Interdigitated Back Contact Solar Cell Eliminating Front Shading
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Solution Overview
Problem
Conventional solar cells face efficiency limitations due to front-side electrode shading, which restricts light absorption and requires complex fabrication steps, preventing effective use of back-side light absorption.
Innovation Solution
A solar cell design featuring interdigitated back contacts with tunneling oxide junctions and transparent conductive oxide materials, allowing for bi-facial light absorption and eliminating the need for front-side electrodes, thereby enhancing efficiency and simplifying fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If front-side electrodes are used to collect carriers, then carrier collection is achieved, but light absorption is reduced due to shading
Solution Approach 1:
The patent inverts the conventional solar cell architecture by moving both n-type and p-type electrodes to the back side of the cell. This inversion eliminates front-side shading while maintaining carrier collection functionality through interdigitated back contacts that separately collect electrons and holes
Solution Approach 2:
The patent transitions from a planar front-side electrode layout to a three-dimensional interdigitated back contact structure. The n-type and p-type electrodes are arranged in alternating fingers on the back side, creating a vertical dimension for carrier collection that eliminates the horizontal shading problem
2Illumination intensity
If both p-type and n-type electrodes are placed on the back side, then front-side shading is eliminated, but fabrication complexity increases
Solution Approach 1:
The patent segments the back contact into distinct n-type and p-type regions with interleaved finger structures. This segmentation allows separate optimization of each electrode type while maintaining a unified back-contact architecture that simplifies the overall fabrication process compared to conventional multi-layer front-side structures
3Productivity
If conventional front-side electrodes are used, then carrier collection is efficient, but module packing factor is reduced
Solution Approach 1:
By inverting the electrode location to the back side, the patent eliminates the need for front-side grid patterns that consume valuable active area. This allows for larger active areas and higher module packing factors while maintaining efficient carrier collection through the interdigitated back contact structure
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 increases short-circuit current and open-circuit voltage while enabling bi-facial operation, allowing the solar cell to absorb light from both sides, thus improving overall efficiency and module packing factor.
Implementation Method 1
tunneling oxide junctions
Implementation Method 2
Solar cell is a photovoltaic structure capable of converting light into electricity
Data Source
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AI summary
A solar cell with an interdigitated back contact is provided. The solar cell can include a crystalline silicon base layer and an electron collector region on a back side of the base layer. The electron collector region can include a first conductive oxide material electrically coupled to the base layer. The solar cell can also include a hole collector region on the back side of the base layer. The hole collector region can include a second conductive oxide material electrically coupled to the base layer. The electron collector region and hole collector region can form an interdigitated pattern. Furthermore, the first conductive oxide material and second conductive oxide material have different work functions.