Passivated Contact Solar Cell Layout for Lower Recombination Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solar cells face efficiency limitations due to contact recombination in metal-silicon contact areas and Auger and deep-level recombination in silicon substrates, which are not adequately addressed by existing technologies like TOPCon cells that suffer from parasitic absorption by doped polysilicon layers.
Innovation Solution
A solar cell design with alternately arranged passivation and passivated contact regions on a semiconductor substrate, where passivating contact structures are spaced to reduce long-wavelength light absorption, enhancing electric currents and efficiency while maintaining effective passivation without complex preparation processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal contact structures are directly formed on the semiconductor substrate, then good electrical contact is achieved, but metal atoms diffuse into the substrate causing performance degradation
Solution Approach 1:
An intrinsic or weakly doped semiconductor layer is introduced between the metal contact structure and the heavily doped semiconductor substrate. This intermediate layer acts as a barrier that prevents metal atoms from diffusing into the substrate while maintaining electrical conductivity, thereby eliminating the harmful effect of metal atom diffusion without compromising electrical contact stability.
2Object-generated harmful factors
If a thick intrinsic semiconductor layer is added to prevent metal atom diffusion, then metal diffusion is blocked, but the fill factor and light absorption are reduced
Solution Approach 1:
Instead of uniformly thick intrinsic layer across the entire contact region, the patent applies the intrinsic or weakly doped semiconductor layer only in specific localized areas where metal contact structures are formed. This localized approach prevents metal atom diffusion at the contact points while maintaining good electrical contact and preserving the fill factor and light absorption properties of the overall solar cell structure.
3Reliability
If the semiconductor layer is heavily doped to improve conductivity, then electrical contact is improved, but metal atom diffusion into the substrate increases
Solution Approach 1:
The patent creates a doping gradient where the semiconductor layer has different doping concentrations in different regions. The region beneath the metal contact structure is lightly doped or intrinsic to prevent metal atom diffusion, while other regions maintain higher doping concentrations for good electrical conductivity. This spatial variation in doping quality allows simultaneous achievement of low diffusion and high conductivity.
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 design increases short-circuit currents and overall efficiency by reducing long-wavelength light absorption and maintaining effective passivation, making it suitable for mass production.
Implementation Method 1
a first semiconductor layer (110), having a first type of conductivity type, is provided. a second semiconductor layer (110), having a second type of conductivity type different from the first type of conductivity type, is provided on the first semiconductor layer (110)
Implementation Method 2
Each passivating contact structure (12) includes an electrically conductive passivation layer (122)
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
The present disclosure relates to a solar cell, a preparation method thereof, and a photovoltaic module. The solar cell includes a semiconductor substrate, passivating contact structures, a dielectric layer, and first electrodes. The semiconductor substrate includes a first surface and a second surface opposite to each other. The semiconductor substrate includes passivation regions and passivated contact regions, which are alternately arranged along a first direction. The first direction is perpendicular to a thickness direction of the semiconductor substrate. The passivating contact structures are disposed on the second surface and correspondingly disposed on the passivated contact regions. Each passivating contact structure includes an electrically conductive passivation layer. The dielectric layer at least covers the second surface in the passivation regions. The first electrodes are disposed on the passivating contact structures at a side away from the semiconductor substrate. Each passivating contact structure is provided with at least one first electrode.