Solar Cell Passivation Layer Dielectric Constant Optimization
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Solution Overview
Problem
Conventional silicon-based solar cells experience a decrease in reflective efficiency as the semiconductor material thickness decreases, leading to a high transmission rate of light and low light absorption, which results in a low photoelectric conversion efficiency.
Innovation Solution
A solar cell structure incorporating a semi-conductive substrate, a doping layer, an anti-reflection layer, an electrode, a passivation stacked layer, and a contact layer, where the passivation stacked layer consists of a first dielectric layer, a middle dielectric layer with a substantially lower dielectric constant, and a second dielectric layer, enhancing the reflective efficiency of light, particularly infrared light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the thickness of the semiconductor material is reduced, then the photoelectric conversion efficiency is improved, but the reflective efficiency decreases
Solution Approach 1:
The passivation layer is divided into multiple dielectric layers with different dielectric constants (first dielectric layer with higher dielectric constant, middle dielectric layer with lower dielectric constant, second dielectric layer with higher dielectric constant). This segmentation allows each layer to contribute differently to light reflection, creating a stacked structure that enhances overall reflective efficiency while maintaining thin semiconductor thickness.
Solution Approach 2:
The invention changes the dielectric constant parameter across different layers of the passivation structure. By arranging layers with alternating high and low dielectric constants, the optical impedance is optimized to maximize light reflection at the back surface, thereby improving reflective efficiency without increasing the semiconductor layer thickness.
2Productivity
If the thickness of the semiconductor material is reduced, then the photoelectric conversion efficiency is improved, but the light absorption rate decreases
Solution Approach 1:
The invention converts the harmful effect of high light transmission (which causes low light absorption) into a beneficial effect by using the transmitted light that reaches the back surface as the target for reflection. The multi-layer dielectric structure reflects this transmitted light back into the semiconductor, turning the previously wasted transmitted light into useful absorbed energy that contributes to photoelectric conversion.
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 enhanced reflective efficiency increases the performance of the solar cell by improving light absorption and photoelectric conversion, as demonstrated by the increased reflectivity of infrared light within the specified wavelength range.
Implementation Method 1
the reflective efficiency of light, particularly infrared light
Implementation Method 2
a dielectric constant of the middle dielectric layer is substantially lower than a dielectric constant of the first dielectric layer and a dielectric constant of the second dielectric layer
Implementation Method 3
The anti-reflection layer is disposed on the doping layer
Implementation Method 4
When sunlight illuminates a p-n structured semiconductor, energy provided by photons may excite electrons in the semiconductors to generate electron-hole pairs
Data Source
AI summary
A solar cell includes a semi-conductive substrate, a doping layer, an anti-reflection layer, an electrode, a passivation stacked layer and a contact layer. The semi-conductive substrate has a front and a back surface. The doping layer is disposed on the front surface. The anti-reflection layer is disposed on the doping layer. The electrode is disposed on the anti-reflection layer and electrically connected to the doping layer. The passivation stacked layer is disposed on the back surface and has a first dielectric layer, a second dielectric layer and a middle dielectric layer sandwiched between the first and the second dielectric layer. The dielectric constant of the middle dielectric layer is substantially lower than the dielectric constant of the first dielectric layer and the dielectric constant of the second dielectric layer. The contact layer covers the passivation stacked layer and electrically contacts with the back surface of the semi-conductive substrate.