Method for manufacturing solar cell having selective emitter and solar cell manufactured thereby
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Solution Overview
Problem
Solar cells with selective emitters face inefficiencies due to misalignment of electrode patterns, leading to increased parallel resistance and reduced fill factor, necessitating an accurate alignment method for enhanced matching between electrode patterns and prepared electrode lines.
Innovation Solution
A method involving primary and secondary doping to form alignment marks and electrode patterns, where primary doping creates a distinct alignment mark and electrode pattern portion, and secondary doping differentiates these as first and second emitter portions, allowing for aligned printing of solar cell electrodes using the alignment marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If aligned printing is performed without alignment marks, then manufacturing process is simpler, but electrode pattern alignment precision deteriorates
Solution Approach 1:
Alignment marks are formed during the primary doping process before the printing step, preparing reference features in advance that enable precise alignment during subsequent electrode pattern formation without adding complex alignment equipment
Solution Approach 2:
Alignment marks serve as intermediary reference features that mediate between the doping process and the printing process, enabling accurate alignment by providing visual or optical references for positioning electrode patterns relative to emitter regions
2Reliability
If dopant concentration in emitter is increased, then contact resistance decreases, but short circuit current density and open circuit voltage decrease
Solution Approach 1:
The emitter is divided into regions with different dopant concentrations: heavily doped regions under electrode patterns for low contact resistance, and lightly doped regions in other areas for high short circuit current density and open circuit voltage, optimizing both parameters simultaneously
Solution Approach 2:
The dopant concentration parameter is varied spatially across the emitter, transitioning from uniform doping to selective doping with different concentrations in different regions, enabling simultaneous optimization of electrical contact and photovoltaic performance
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 method improves the matching between electrode patterns and electrode lines, resulting in enhanced solar cell conversion efficiency and fill factor by ensuring precise alignment and dopant concentration differences.
Implementation Method 1
performing primary doping in which a dopant is doped locally on one surface of a substrate to form an electrode pattern portion and an alignment mark
Implementation Method 2
performing secondary doping in which a dopant is doped over the primarily doped surface of the substrate
Implementation Method 3
When light enters such a solar cell, electrons within the semiconductor become free electrons (hereinafter, referred to as 'electrons') through a photoelectric effect
Data Source
AI summary
The present invention relates to a method for manufacturing a solar cell comprising a selective emitter, the method comprising the steps of: forming an electrode pattern and an alignment mark by performing a first impurity doping locally on one surface of a substrate; and performing a second impurity doping on the entire surface of the first doped substrate, wherein, as a result of the first and second doping, the alignment mark is formed on a first emitter or a second emitter, and the electrode pattern is formed on the second emitter. When manufacturing the selective emitter, the alignment mark is formed by doping processes. The use of the alignment mark may increase the matching of the electrode pattern formed in the selective emitter and the resulting electrode line. Further, a solar cell having the selective emitter has excellent conversion efficiency and a high fill factor value.