Solar Cell Doped Layer Layout for Selective Ohmic Contact

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Solution Overview

Problem

In solar cell manufacturing, the contact between the electrode and the lightly doped region affects substrate passivation, leading to reduced performance.

Innovation Solution

A solar cell design with a doped layer having a heavily doped region, edge regions, and connecting regions, where the electrode forms an ohmic contact only with the heavily doped region, optimizing doping concentrations and junction depths to improve passivation and reduce carrier recombination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the doped layer structure is simplified to reduce manufacturing complexity, then manufacturing precision may deteriorate due to inadequate electrode-doped layer alignment

Engineering Contradiction:
Improvedoped layer structureVSAvoidelectrode-doped layer alignment
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The doped layer is divided into regions with different doping concentrations (heavily doped regions and lightly doped regions) to optimize both electrical performance and manufacturing alignment. The heavily doped regions provide clear visual markers for alignment while maintaining overall device functionality.

Inventive Principle:
Principle #3Local quality

2Reliability

If the doped layer is uniformly heavily doped to improve electrical contact, then optical absorption increases reducing light utilization efficiency

Engineering Contradiction:
Improveelectrical contactVSAvoidoptical absorption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Different regions of the doped layer have different doping concentrations optimized for their specific functions. Heavily doped regions under electrodes provide excellent electrical contact, while lightly doped regions in between minimize optical absorption and maximize light utilization for charge generation.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If the doped layer is uniformly lightly doped to reduce optical absorption, then electrical contact deteriorates

Engineering Contradiction:
Improveoptical absorptionVSAvoidelectrical contact
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The doped layer employs spatially varying doping concentrations where heavily doped regions are positioned at electrode interfaces to ensure low resistance electrical contact, while lightly doped regions are positioned in areas where light absorption should be minimized, thus simultaneously optimizing both electrical and optical performance.

Inventive Principle:
Principle #3Local quality

4Manufacturing precision

If the doped layer structure is made complex to improve alignment precision, then manufacturing complexity increases

Engineering Contradiction:
Improveelectrode-doped layer alignmentVSAvoiddoped layer structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The doped layer uses regions of different doping concentrations that create distinct visual or electrical signatures during manufacturing, enabling precise alignment of electrodes with underlying doped regions without requiring overly complex structural features. The varying doping profiles provide inherent alignment cues.

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 enhances the open-circuit voltage, fill factor, and conversion efficiency of the solar cell by improving the ohmic contact and passivation on the substrate surface.

Implementation Method 1

the heavily doped region can provide spaces more than spaces corresponding to the connecting electrodes and the edge electrodes, that is, the heavily doped region may provide a space-charge limited current transport mechanism to improve charge extraction efficiency

Methodology Applied
Scientific EffectSpace-charge limited current:

Implementation Method 2

Solar cell and manufacturing method thereof, photovoltaic module and photovoltaic system

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4421883A2Solar cell and manufacturing method thereof, photovoltaic module and photovoltaic system
Publication Date: 2024.08.28 TRINA SOLAR CO LTD
  • EP4421883A2 patent drawingFigure 1~2
  • EP4421883A2 patent drawingFigure 3
  • EP4421883A2 patent drawingFigure 4

AI summary

The present disclosure relates to the technical field of solar cells, and in particular, to a solar cell and a manufacturing method thereof, a photovoltaic module and a photovoltaic system. In the embodiment of the present disclosure, a doped layer of the solar cell includes a lightly doped region and a heavily doped region, the heavily doped region includes a body region, connecting regions, and edge regions, and an electrode includes an electrode body, connecting electrodes and edge electrodes. The body region substantially corresponds to the electrode body, and the connecting regions and the edge regions can provide spaces more than spaces corresponding to the connecting electrodes and the edge electrodes.