Solar Cell Boundary Region Doping for Efficiency

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Solution Overview

Problem

Current solar cell designs face inefficiencies due to the limited design of various layers and electrodes, which hampers their widespread adoption as a next-generation alternative energy source.

Innovation Solution

A solar cell design featuring semiconductor substrates with strategically formed first and second conductivity type regions, including varying doping concentrations and depths, where the first conductivity type region has a wider boundary region than the second, optimized through ion implantation and activated heat treatment, to maximize the photoelectric conversion area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional solar cell designs with uniform doping are used, then manufacturing is simpler, but photoelectric conversion efficiency is limited

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

Solution Approach 1:

The patent applies local quality by creating boundary regions with varying doping concentrations specifically at the peripheral portions of conductivity type regions. The doping concentration varies from a first concentration in the main region to a second concentration in the boundary region, optimizing electrical properties locally where they are most needed for charge carrier collection while maintaining simpler uniform doping in the main regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments each conductivity type region into two distinct parts: a main region with uniform doping and a boundary region with varying doping concentration. This segmentation allows different doping strategies to be applied to different functional zones, enhancing overall device performance while maintaining manufacturing feasibility through systematic process design.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the photoelectric conversion area is increased, then energy conversion efficiency improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoiddoping concentration control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent utilizes parameter changes by varying the doping concentration from a first concentration in the main regions to a second concentration in the boundary regions. This parameter variation is achieved through controlled diffusion processes where the doping concentration naturally gradients from high to low, simplifying the manufacturing precision requirements compared to maintaining uniform high doping throughout.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary action by forming the doping structure through a diffusion process that naturally creates the concentration gradient before device operation. The varying doping concentration is established in advance through thermal diffusion or ion implantation followed by annealing, creating the desired profile without requiring precise real-time control during manufacturing.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If boundary regions with varying doping are formed, then charge carrier collection is improved, but manufacturing process complexity increases

Engineering Contradiction:
Improvecharge carrier collectionVSAvoidmanufacturing process steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the formation of boundary regions with the existing doping工艺流程 by using the same diffusion or ion implantation processes that create the main conductivity type regions. The varying doping concentration in boundary regions is achieved as a natural extension of the doping process, combining multiple functions into a unified manufacturing approach rather than adding separate process steps.

Inventive Principle:
Principle #5Merging (Combining)

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 efficiency of solar cells by increasing the size of the conductivity type regions participating in photoelectric conversion, leading to improved energy conversion efficiency and simplified manufacturing processes.

Implementation Method 1

optimized through ion implantation and activated heat treatment

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Implementation Method 2

optimized through ion implantation and activated heat treatment

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

solar cells, which directly convert solar energy into electric energy

Methodology Applied
Scientific EffectPhotoelectric conversion: Photovoltaic Effect

Data Source

PatentEP2879189B1Solar cell and method of manufacturing the same
Publication Date: 2020.05.27 LG ELECTRONICS INC
  • EP2879189B1 patent drawingFigure 1
  • EP2879189B1 patent drawingFigure 2
  • EP2879189B1 patent drawingFigure 3

AI summary

A solar cell is discussed. The solar cell according to an embodiment includes a semiconductor substrate, a first conductivity type region and a second conductivity type region disposed on the same side of the semiconductor substrate, wherein at least one of the first and second conductivity type regions includes a main region and a boundary region disposed at a peripheral portion of the main region, and the boundary region has at least one of a varying doping concentration and a varying doping depth.