Photovoltaic Cell Tunnel Oxide Doping for Lower Interface Recombination
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Solution Overview
Problem
Conventional photovoltaic cells have low reliability due to interface recombination between metal electrodes and substrates, caused by the metal electrode penetrating the tunnel oxide layer, which reduces open circuit voltage and efficiency.
Innovation Solution
A photovoltaic cell design incorporating a tunnel oxide layer doped with nitrogen and phosphorus, combined with a doping surface field of the same conductivity type as the substrate, to enhance passivation effects and reduce series resistance, even when the metal electrode penetrates the tunnel oxide layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional tunnel oxide layer and doping conductive layer are disposed on the substrate surface, then good chemical passivation and field passivation effects are achieved, but interface recombination occurs when metal electrodes penetrate the tunnel oxide layer, reducing reliability
Solution Approach 1:
The patent changes the chemical composition parameters of the tunnel oxide layer by doping it with nitrogen and phosphorus elements. This modifies the oxide layer's properties to simultaneously achieve good passivation effect and allow metal electrode penetration without severe interface recombination, resolving the contradiction between maintaining passivation quality and enabling reliable electrode contact.
Solution Approach 2:
The patent creates a composite tunnel oxide layer by combining silicon oxide with nitrogen and phosphorus dopants. This composite structure integrates the insulating and passivating properties of silicon oxide with the beneficial electrical properties introduced by nitrogen and phosphorus, enabling both good passivation and reduced interface recombination when metal electrodes penetrate the layer.
2Reliability
If the tunnel oxide layer is made thicker to improve passivation, then chemical passivation effect is enhanced, but series resistance increases and carrier transmission efficiency decreases
Solution Approach 1:
The patent changes the compositional parameters of the tunnel oxide layer by introducing nitrogen and phosphorus dopants. These compositional changes enable the oxide layer to maintain good passivation properties at reduced thickness, thereby lowering series resistance and improving carrier transmission efficiency while preserving adequate passivation effect.
Solution Approach 2:
The patent creates local quality variations within the tunnel oxide layer through non-uniform doping with nitrogen and phosphorus. The dopant distribution is optimized to provide enhanced passivation where needed while maintaining good carrier transmission properties in other regions, resolving the contradiction between passivation quality and series resistance.
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 solution improves the reliability of photovoltaic cells by maintaining good passivation effects and carrier transmission efficiency, even if the metal electrode penetrates the tunnel oxide layer, thereby enhancing open circuit voltage and overall performance.
Implementation Method 1
The tunnel oxide layer has good chemical passivation effect
Implementation Method 2
the doping conductive layer has good field passivation effect
Implementation Method 3
The photovoltaic cell has good photoelectric conversion capability
Data Source
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AI summary
Embodiments of the present disclosure relate in general to photovoltaic cell technologies, and more specifically to a photovoltaic cell, a method for manufacturing the photovoltaic cell and a photovoltaic module. The photovoltaic cell includes: a substrate; a tunnel oxide layer and a doping conductive layer sequentially disposed on a first surface of the substrate in a direction away from the substrate, wherein the tunnel oxide layer includes nitrogen and phosphorus; a doping surface field disposed in the substrate, wherein the doping surface field is in contact with a side surface of the tunnel oxide layer facing the substrate, the doping surface field has a doping element of a same conductivity type as the substrate, and a doping concentration on a side of the doping surface field facing the tunnel oxide layer is greater than a doping concentration on a side of the doping surface field away from the tunnel oxide layer; and a metal electrode electrically connected to the doping conductive layer.