Passivated Solar Cell Electrodes With 3D Sidewall Contact

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Solution Overview

Problem

Conventional solar cells have low photoelectric conversion efficiency due to limited electrode-carrier contact area and parasitic absorption by passivation contact structures, which reduces light utilization and increases direct contact with the substrate, leading to carrier recombination.

Innovation Solution

A solar cell design with first and second passivation contact structures and electrodes that cover the top surface and sidewalls of these structures, enhancing electrical contact and reducing parasitic absorption by aligning passivation contact structures with electrodes, thereby improving carrier collection and avoiding direct contact with the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If electrodes are formed to collect carriers from passivation contact structures, then carrier collection ability is improved, but contact area between electrodes and passivation contact structures is limited

Engineering Contradiction:
Improvecarrier collection abilityVSAvoidcontact area between electrode and passivation contact structure
Core Design Contradiction:
ProductivityVSArea of moving object

Solution Approach 1:

The electrode structure transitions from a planar configuration to a three-dimensional configuration by extending along the sidewalls of the passivation contact structures. This vertical extension into the depth dimension significantly increases the contact area between the electrode and the passivation contact structure, thereby improving carrier collection ability without occupying additional horizontal space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The electrode is designed to wrap around and enclose the passivation contact structure, with the electrode material forming a nested configuration where the passivation contact structure is positioned within the electrode's three-dimensional structure. This nesting arrangement maximizes the interfacial contact area between the electrode and passivation contact structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Loss of energy

If passivation contact structures are positioned to reduce parasitic absorption, then light utilization is improved, but direct contact with substrate may occur leading to carrier recombination

Engineering Contradiction:
Improveparasitic absorptionVSAvoidcarrier recombination
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The passivation contact structure serves as an intermediary layer positioned between the electrode and the substrate. This intermediate structure provides electrical contact for carrier collection while simultaneously passivating the substrate surface to prevent direct contact between the electrode and substrate, thereby reducing carrier recombination losses.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The passivation contact structure is strategically positioned in specific regions where it can simultaneously achieve two functions: reducing parasitic absorption by being located in optically favorable positions, and preventing carrier recombination by providing a passivated interface between the electrode and substrate in electrically critical regions.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If electrode structure is simplified for ease of manufacture, then manufacturing complexity is reduced, but contact area and carrier collection ability are limited

Engineering Contradiction:
Improveelectrode fabrication simplicityVSAvoidelectrode contact area
Core Design Contradiction:
Ease of manufactureVSArea of moving object

Solution Approach 1:

The electrode structure is designed with flexible geometry that can adapt to the contours of the passivation contact structures. The electrode material can be deposited in a way that naturally conforms to the underlying structure, creating the three-dimensional sidewall contact configuration without requiring complex multi-step alignment processes.

Inventive Principle:
Principle #15Dynamics

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 design increases the contact area between electrodes and passivation contact structures, enhancing carrier collection and reducing parasitic absorption, thus improving photoelectric conversion efficiency and light utilization while preventing substrate contact.

Implementation Method 1

a passivation contact structure is prepared on one of the surfaces of the substrate for inhibiting carrier recombination on the surface of the substrate in the solar cell and providing good conductivity for majority carriers

Methodology Applied
Scientific EffectPassivation:

Implementation Method 2

The electrodes are in electrical contact with the passivated contact structure to collect the carriers

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

Solar cells have good photovoltaic conversion capabilities

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4579761A1Solar cell, method for preparing solar cell, and photovoltaic module
Publication Date: 2025.07.02 ZHEJIANG JINKO SOLAR CO LTD
  • EP4579761A1 patent drawingFigure 1~2
  • EP4579761A1 patent drawingFigure 3~4
  • EP4579761A1 patent drawingFigure 5~6

AI summary

A solar cell is provided, including: a substrate having a first surface including first regions and second regions, a first passivation contact structure formed on the first and second regions, second passivation contact structures formed on the first passivation contact structure, first passivation films formed on the first passivation contact structure, and first electrodes extending in a second direction perpendicular to the first direction. Each second passivation contact structure has an orthographic projection on the first surface in a respective first region, and each first passivation film has an orthographic projection on the first surface in a respective second region. Each first electrode covers a top surface of a respective second passivation contact structure and at least part of two opposing sidewalls of the respective second passivation contact structure in the first direction, and is in electrical contact with the respective second passivation contact structure.