Solar Cell Electrode Lattice for Large-Area Sheet Resistance

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Solution Overview

Problem

Existing thin-film solar cells face a significant decrease in power conversion efficiency as the device area increases due to high sheet resistance, which limits the development of efficient large-area solar cells.

Innovation Solution

The use of a combination electrode structure comprising a conductive layer and a conductive lattice in solar cells, where the conductive lattice has higher conductivity than the conductive layer, reduces overall sheet resistance, allowing for efficient photocurrent collection and transfer, thereby mitigating the impact of sheet resistance on efficiency across larger areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the device area is increased to meet application requirements, then the coverage and power output are improved, but the sheet resistance increases significantly causing efficiency to deteriorate

Engineering Contradiction:
Improvedevice areaVSAvoidphotoelectric conversion efficiency
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The electrode is divided into a conductive layer and a conductive lattice structure. The conductive lattice consists of interconnected conductive elements forming a network that spans the large area, while the conductive layer provides additional conductivity pathways. This segmentation allows the electrode to maintain low sheet resistance across large areas by distributing current through multiple parallel conductive pathways.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode uses a composite structure combining a conductive layer (such as transparent conductive oxide) with a conductive lattice (made of metal nanowires, carbon nanotubes, or other highly conductive materials). This composite approach leverages the advantages of both materials: the transparency and flexibility of the conductive layer and the high conductivity of the conductive lattice, achieving low sheet resistance while maintaining optical properties.

Inventive Principle:
Principle #40Composite materials

2Device complexity

If a single conductive layer is used to simplify the structure, then the device complexity is reduced, but the sheet resistance increases causing efficiency loss

Engineering Contradiction:
Improveelectrode structureVSAvoidefficiency loss due to sheet resistance
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The electrode merges two distinct conductive components: a conductive layer and a conductive lattice. These components work together synergistically, with the conductive lattice providing high conductivity pathways and the conductive layer offering additional conduction routes and optical transparency. The merged structure achieves lower sheet resistance than either component alone would provide.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The conductive lattice is strategically positioned and configured with varying local densities and patterns to optimize conductivity where needed. The lattice structure can be adjusted to have higher conductivity in regions with greater current density requirements, while maintaining overall structural simplicity and compatibility with the conductive layer.

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 approach significantly reduces the overall sheet resistance of the electrodes, improving photoelectric conversion efficiency and enabling the development of large-area solar cells with enhanced performance.

Implementation Method 1

the first conductive layer is configured to receive a photocurrent generated by the functional layer, and the first conductive lattice is configured to output the photocurrent to a target device

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a solar cell includes a first electrode, a second electrode, and a functional layer that is connected between the first electrode and the second electrode

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4095936B1Solar cell, method for preparing same, smart glasses, and electronic device
Publication Date: 2024.01.31 HUAWEI TECH CO LTD
  • EP4095936B1 patent drawingFigure 1~2
  • EP4095936B1 patent drawingFigure 3
  • EP4095936B1 patent drawingFigure 4

AI summary

This application provides a solar cell, a method for preparing the solar cell, smart glasses, and an electronic device. The solar cell includes a first conductive layer, a second conductive layer, a first conductive lattice, a second conductive layer, and a functional layer. The functional layer is disposed between the first conductive layer and the second conductive layer, the functional layer is configured to absorb light and generate a photocurrent, and both the first conductive layer and the second conductive layer are configured to receive the photocurrent. The first conductive lattice is in contact with a surface that is of the first conductive layer. The second conductive lattice is in contact with the second conductive layer, and the first conductive lattice and the second conductive lattice are configured to output the photocurrent to the target device. This application can mitigate impact of a sheet resistance on cell efficiency.