Tunnel Oxide Solar Cell Layout for Lower Carrier Recombination

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Solution Overview

Problem

Current solar cell technologies face limitations in achieving high photoelectric conversion efficiency, despite advancements in types such as PERC, TOPCON, HIT, and IBC cells.

Innovation Solution

A solar cell design featuring a substrate with specific passivation and doped layers, insulating layers, and trench structures, including a first and second region configuration with isolation trenches and transparent conductive layers, optimized for improved carrier collection and reduced recombination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional solar cell structures (PERC, TOPCON, HIT, IBC) are used, then manufacturing and basic functionality are maintained, but photoelectric conversion efficiency is limited and cannot achieve higher levels

Engineering Contradiction:
Improvephotoelectric conversion efficiencyVSAvoidlayer structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The solar cell structure is divided into distinct functional regions: a first region with a first doped layer and tunnel oxide layer for one type of carrier collection, and a second region with a second doped layer for another type of carrier collection. This segmentation allows each region to be optimized for specific carrier types, improving overall photoelectric conversion efficiency while maintaining manageable structural complexity through clear functional zoning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the solar cell are assigned different doping types and layer configurations tailored to local functional requirements. The first region uses a first doped layer with specific doping characteristics optimized for collecting one carrier type, while the second region uses a second doped layer optimized for collecting the opposite carrier type. This local optimization of material properties and structure enhances carrier collection efficiency without requiring complete redesign of the entire cell structure.

Inventive Principle:
Principle #3Local quality

2Productivity

If isolation trenches are added to improve carrier collection, then photoelectric conversion efficiency increases, but manufacturing complexity and process difficulty increase

Engineering Contradiction:
Improvecarrier collection efficiencyVSAvoidtrench fabrication complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

Isolation trenches are formed in advance during the manufacturing process, before subsequent layer deposition steps. By pre-defining the trench structures that separate different doped regions, the patent enables better control over carrier collection paths and reduces cross-contamination between regions. This preliminary structuring simplifies later processing steps and improves overall manufacturing efficiency despite the added initial complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The isolation trenches act as intermediary structures that physically separate and electrically isolate the first doped layer region from the second doped layer region. These trenches serve as mediators that prevent unwanted carrier recombination between adjacent doped regions while maintaining clear functional boundaries. The trench structures facilitate controlled carrier transport paths, improving collection efficiency without requiring direct contact between opposing doped layers.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enhances photoelectric conversion efficiency by minimizing carrier recombination and optimizing light utilization through tailored layer structures and trench configurations.

Implementation Method 1

the photoelectric conversion efficiency of solar cells has gradually increased

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 2

a first doped layer and a tunnel oxide layer sequentially stacked in the first region

Methodology Applied
Scientific EffectTunneling effect:

Data Source

PatentEP4462486A1Solar cell and photovoltaic module
Publication Date: 2024.11.13 TRINA SOLAR CO LTD
  • EP4462486A1 patent drawingFigure 1A~1B
  • EP4462486A1 patent drawingFigure 1C~1D
  • EP4462486A1 patent drawingFigure 1E~1F

AI summary

A solar cell is provided. The solar cell comprises: a substrate having a first surface and a second surface opposite to each other, the second surface having a first region and a second region adjacent in a first direction; a first passivation layer located on the first surface; a first doped layer and a tunnel oxide layer sequentially stacked in the first region; a first insulating layer located on a surface of the first doped layer away from the substrate; a second passivation layer located in the second region and extending to a surface of the first insulating layer away from the substrate; a second doped layer located on a surface of the second passivation layer away from the substrate; and a second insulating layer located between the second passivation layer and the first doped layer, and between the second passivation layer and the tunnel oxide layer in the first direction, wherein a side of the second insulating layer away from the substrate is in contact with the first insulating layer. The solar cell in the present application uses the tunnel oxide layer and the doped polycrystalline silicon layer to passivate the solar cell, which improves the photoelectric conversion efficiency of the cells