Solar Cell Recombination Layer for Carrier Extraction

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Solution Overview

Problem

The existing back contact solar cell configuration struggles to improve solar cell characteristics due to the electric field formed by the n-type semiconductor layer on the p-type semiconductor layer, leading to difficulties in carrier collection and efficiency.

Innovation Solution

Incorporating a recombination layer with many in-gap levels or a metal material for ohmic contact between the p-type and n-type amorphous semiconductor layers, along with a thin i-type amorphous semiconductor layer, to reduce resistance and inhibit opposite electric field formation, thereby enhancing carrier extraction and solar cell performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an n-type semiconductor layer is formed on a p-type semiconductor layer, then the manufacturing process is simplified, but an opposite electric field is formed that deteriorates solar cell characteristics

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidsolar cell characteristic
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A recombination layer is introduced as an intermediary between the n-type and p-type semiconductor layers. This recombination layer has many in-gap levels that facilitate carrier recombination and prevent the formation of an opposite electric field, thereby resolving the contradiction between manufacturing simplicity and solar cell performance

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The conductivity type of the semiconductor layer is changed from n-type to intrinsic or weakly p-type in the region contacting the p-type layer. This parameter change prevents the formation of an opposite electric field while maintaining the simplified manufacturing process

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If a recombination layer with many in-gap levels is introduced, then carrier collection loss is reduced, but device complexity increases

Engineering Contradiction:
Improvecarrier collection lossVSAvoidlayer structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The recombination layer is formed by changing the conductivity type parameter of the semiconductor layer to intrinsic or weakly p-type, rather than introducing a completely new material layer. This reduces device complexity while still providing the necessary in-gap levels for carrier recombination

Inventive Principle:
Principle #35Parameter changes

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 solution effectively reduces carrier collection loss and improves solar cell characteristics by facilitating low-resistance contact and efficient carrier extraction, leading to enhanced solar cell performance without increasing manufacturing costs.

Implementation Method 1

a recombination layer having many in-gap levels or a metal material in an ohmic contact with the p-type amorphous semiconductor layer

Methodology Applied
Scientific EffectIn-gap levels:

Implementation Method 2

a recombination layer having many in-gap levels or a metal material in an ohmic contact with the p-type amorphous semiconductor layer

Methodology Applied
Scientific EffectOhmic contact:

Implementation Method 3

Solar cells can convert sunlight, which is clean and is available in unlimited amounts, directly into electricity

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP2403004B1Solar cell
Publication Date: 2021.03.31 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2403004B1 patent drawingFigure 1
  • EP2403004B1 patent drawingFigure 2
  • EP2403004B1 patent drawingFigure 3

AI summary

A solar cell (100) includes a p-type amorphous semiconductor layer (11p), an n-type amorphous semiconductor layer (12n), and a recombination layer (R) interposed between the p-type amorphous semiconductor layer (11p) and the n-type amorphous semiconductor layer (12n).