Laser-Crystallized Polysilicon Solar Cell Layers for Simpler Passivation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing process for preparing solar cells is complicated due to the need to form multiple doped polysilicon layers with different degrees of crystallization, which requires multiple steps and increases the complexity of the overall process.

Innovation Solution

A method involving the formation of a doped amorphous silicon layer on a substrate, followed by multiple laser treatments to create multiple doped polysilicon layers with varying degrees of crystallization, simplifying the process by reducing the number of steps required to achieve multiple crystallization levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple doped polysilicon layers with different degrees of crystallization are formed using conventional methods, then photoelectric conversion performance is improved, but the overall process complexity increases

Engineering Contradiction:
Improvephotoelectric conversion performanceVSAvoidoverall process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate processes for forming different doped polysilicon layers into a single integrated laser treatment process. By using selective laser irradiation with different parameters (power, pulse duration, wavelength) on a single doped amorphous silicon layer, multiple polysilicon layers with different crystallization degrees are formed simultaneously, thereby simplifying the overall manufacturing process while maintaining photoelectric conversion performance

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes laser treatment parameters (power, pulse duration, wavelength) to control the crystallization degree of polysilicon layers formed from a single doped amorphous silicon layer. By adjusting these parameters, different regions of the same layer achieve different levels of crystallization, creating multiple functional layers without requiring multiple separate deposition processes

Inventive Principle:
Principle #35Parameter changes

2Reliability

If multiple separate doped polysilicon layers are formed using conventional methods, then field passivation effect is enhanced, but the number of process steps increases

Engineering Contradiction:
Improvefield passivation effectVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent uses periodic laser pulse irradiation to treat the doped amorphous silicon layer, where different pulse durations and power levels create sequential crystallization zones. This periodic action with varying parameters enables the formation of multiple polysilicon layers with different crystallization degrees in a single continuous process, enhancing field passivation while improving production efficiency

Inventive Principle:
Principle #19Periodic 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 approach simplifies the solar cell preparation process, facilitates mass production, and enhances photoelectric conversion performance by allowing different doped polysilicon layers to play distinct roles, thereby improving the solar cell's efficiency.

Implementation Method 1

performing a laser treatment N times on the doped amorphous silicon layer to form N doped polysilicon layers

Methodology Applied
Scientific EffectLaser irradiation: Laser

Implementation Method 2

a grain size of the n th doped polysilicon layer is larger than a grain size of the n-1 th doped polysilicon layer

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Implementation Method 3

doped with conductive ions to form an energy band bending on a surface of the substrate, thereby playing a field passivation effect on minority carriers

Methodology Applied
Scientific EffectField passivation:

Data Source

PatentEP4293729A1Method for preparing solar cell and solar cell, photovoltaic module
Publication Date: 2023.12.20 ZHEJIANG JINKO SOLAR CO LTD
  • EP4293729A1 patent drawingFigure 1~3
  • EP4293729A1 patent drawingFigure 4~6
  • EP4293729A1 patent drawingFigure 7~9

AI summary

Embodiments of the present application relate to the technical field of solar cells, and in particular, to a method for preparing a solar cell, the solar cell, and a photovoltaic module. The method for preparing the solar cell includes: providing a substrate; forming a doped amorphous silicon layer on a side of a first surface of the substrate; performing a laser treatment N times on the doped amorphous silicon layer to form N doped polysilicon layers in a direction away from the first surface of the substrate, wherein N>1, a power, a wavelength and a pulse irradiation number of a nth laser treatment are all smaller than a power, a wavelength and a pulse irradiation number of a n-1th laser treatment, and a grain size of the nth doped polysilicon layer is larger than a grain size of the n-1th doped polysilicon layer in the formed N doped polysilicon layers, wherein n≤N, and a first doped polysilicon layer is disposed toward the substrate. The embodiments of the present application are conducive to simplify the process of forming the solar cell.