Solar Cell Dopant Layer Anti-Out-Diffusion Barrier

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Solution Overview

Problem

The existing methods for manufacturing solar cells face challenges in forming dopant layers with enhanced properties due to out-diffusion of dopants, which can lead to decreased dopant concentration and increased manufacturing costs when additional treatments are applied to prevent this issue.

Innovation Solution

A method involving ion-implantation of conductive type dopants followed by heat-treatment with anti-out-diffusion films formed at a controlled temperature and gas atmosphere to activate the dopants, preventing out-diffusion and enhancing dopant layer properties without additional processing steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If dopants are sufficiently doped to the semiconductor substrate during the process for forming the dopant layer, then the dopant layer has enhanced properties, but out-diffusion occurs causing decreased dopant concentration

Engineering Contradiction:
Improvedopant concentrationVSAvoiddopant loss
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

A silicon oxide film is formed on the semiconductor substrate before dopant implantation to act as a barrier layer preventing out-diffusion of dopants during heat treatment, while still allowing the dopants to be activated and incorporated into the substrate

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The silicon oxide film is formed in advance before dopant implantation and heat treatment, creating a protective barrier that prevents dopant loss during subsequent processing steps

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If additional treatment for preventing out-diffusion is performed, then dopant concentration is maintained, but manufacturing cost increases greatly

Engineering Contradiction:
Improvedopant concentrationVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The formation of the silicon oxide film is combined with the existing heat treatment process for dopant activation, eliminating the need for separate protective film formation steps and reducing manufacturing complexity

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If heat treatment is performed to activate dopants, then dopant layer properties are enhanced, but out-diffusion occurs reducing dopant concentration

Engineering Contradiction:
Improvedopant layer propertiesVSAvoiddopant loss
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The silicon oxide film serves as an intermediary barrier layer that allows thermal energy to pass through for dopant activation while blocking the diffusion path of dopant atoms to the surface

Inventive Principle:
Principle #24Intermediary (Mediator)

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 dopant layer properties, increased productivity, and enhanced solar cell efficiency by maintaining dopant concentration and reducing surface recombination velocity, leading to higher current density and open-circuit voltage.

Implementation Method 1

a method involving ion-implantation of conductive type dopants followed by heat-treatment with anti-out-diffusion films formed at a controlled temperature and gas atmosphere to activate the dopants

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Implementation Method 2

a method involving ion-implantation of conductive type dopants followed by heat-treatment

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Data Source

PatentEP2677546B1Method for manufacturing solar cell and dopant layer thereof
Publication Date: 2017.03.01 LG ELECTRONICS INC
  • EP2677546B1 patent drawingFigure 1
  • EP2677546B1 patent drawingFigure 2
  • EP2677546B1 patent drawingFigure 3a~3c

AI summary

A method for manufacturing a dopant layer of a solar cell according to an embodiment of the invention includes: ion-implanting a dopant to a substrate; and heat-treating for an activation of the dopant. In the heat-treating for the activation, the substrate is heat-treated at a first temperature after an anti-out-diffusion film is formed at a temperature lower than the first temperature under a first gas atmosphere.