Solar Cell Electrode Wraparound Design for Short-Circuit Prevention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing solar cell manufacturing methods face challenges such as short-circuiting and leakage due to wraparound of thin-films, leading to power generation losses and decreased module performance, particularly when forming electrodes without masks results in reduced carrier collection efficiency and effective power generation area.

Innovation Solution

A solar cell design featuring a photoelectric conversion section with an n-type crystalline silicon substrate, where p-type and n-type silicon-based thin-films are formed on both surfaces, and a transparent first electrode layer and a second electrode layer are deposited without using a mask, with the second electrode layer extending in a wraparound manner to cover the peripheral portion, creating an insulating region and preventing short-circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mask is used to cover the peripheral portion during thin-film deposition to prevent short-circuit, then short-circuit prevention is improved, but positioning accuracy deteriorates and productivity decreases

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidproductivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The harmful wraparound effect is eliminated by extracting the thin-film deposition from the peripheral region through selective area deposition. The patent uses a mask that covers only the immediate edge region while allowing deposition on the rest of the surface, thereby preventing short-circuit without requiring complete peripheral coverage or repositioning operations.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If the peripheral portion is cleaved and removed to form a cut surface, then short-circuit is prevented, but the area of silicon substrate decreases and current amount reduces

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidcurrent amount

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating different structural characteristics in different regions of the solar cell. The peripheral portion retains the thin-film structure for carrier collection, while the immediate edge region is protected from deposition. This localized differentiation prevents short-circuit while preserving the photoelectric conversion function in the peripheral regions.

Inventive Principle:

Principle #3Local quality

3Reliability

If a separation groove is formed by laser irradiation, then short-circuit is prevented, but the outer periphery of the separation groove cannot be used as effective power generation area and current amount decreases

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidcurrent amount

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements preliminary action by pre-defining the deposition pattern through mask design before the deposition process begins. The mask is configured to prevent thin-film formation only in the immediate edge region where short-circuit would occur, while allowing deposition in all other regions including the outer periphery that would otherwise be affected by laser grooving. This preliminary spatial control eliminates the need for post-deposition groove formation.

Inventive Principle:

Principle #10Preliminary action

4Productivity

If thin-film is deposited without mask on peripheral portion, then carrier collection efficiency is improved, but short-circuit and leakage occur

Engineering Contradiction:

Improvecarrier collection efficiencyVSAvoidleakage prevention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Inventive Principle:

Principle #3Local quality

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 effectively prevents short-circuits and mechanical damage during modularization, enhancing carrier collection efficiency and module performance by reducing leakage currents and maintaining high conversion characteristics.

Implementation Method 1

thin-films such as a semiconductor layer, a transparent electrode layer and a metal electrode are generally formed on the silicon substrate surface by a dry process such as a plasma-enhanced CVD method, a sputtering method or the like

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

an electrode is provided on a photoelectric conversion section for efficiently extracting carriers, which are generated in the photoelectric conversion section having a semiconductor junction

Methodology Applied

Scientific EffectPhotovoltaic Effect: Photovoltaic Effect

Data Source

PatentUS10453981B2Solar cell, solar cell module, method for manufacturing solar cell, and method for manufacturing solar cell module

Publication Date: 2019.10.22 KANEKA CORP

AI summary

A solar cell includes a photoelectric conversion section that, includes an n-type crystal silicon substrate, a p-type silicon-based thin-film provided on a first principal surface, and an n-type silicon-based thin-film provided on a second principal surface, and further includes a first electrode layer on the p-type silicon-based thin-film, and a second electrode layer on the n-type silicon-based thin film. A patterned collector electrode is provided on the first electrode layer. On the first principal surface of the photoelectric conversion section, a wraparound portion of the second electrode layer, an insulating region where neither the first electrode layer nor the second electrode layer is provided, and a first electrode layer-formed region are arranged in this order from a peripheral end.