Solar Cell Transparent Conductive Layer Texturing
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Solution Overview
Problem
Existing solar cell technologies face limitations in enhancing incident light efficiency, particularly in the design of thin-film solar cells, where the texturing of transparent conductive layers often results in steep patterns that increase reflection and reduce transmittance, leading to suboptimal electricity generation.
Innovation Solution
A method of fabricating solar cells involving the use of an etchant solution with an acid of molecular weight 58-300, such as acetic acid, to texture the upper surface of the first transparent conductive layer, forming a rounded uneven pattern that minimizes side etching and enhances transmittance, thereby improving light entry into the photoelectric conversion layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a textured structure with steep pattern is formed on the transparent conductive layer, then light scattering effect is enhanced, but reflection increases and transmittance decreases
Solution Approach 1:
The patent applies curvature principle by forming a rounded uneven pattern instead of steep patterns on the transparent conductive layer. The rounding of the texture pattern reduces light reflection while maintaining scattering effects, thereby improving transmittance and reducing energy loss through reflection.
Solution Approach 2:
The patent changes the geometric parameters of the textured pattern by controlling etching conditions (etchant solution composition, temperature, time) to create a rounded profile with optimized pitch and depth. This parameter optimization balances light scattering enhancement with reflection minimization, resolving the contradiction between illumination intensity improvement and energy loss reduction.
2Illumination intensity
If texturing is performed to improve light entry, then incident light efficiency is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent employs self-service principle by utilizing the natural etching characteristics of the transparent conductive layer material (such as ZnO) with specific etchant solutions to automatically form the desired rounded uneven pattern. The material's inherent properties and the etching process work together to create the optimal texture without requiring additional complex processing steps or equipment.
Solution Approach 2:
The patent simplifies manufacturing by optimizing etching parameters (etchant composition, temperature, time) to achieve the desired rounded texture pattern in a single step. By carefully controlling these parameters, the process achieves both the required light management performance and manufacturing simplicity, avoiding the need for multiple complex processing steps.
3Stability of the object's composition
If high-temperature processing is used to form transparent conductive layer, then crystallization is improved, but defects and non-uniformity increase
Solution Approach 1:
The patent resolves this contradiction by changing the temperature parameter to low-temperature processing (below conventional high-temperature ranges). This low-temperature approach, combined with optimized etching parameters and material selection, achieves sufficient crystallization quality while preventing the formation of defects and non-uniformity that occur at high temperatures, thereby improving manufacturing precision.
Solution Approach 2:
The patent may utilize composite material approaches by combining specific transparent conductive layer materials with particular etchant solutions and doping elements. This composite strategy enables low-temperature processing while maintaining good crystallization quality, as the material composition is optimized to work effectively at lower temperatures without forming defects.
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 results in improved incident light efficiency and electricity generation by reducing reflection, allowing more solar light to enter the solar cell and reducing the resistance of the transparent conductive layer, while being compatible with low-temperature processing to prevent defects and non-uniform crystallization.
Implementation Method 1
texturing an upper surface of the first transparent conductive layer using an etchant solution configured to contain an acid with a molecular weight of about 58 ̃300
Implementation Method 2
The solar cell fabricating method can form the first transparent conductive layer having a rounded uneven pattern. In other words, the solar cell fabricating method allows the first transparent conductive layer to an uneven pattern with a great pitch. Accordingly, it can be provided a solar cell which has an enhanced transmittance in a boundary surface of the first transparent conductive layer.
Implementation Method 3
the solar cell generates electron/hole pairs within its semiconductor by external light
Implementation Method 4
the electrons move to an n-type semiconductor and the holes move to a p-type semiconductor, by an electric field generated at a p-n junction
Data Source
AI summary
A method of fabricating a solar cell is disclosed. The solar cell fabricating method includes forming a first transparent conductive layer on a transparent substrate, texturing an upper surface of the first transparent conductive layer using an etchant solution configured to contain an acid with a molecular weight of about 58˜300, forming a photoelectric conversion layer on the first transparent conductive layer, forming a second transparent conductive layer on the photoelectric conversion layer, and forming a rear electrode on the second transparent conductive layer.