Passivated Contact Solar Cell Doping Layout for Lower Recombination

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Solution Overview

Problem

Existing passivated contact solar cells suffer from low photoelectric conversion efficiency due to inhomogeneous doping concentration and overlapping heavily doped areas formed during laser doping, leading to increased contact resistance and recombination losses.

Innovation Solution

The solar cell design includes sets of heavily doped areas divided into first and second heavily doped areas, with the second areas formed by diffusion around the first, ensuring homogeneous doping and reducing overlapping, coupled with electrodes contacting only the first areas to form a good ohmic contact, thereby improving doping homogeneity and productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If laser doping is used to form heavily doped areas, then doping productivity is improved, but inhomogeneous doping concentration and overlapping heavily doped areas occur leading to increased contact resistance

Engineering Contradiction:

Improvedoping productivityVSAvoiddoping concentration uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The heavily doped area is segmented into a first heavily doped area and a second heavily doped area. The first heavily doped area is formed by laser doping with controlled energy parameters to avoid overlapping, while the second heavily doped area is formed by diffusion around the first area. This segmentation allows the laser doping process to be more precise and controlled, reducing inhomogeneous doping concentration and overlapping issues, thereby maintaining high doping productivity while improving doping concentration uniformity.

Inventive Principle:

Principle #1Segmentation

2Reliability

If heavily doped areas are formed to reduce contact resistance, then electrical conductivity is improved, but overlapping heavily doped areas increase recombination losses

Engineering Contradiction:

Improvecontact resistanceVSAvoidrecombination losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating distinct first and second heavily doped areas with different formation mechanisms and properties. The first heavily doped area provides low contact resistance through direct laser doping, while the second heavily doped area formed by diffusion around it reduces recombination losses by creating a gradient doping profile. This local differentiation of doping quality optimizes both electrical conductivity and energy efficiency.

Inventive Principle:

Principle #3Local quality

3Speed

If conventional laser doping is used, then doping speed is high, but overlapping heavily doped areas reduce photoelectric conversion efficiency

Engineering Contradiction:

Improvedoping speedVSAvoidphotoelectric conversion efficiency

Core Design Contradiction:

SpeedVSProductivity

Solution Approach 1:

The patent implements preliminary action by first forming the first heavily doped area through controlled laser doping, then subsequently forming the second heavily doped area through diffusion around the first area. This sequential approach ensures that the laser doping does not create overlapping heavily doped areas that would reduce photoelectric conversion efficiency, while still maintaining high doping speed through the efficient laser process for the first area.

Inventive Principle:

Principle #10Preliminary action

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 photoelectric conversion efficiency by reducing contact resistance and recombination losses, while increasing doping productivity and uniformity, thus improving the overall performance of the solar cells.

Implementation Method 1

This structure can provide good surface passivation, thereby reducing recombination current at metal contact

Methodology Applied

Scientific EffectSurface passivation:

Implementation Method 2

each of the plurality of electrodes contacts with at least part of each set of heavily doped areas of the doped conductive layer

Methodology Applied

Scientific EffectOhmic contact:

Implementation Method 3

the doped conductive layer includes a doping element of a same type as that of the doping element in the substrate, and the doped conductive layer further includes a plurality of sets of heavily doped areas

Methodology Applied

Scientific EffectHeavy doping: Dopants

Data Source

PatentUS12598835B2Solar cell and production method thereof, photovoltaic module

Publication Date: 2026.04.07 ZHEJIANG JINKO SOLAR CO LTD

AI summary

Embodiments of the present disclosure provide a solar cell and a production method thereof, and a photovoltaic module. The solar cell includes: a substrate; a tunnel dielectric layer, located on a surface of the substrate; a doped conductive layer, located on a surface of the tunnel dielectric layer away from the substrate, the doped conductive layer includes a doping element of a same type as a doping element of the substrate, and a plurality of sets of heavily doped areas, the sets includes first heavily doped areas and second heavily doped areas extending in a first direction and arranged at intervals in a second direction; and a plurality of electrodes arranged at intervals, the electrodes extend in the second direction and correspond to the sets, and the electrodes contact with at least part of each sets. The present disclosure can improve photoelectric conversion efficiency of the solar cell.