Solar Cell Contact Layout for Carrier Transfer and Light Absorption

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Solution Overview

Problem

Existing solar cells with passivation contact structures face issues of parasitic light absorption and reduced transverse carrier transfer efficiency due to the thickness of the doped conductive layer, which affects the overall performance.

Innovation Solution

The solar cell design incorporates a doped conductive layer with protrusions and conductive connection structures between adjacent protrusions, allowing for improved transverse carrier transfer and reduced parasitic light absorption by forming a relatively thick doped conductive layer where finger electrodes are present and a thin layer between them, along with conductive connection structures to facilitate carrier transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a doped conductive layer is used to improve carrier transfer capacity, then carrier transfer efficiency is improved, but parasitic absorption of light increases reducing photoelectric conversion efficiency

Engineering Contradiction:
Improvecarrier transfer efficiencyVSAvoidparasitic absorption of light
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The doped conductive layer is segmented into multiple regions with different doping concentrations. The first region (near the interface) has higher doping concentration to enhance carrier transfer, while the second region (deeper in the substrate) has lower doping concentration to reduce parasitic absorption. This spatial segmentation allows simultaneous optimization of both carrier transfer efficiency and light absorption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the doped conductive layer are assigned different local properties (doping concentrations) to fulfill different functional requirements. The high-doping region provides excellent carrier transfer capability where it is most needed, while the low-doping region minimizes parasitic absorption in areas where light absorption is critical.

Inventive Principle:
Principle #3Local quality

2Reliability

If the doped conductive layer thickness is increased to improve carrier transfer, then carrier transfer capacity is enhanced, but light absorption is reduced due to increased parasitic absorption

Engineering Contradiction:
Improvecarrier transfer capacityVSAvoidlight utilization
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The doped conductive layer is divided into depth segments with varying doping concentrations. By segmenting the layer in the depth direction, the patent achieves sufficient carrier transfer capacity through the high-doping first region while the low-doping second region allows light to pass through with minimal parasitic absorption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The doping concentration parameter is changed spatially within the doped conductive layer. The first region maintains high doping concentration for carrier transfer, while the second region uses lower doping concentration to reduce parasitic absorption. This parameter variation with depth optimizes both carrier transfer and light utilization.

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

This design enhances the transverse transferring capacity and reduces parasitic light absorption, leading to improved photoelectric conversion efficiency and open-circuit voltage.

Implementation Method 1

cells with a passivation contact structure of at least one tunneling oxide layer

Methodology Applied
Scientific EffectQuantum tunneling:

Implementation Method 2

Solar cells are used to convert solar energy into electrical energy

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4300599A1Solar cell and photovoltaic module
Publication Date: 2024.01.03 ZHEJIANG JINKO SOLAR CO LTD
  • EP4300599A1 patent drawingFigure 1~2
  • EP4300599A1 patent drawingFigure 3~4
  • EP4300599A1 patent drawingFigure 5~6

AI summary

Embodiments of the present disclosure relate to the photovoltaic field, and provide a solar cell and a photovoltaic module. The solar cell includes a substrate, a tunneling dielectric layer formed on the substrate, a doped conductive layer formed on the tunneling dielectric layer, at least one conductive connection structure, a passivation layer over the doped conductive layer and the at least one conductive connection structure, and a plurality of finger electrodes. The doped conductive layer has a plurality of protrusions arranged along a first direction, and each protrusion extends along a second direction perpendicular to the first direction. The at least one conductive connection structure is formed between two adjacent protrusions and connected with sidewalls of the two adjacent protrusions. Each finger electrode of the plurality of finger electrodes extends along the second direction to penetrate the passivation layer and connect to a respective protrusion. Embodiments of the present disclosure can at least improve performance of solar cells.