Solar Cell Strip Junction Exclusion to Cut Separation Losses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solar modules have limited power conversion efficiency due to defects arising from the separation process of photovoltaic cell strips, which lead to electron-hole recombination and reduced power output.
Innovation Solution
The solution involves excluding the p-n junction from regions where strip separation occurs by physical removal of material, changing the doping level, or not forming the junction in these regions, thereby imposing distance between the junction and potential defects and reducing electron-hole recombination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If photovoltaic cell strips are separated using conventional methods, then manufacturing productivity is improved, but defects arise at separation regions causing electron-hole recombination and reducing power conversion efficiency
Solution Approach 1:
The patent extracts the p-n junction from the inter-strip regions where separation occurs. By removing the junction from these problematic areas through physical material removal, doping level modification, or masking during dopant introduction, the source of electron-hole recombination is eliminated while maintaining the separation process's productivity benefits
Solution Approach 2:
The patent applies preliminary action by modifying the inter-strip regions before the separation process. Through counter-doping, deactivation, or masking during original dopant introduction, the junction is prevented from forming in separation zones, thereby preventing future recombination losses while enabling clean strip separation
2Loss of energy
If material is physically removed from inter-strip regions to exclude the junction, then power conversion efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent integrates junction exclusion into the existing doping process through masking during original dopant introduction. This approach incorporates the junction exclusion function into an already-established manufacturing step, avoiding the need for separate material removal operations and thereby limiting the increase in manufacturing complexity
Solution Approach 2:
The patent modifies doping parameters in inter-strip regions through counter-doping or deactivation processes. By changing the doping level or type in these regions, the junction is excluded without requiring physical material removal, thus improving power conversion efficiency while maintaining relatively simple manufacturing processes
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 enhances the power conversion efficiency of shingled modules by minimizing losses associated with defects, resulting in up to 20% more power output compared to conventional modules without incremental costs.
Implementation Method 1
Photovoltaic devices are becoming an increasingly important element of global energy production
Implementation Method 2
changing an effective doping level (e.g., counter-doping, deactivation) at inter-strip regions
Data Source
AI summary
Separation of individual strips from a solar cell workpiece, is accomplished by excluding a junction (e.g., a homojunction such as a p-n junction, or a heterojunction such as a p-i-n junction) from regions at which separation is expected to occur. According to some embodiments, the junction is excluded by physical removal of material from inter-strip regions of the workpiece. According to other embodiments, exclusion of the junction is achieved by changing an effective doping level (e.g., counter-doping, deactivation) at inter-strip regions. For still other embodiments, the junction is never formed at inter-strip regions in the first place (e.g., using masking during original dopant introduction). By imposing distance between the junction and defects arising from separation processes (e.g., backside crack propagation), losses attributable to electron-hole recombination at such defects are reduced, and collection efficiency of shingled modules is enhanced.