Solar Cell Textured Surface Cleaning via Segmented Chemical Etching
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Solution Overview
Problem
Existing solar cell manufacturing methods fail to efficiently remove damaged surface portions and impurities from textured surfaces, leading to reduced efficiency and stability of solar cells.
Innovation Solution
A method involving a dry etching process to form textured surfaces, followed by a basic chemical cleansing process to remove damaged areas and impurities, and subsequent acid chemical cleansing to further purify the surfaces, along with the formation of emitter regions using ion implantation, and the application of multi-layered dielectric and electrode structures to enhance light absorption and passivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a dry etching process is performed to form a textured surface, then light absorption is enhanced, but damaged surface portions and impurities are generated on the minute protrusions
Solution Approach 1:
The patent divides the surface treatment into multiple sequential cleansing steps: first cleansing process using a basic chemical solution to remove damaged portions, second cleansing process using an acid chemical solution to remove impurities, and optional third cleansing process with diluted acid chemical. This segmented approach systematically addresses different types of contamination separately, effectively resolving the contradiction between enhancing light absorption through texturing and removing the resulting damaged surfaces and impurities.
2Productivity
If multiple cleansing processes are performed to remove impurities, then solar cell efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs parameter changes by using different chemical solutions with specific compositions and concentrations for each cleansing step. The basic chemical solution (e.g., ammonium hydroxide, hydrogen peroxide, water in 1:1:5 ratio) targets damaged surface portions, while the acid chemical solution (e.g., hydrofluoric acid, water in 1:10 ratio) targets impurities. By optimizing chemical parameters for each step, the patent achieves effective contamination removal while maintaining manageable process complexity through systematic parameter control.
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 improves the current characteristics of solar cells by efficiently removing impurities and damaged surfaces, enhancing light absorption, and reducing reflection, thereby increasing the overall efficiency and stability of the solar cells.
Implementation Method 1
performing a first cleansing process for removing damaged portions of surfaces of the minute protrusions using a basic chemical
Implementation Method 2
removing impurities adsorbed on the surfaces of the minute protrusions
Implementation Method 3
performing a second cleansing process for removing impurities remaining or again adsorbed on the surfaces of the minute protrusions using an acid chemical
Implementation Method 4
removing impurities adsorbed on the surfaces of the minute protrusions
Implementation Method 5
injecting impurities of a first conductive type into the first surface of the semiconductor substrate using an ion implantation method
Implementation Method 6
injecting impurities of a first conductive type into the first surface of the semiconductor substrate using an ion implantation method or a thermal diffusion method
Implementation Method 7
forming a first dielectric layer on the second surface of the semiconductor substrate, simultaneously forming a second dielectric layer on the emitter region and on the first dielectric layer
Data Source
AI summary
A method for manufacturing a solar cell includes performing a dry etching process to form a textured surface including a plurality of minute protrusions on a first surface of a semiconductor substrate, performing a first cleansing process for removing damaged portions of surfaces of the minute protrusions using a basic chemical and removing impurities adsorbed on the surfaces of the minute protrusions, performing a second cleansing process for removing impurities remaining or again adsorbed on the surfaces of the minute protrusions using an acid chemical after performing the first cleansing process, and forming an emitter region at the first surface of the semiconductor substrate.