Solar Cell PID Resistance via Plasma Oxide Passivation

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Solution Overview

Problem

Conventional solar cell manufacturing processes lead to potential induced degradation (PID) in photovoltaic modules, causing reduced electrical performance under high negative voltage due to leakage currents between packaging materials and glass substrates, which are not effectively addressed by existing methods that increase costs with high-resistance packaging materials.

Innovation Solution

A method involving plasma cleaning of silicon wafers with oxidizing gases to form a compact silicon oxide film, followed by depositing a multi-layer anti-reflection film comprising silicon oxide and nitride films using PECVD, APCVD, or LPCVD, enhancing electrical insulation and reducing PID effects without the need for special packaging materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional solar cell manufacturing processes are used, then production cost is reduced, but potential induced degradation occurs causing reduced electrical performance under high negative voltage

Engineering Contradiction:
Improveelectrical performance stabilityVSAvoidpotential induced degradation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A passivation film is formed on the rear surface of the silicon wafer before assembling the photovoltaic module. This preliminary protective layer prevents charge accumulation and leakage current during module operation under high negative voltage, thereby preventing potential induced degradation before it can occur.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The passivation film acts as an intermediary layer between the silicon wafer and the external environment (packaging materials, glass substrate). This intermediate layer blocks the harmful electrical interaction between the silicon and surrounding materials, preventing charge leakage and maintaining electrical performance stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If high-resistance packaging materials are used to prevent leakage current, then PID resistance is improved, but production cost increases

Engineering Contradiction:
ImprovePID resistanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The solution extracts the PID protection function from the packaging materials and transfers it to a dedicated passivation film on the silicon wafer. This allows the use of conventional, cost-effective packaging materials while maintaining PID resistance through the separate, specialized protective layer.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using expensive special packaging materials, a thin, inexpensive passivation film is applied directly to the silicon wafer surface. This low-cost protective layer provides the necessary PID protection without requiring costly changes to the packaging materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

The method improves the electrical performance of photovoltaic modules by preventing leakage currents and reducing PID, maintaining performance under high negative voltage while keeping production costs low and being compatible with conventional processes for large-scale production.

Implementation Method 1

performing plasma cleaning on a silicon wafer by using an oxidizing gas

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 2

form a first silicon oxide film on the surface of the silicon wafer

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

depositing a uniform silicon nitride film on the surface of the first silicon oxide film, and depositing a uniform silicon oxide film on the surface of the silicon nitride film

Methodology Applied
Scientific EffectPlasma enhanced chemical vapor deposition: Plasma Enhanced Chemical Vapour Deposition

Data Source

PatentEP2782146B1Method for manufacturing a solar cell with reduced potential induced degradation
Publication Date: 2016.10.12 JINKOSOLAR HLDG
  • EP2782146B1 patent drawingFigure 1~2
  • EP2782146B1 patent drawingFigure 3~5
  • EP2782146B1 patent drawingFigure 6~7

AI summary

A solar cell with reduced potential induced degradation and a manufacturing method thereof are disclosed. The method includes: performing plasma cleaning on a silicon wafer (100) by using an oxidizing gas, so as to form a first silicon oxide film (101) on the surface of the silicon wafer; and forming an anti-reflection film (20) on the surface of the first silicon oxide film, where the anti-reflection film (20) includes at least a silicon oxide film (20, 200, 201, 203). Since the silicon oxide film has a good electrical insulation property and an anti-reflection effect, the solar cell manufactured by using the manufacturing method according to the embodiments of the invention has a good electrical insulation property with the packaging material, the glass substrate and so on, so the corresponding photovoltaic module has an anti potential induced degradation effect, which improves the electrical performance of the photovoltaic module operating under the high negative voltage for a long time.