Screen Printed Doping Regions for Solar Cells
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Solution Overview
Problem
The formation of patterned doping regions in solar cells is complex and costly due to the need for high-temperature and photolithography processes, which increases the manufacturing cost and reduces efficiency.
Innovation Solution
A method using screen printing and thermal diffusion with phosphoric acid or boric acid to form p-type and n-type patterned doping regions, eliminating the need for photolithography and reducing process complexity, with a covering layer of Al2O3 to control diffusion and enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography and high-temperature processes are used to form patterned doping regions, then manufacturing precision and doping accuracy are improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and removes the photolithography process from the doping formation sequence, replacing it with a direct screen printing method that deposits doping materials through printed resist patterns. This eliminates the need for separate photolithography steps while maintaining the ability to form precise patterned doping regions.
Solution Approach 2:
The patent combines the resist deposition and doping material deposition into a single screen printing step. The resist and doping materials are co-printed through the same screen in one operation, merging what were previously separate processes (resist coating, photolithography, and doping) into a unified step that reduces overall process complexity.
2Manufacturing precision
If photolithography and high-temperature processes are used to form patterned doping regions, then doping accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes the expensive photolithography process from the manufacturing sequence and replaces it with screen printing, which uses simpler, more cost-effective equipment and materials. This extraction of the photolithography step directly reduces manufacturing costs while preserving doping accuracy through the printed resist patterns.
Solution Approach 2:
The patent employs disposable printed resist patterns that are created directly on the substrate through screen printing. These resist patterns serve their purpose during the doping process and are then removed, eliminating the need for expensive, reusable photolithography masks and reducing overall manufacturing costs.
3Reliability
If multiple high-temperature processes are used to form patterned doping regions, then photoelectric conversion efficiency is improved, but productivity decreases
Solution Approach 1:
The patent merges multiple separate high-temperature processes into a single unified screen printing and firing operation. The resist and doping materials are deposited and activated in one thermal processing step, eliminating the need for separate photolithography and doping furnaces, thereby improving manufacturing efficiency without compromising the quality of the doping regions.
Solution Approach 2:
The patent performs preliminary preparation of the resist and doping material mixture before the actual doping process. The screen print paste is pre-formulated with both resist and doping materials in the correct proportions and configurations, allowing the entire patterned doping structure to be created in a single printing and firing cycle, thus improving productivity.
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 simplifies the formation of patterned doping regions, reducing manufacturing costs and improving the accuracy and efficiency of solar cell production while maintaining high photoelectric conversion efficiency.
Implementation Method 1
a method using screen printing and thermal diffusion with phosphoric acid or boric acid to form p-type and n-type patterned doping regions
Implementation Method 2
with a covering layer of Al2O3 to control diffusion and enhance accuracy
Data Source
Figure 1A~1D
Figure 1E~1G
Figure 2A~2D
AI summary
A method for forming doping regions is disclosed, including providing a substrate, forming a first-type doping material on the substrate and forming a second-type doping material on the substrate, wherein the first-type doping material is separated from the second-type doping material by a gap; forming a covering layer to cover the substrate, the first-type doping material and the second-type doping material; and performing a thermal diffusion process to diffuse the first-type doping material and the second-type doping material into the substrate.