TOPCon Solar Cell Passivation Stack for Lower Light Reflectivity
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Solution Overview
Problem
The light absorption efficiency of solar cells is limited by the parameters of the passivation structure, including the type and thickness of passivation layers, which hinders the further improvement of conversion efficiency.
Innovation Solution
A novel passivation structure comprising a first passivation layer of aluminum oxide, a second passivation layer of silicon nitride with a specific atomic ratio, and a third passivation layer of silicon oxynitride with a specific atomic ratio, optimized to enhance light absorption and reduce internal reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional passivation structures are used, then manufacturing process is simpler, but light absorption efficiency is limited and conversion efficiency cannot be further improved
Solution Approach 1:
The passivation structure is divided into three distinct layers: a first passivation layer (SiN x), a second passivation layer (SiO y), and a third passivation layer (SiO z). Each layer has specific thickness ranges and material compositions that work together to reduce light reflectivity and improve light absorption efficiency, while maintaining manufacturability through standardized deposition processes.
Solution Approach 2:
The patent employs a composite passivation structure combining three different dielectric materials (SiN x, SiO y, and SiO z) with varying refractive indices and optical properties. This composite approach enables superior light trapping and absorption compared to single-layer or two-layer structures, achieving over 30 mA increase in short-circuit current.
2Loss of energy
If passivation layer thickness is increased to improve light absorption, then light absorption efficiency improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise thickness parameters for each passivation layer: first layer 5-20 nm, second layer 20-50 nm, and third layer 50-100 nm. These parameter ranges are optimized to achieve the desired light absorption enhancement while remaining compatible with standard semiconductor fabrication capabilities, balancing performance improvement with manufacturing feasibility.
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 proposed passivation structure significantly reduces light reflectivity, particularly in the short-wave range, increasing the short-circuit current of TOPCON solar cells by over 30 mA and enabling the production of dark blue or black solar cells with improved photoelectric conversion efficiency.
Implementation Method 1
a first passivation layer, a second passivation layer and a third passivation layer sequentially formed on the front surface and in a direction away from the front surface... significantly reduces light reflectivity, particularly in the short-wave range
Implementation Method 2
The second passivation layer includes a first silicon nitride Si m N n material... The third passivation layer includes a silicon oxynitride SiO i N j material... optimized to enhance light absorption and reduce internal reflection
Data Source
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AI summary
A solar cell, a method for producing a solar cell and a solar cell module are provided. The solar cell includes: a substrate having a front surface and a rear surface opposite to the front surface; a first passivation layer, a second passivation layer and a third passivation layer sequentially formed on the front surface and in a direction away from the front surface; wherein the first passivation layer includes a dielectric material; the second passivation layer includes a first silicon nitride SimNn material, and a ratio of n/m is 0.5∼1;the third passivation layer includes a silicon oxynitride SiOiNj material, and a ratio of j/i is 0.1-0.6; and a tunneling oxide layer and a doped conductive layer sequentially formed on the rear surface and in a direction away from the rear surface, wherein the doped conductive layer and the substrate have a doping element of a same conductivity type.