Solar Cell Texture Structure Epitaxial Growth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solar cells face inefficiencies in power generation due to light reflection and absorption issues, which can be enhanced by optimizing the texture structure and amorphous silicon layer configurations on the substrate.
Innovation Solution
A solar cell design featuring a silicon substrate with a texture structure and amorphous silicon layers, where epitaxial growth is selectively accelerated on valley portions of the texture structure to reduce resistive loss and improve fill factor, while minimizing light absorption and maintaining open voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a texture structure is formed on the light-receiving surface to reduce light reflection, then light entry is improved, but light absorption may be reduced
Solution Approach 1:
The patent applies different treatments to different regions of the texture structure. Valley portions are selectively treated with amorphous silicon layers and epitaxial growth to have different optical and electrical properties compared to mountain portions, optimizing both light trapping and absorption locally
Solution Approach 2:
The patent converts the potentially harmful effect of light reflection (which reduces light entry) into a benefit by using the texture structure to trap light through multiple internal reflections, increasing the optical path length and enhancing absorption despite the initial reflection at the surface
2Productivity
If amorphous silicon layers are formed on the substrate, then power generation is improved, but manufacturing complexity increases
Solution Approach 1:
The patent performs preliminary actions by forming the texture structure first, then selectively depositing amorphous silicon layers in valley portions, and finally performing epitaxial growth. This staged approach simplifies manufacturing by preparing the substrate in advance with optimal features for subsequent processing steps
Solution Approach 2:
The texture structure creates a porous-like surface morphology with mountain and valley regions. This porous structure increases surface area for light interaction and provides sites for selective material deposition, improving power generation without requiring uniformly complex structures across the entire surface
3Loss of energy
If epitaxial growth is accelerated on valley portions, then resistive loss is reduced, but fill factor may be affected
Solution Approach 1:
The patent applies epitaxial growth selectively to valley portions rather than uniformly across the entire surface. This local quality approach reduces resistive loss in regions where it matters most (valley portions with higher current density) while maintaining overall device reliability by preserving the fill factor through controlled, localized growth
Solution Approach 2:
The patent changes the growth parameters (temperature, pressure, gas flow, time) to control the rate and extent of epitaxial growth. By optimizing these parameters, the patent achieves sufficient crystalline quality in valley portions to reduce resistive loss while limiting growth extent to maintain acceptable fill factor
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
The enhanced solar cell design increases power generation efficiency by reducing light reflection, improving fill factor, and minimizing the decrease in open voltage, thereby achieving better energy conversion rates.
Implementation Method 1
forming asperities called a texture structure on the light-receiving surface of the solar cell to reduce the reflection of light and at the same time to increase the amount of light entering the inside of the solar cell
Implementation Method 2
A solar cell includes a substrate with a texture structure formed thereon and amorphous silicon layers formed on the substrate
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Provided is a solar battery which, in a solar battery in which an amorphous silicon layer is formed upon the surface of a silicon substrate on which a texture structure is formed, is capable of reducing resistance loss caused by the amorphous silicon layer, and is capable of increasing power generation efficiency. The present invention is a solar battery provided with a silicon substrate (10) on which a texture structure, having ridges and troughs (13), is formed, and an amorphous silicon layer (20) provided upon the surface of the silicon substrate (1). In a cross-section passing through the ridges and the troughs (13), the texture structure has a pair of slanted portions (14) which are slanted so as to approach each other from a pair of mutually neighboring ridges toward a trough (13), and the trough (13) that is positionedbetween the slanted portions (14) has a rounded shape for which radius of curvature is less than or equal to 150 nm. The amorphous silicon layer (20) has, in the trough (13), an epitaxial growth area (23) that has grown from the trough (13) so as to become thicker than areas other than the trough (13).