Provided is a method for manufacturing a solar cell, including: providing a substrate having a first surface and a second surface opposite to each other forming a first doped layer on the second surface and concurrently forming a second doped layer on a target doped dielectric layer; performing a patterning process to remove a portion of the second doped layer over the first region; etching away the portion of the target doped dielectric layer over the first region; etching away a portion of the target doped semiconductor layer over the first region, and etching away a portion of the second doped layer over the second region; and etching away the portion of the target doped dielectric layer over the second region, a portion of the target doped semiconductor layer over the second region being reserved as a doped semiconductor portion. The respective first regions and the respective second regions are alternatingly distributed.