Rear-Passivated Solar Cell Layout for Front Shading and Recombination
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Solution Overview
Problem
Existing solar cells face challenges in maximizing photoelectric conversion efficiency due to light blocking by front surface electrodes and carrier recombination on the rear surface, which limits open-circuit voltage and overall efficiency.
Innovation Solution
A solar cell design featuring a substrate with a tunneling layer and a doped conductive layer on the rear surface, comprising first and second regions with different doping types, reduces carrier recombination and allows electrodes to be placed on the rear surface, enhancing passivation and light absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrodes are formed on the front surface of the solar cell, then electrical connection is achieved, but light blocking occurs which reduces light absorption
Solution Approach 1:
The patent inverts the conventional electrode placement by forming all electrodes on the rear surface of the solar cell instead of the front surface. This inversion eliminates light blocking on the front surface, allowing maximum light absorption while maintaining electrical connection through the rear contact structure with doped conductive layers and metal electrodes.
2Reliability
If a tunneling layer with high dopant concentration is used, then passivation effect is improved, but carrier recombination increases
Solution Approach 1:
The patent applies local quality by creating different doping concentrations in different regions of the tunneling layer. The first regions have a first dopant concentration optimized for passivation, while the second regions have a second dopant concentration optimized for carrier collection. This spatial variation in doping quality allows simultaneous optimization of passivation effect and reduction of carrier recombination.
Solution Approach 2:
The patent changes the doping concentration parameter within the tunneling layer by forming regions with different dopant concentrations. The first regions have doping concentration in the range of 1×10^19 to 1×10^21 atoms/cm³, while the second regions have doping concentration in the range of 1×10^20 to 1×10^22 atoms/cm³. This parameter variation enables optimization of both passivation and carrier collection.
3Ease of manufacture
If uniform doping is applied throughout the tunneling layer, then manufacturing is simplified, but photoelectric conversion efficiency is reduced
Solution Approach 1:
The patent implements local quality by forming first regions and second regions with different doping concentrations in the tunneling layer. The first regions have lower dopant concentration for passivation, while the second regions have higher dopant concentration for carrier collection. This non-uniform doping structure optimizes photoelectric conversion efficiency by addressing different functional requirements in different areas.
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 significantly improves open-circuit voltage and photoelectric conversion efficiency by reducing carrier recombination and light blocking, while maintaining high light absorption.
Implementation Method 1
a passivation contact structure formed by a tunneling layer and a doped conductive layer disposed on a rear surface of a substrate can significantly reduce recombination of carriers occurred on the rear surface of the substrate
Implementation Method 2
tunneling layer formed on the rear surface of the substrate
Implementation Method 3
Because solar cells have excellent photoelectric conversion efficiency, the solar cells are becoming the focus of development for clean energy utilization
Data Source
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AI summary
Embodiments of the present disclosure relate to a solar cell and a photovoltaic module. The solar cell includes: a substrate having a front surface and a rear surface opposite to each other, a tunneling layer formed on the rear surface of the substrate, and a doped conductive layer formed on the tunneling layer. The tunneling layer includes first regions and second regions, the first regions interleave with the second regions in a first direction, and the first regions include first dopant atoms. The doped conductive layer includes first doped regions and second doped regions, each first doped region is formed on a respective first region, and each second doped region is formed on a respective second region. The first doped regions have a doping type different from a doping type of the second doped regions, the first doped regions include the first dopant atoms, and an atomic percentage of the first dopant atoms in the first doped regions is lower than an atomic percentage of the first dopant atoms in the first regions. The present disclosure is at least conducive to improving the photoelectric conversion efficiency of the solar cell.