Solar Cell Doping Openings Using Laser Patterning and Tunneling Layers

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Solution Overview

Problem

Current solar cell manufacturing methods face challenges in achieving high efficiency and productivity, particularly in the design of layers and electrodes, which affects their commercial viability.

Innovation Solution

A method for manufacturing a solar cell involving a semiconductor substrate with a tunneling layer, conductive areas, and electrodes, where laser marks are used to pattern the conductive areas, and a back surface passivation film is applied to enhance tunneling effects and prevent shunting, while a front surface passivation film and anti-reflection film are used to improve light absorption and reduce recombination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If wet etching technique or etching paste is used for forming doping opening, then manufacturing process can be simplified, but manufacturing precision and productivity are reduced

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoiddoping opening precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces wet etching (chemical process) with laser processing (optical/thermal process) for forming doping openings. The laser beam precisely ablates the semiconductor material to create openings with controlled dimensions, eliminating the precision limitations of wet etching while maintaining process simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the processing parameters by using laser power, pulse duration, and scanning speed as controllable parameters instead of chemical etchant concentration and exposure time. This allows precise control of opening size and shape through parameter optimization, achieving both high precision and manufacturing efficiency.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional layer design is used, then manufacturing process is straightforward, but photoelectric conversion efficiency is low

Engineering Contradiction:
Improvemanufacturing straightforwardnessVSAvoidphotoelectric conversion efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent implements local quality by creating specific doping patterns with varying concentrations and types in different regions of the semiconductor substrate. The back surface features localized n-type and p-type doping areas with optimized concentrations, while the front surface has selective doping regions, allowing each area to perform its specific function for maximizing photoelectric conversion.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite material structures by combining different semiconductor materials (e.g., silicon substrate with diamond-like carbon coating, or multi-layer semiconductor compounds). This composite approach enhances both manufacturing feasibility and photoelectric conversion efficiency through material property optimization.

Inventive Principle:
Principle #40Composite materials

3Reliability

If more layers and electrodes are added to improve efficiency, then photoelectric conversion efficiency increases, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvephotoelectric conversion efficiencyVSAvoidlayer and electrode structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into fewer layers and structures. For example, the back surface contact structure integrates doping regions, electrode contacts, and passivation functions into a unified design. The laser processing method also combines opening formation, doping, and patterning steps into a single processing approach, reducing overall device complexity while maintaining high efficiency.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If conventional etching methods are used, then manufacturing process is simple, but productivity is reduced due to low precision requirements

Engineering Contradiction:
Improveetching process simplicityVSAvoidmanufacturing productivity
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces conventional batch wet etching processes with laser-based processing, which can be performed continuously or in rapid sequence. The laser method eliminates the need for chemical baths, masking, and multiple rinsing steps, significantly reducing cycle time and increasing productivity while maintaining process simplicity through direct material removal.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 results in improved photoelectric conversion efficiency, reduced light loss, and simplified manufacturing processes, leading to higher productivity and efficiency of the solar cells.

Implementation Method 1

patterning said conductive areas with a laser, thereby forming laser marks

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

a front surface passivation film and anti-reflection film are used to improve light absorption

Methodology Applied
Scientific EffectAnti-reflection: Anti-Reflective Coating

Data Source

PatentEP3098860B1Method of manufacturing a solar cell
Publication Date: 2024.07.31 SHANGRAO JINKO SOLAR TECH DEV CO LTD
  • EP3098860B1 patent drawingFigure 1
  • EP3098860B1 patent drawingFigure 2
  • EP3098860B1 patent drawingFigure 3(a)~4A

AI summary

Disclosed is a method of manufacturing a solar cell, the method including forming a tunneling layer over one surface of a semiconductor substrate, forming a semiconductor layer over the tunneling layer, forming a conductive area including a first conductive area of a first conductive type and a second conductive area of a second conductive type in the semiconductor layer, and forming an electrode including a first electrode connected to the first conductive area and a second electrode connected to the second conductive area. The forming of the conductive area includes forming a mask layer over the semiconductor layer, forming a doping opening corresponding to at least one of the first conductive area and the second conductive area in the mask layer using a laser, and performing doping using the doping opening.