Backside-Junction Solar Cell With Front Contact and IR Reflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solar cell manufacturing processes struggle to produce efficient and cost-effective front contact solar cells that balance solar radiation collection with aesthetic considerations, particularly for residential applications where metal contacts on the front side are undesirable.
Innovation Solution
A bipolar solar cell design featuring a backside junction with an N-type silicon substrate and P-type polysilicon emitter, combined with a negative polarity metal contact on the front side and a positive polarity metal contact on the backside that forms an infrared reflecting layer, along with an antireflection layer on the textured front surface to enhance solar radiation collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If metal contacts are placed on the front side of the solar cell to enable electrical connection, then electrical functionality is achieved, but aesthetic appearance deteriorates due to visible metal contacts
Solution Approach 1:
The patent moves metal contacts from the front side (2D surface) to the backside (another dimension/side) of the solar cell, allowing electrical connections to be made without compromising the front surface aesthetics. This dimensional relocation resolves the contradiction by separating the functional requirement (metal contacts) from the aesthetic requirement (clean front surface).
Solution Approach 2:
The patent inverts the conventional front-contact configuration by implementing a backside-contact design where metal contacts are placed on the rear surface of the solar cell. This inversion allows the front surface to remain free of metal contacts, maintaining aesthetic appearance while still providing necessary electrical connectivity through the backside contacts.
2Shape
If metal contacts are removed from the front side to improve aesthetics, then aesthetic appearance is improved, but solar radiation collection efficiency deteriorates due to reduced active area
Solution Approach 1:
The patent relocates metal contacts to the backside of the solar cell, effectively utilizing the rear surface area for electrical connections. This allows the entire front surface to be dedicated to solar radiation collection, maximizing the active area and efficiency while maintaining aesthetic appearance.
Solution Approach 2:
The patent segments the solar cell into distinct functional zones: the front surface is dedicated solely to light absorption and photon-to-electron conversion, while the backside handles electrical connections and contact functions. This segmentation allows each surface to optimize its specific function without compromising the other.
3Ease of operation
If conventional front contact design is used to ensure efficient electrical connection, then electrical functionality is improved, but manufacturing complexity increases due to additional processing steps
Solution Approach 1:
The patent extracts the metal contact function from the front surface processing sequence and relocates it to the backside. This extraction simplifies the front surface manufacturing steps by eliminating the need for front-contact patterning, metallization, and alignment processes, thereby reducing overall manufacturing complexity.
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 enables efficient solar radiation collection while maintaining a clean front surface aesthetic, improving power generation efficiency and reducing manufacturing costs by optimizing metal contact placement and using antireflection layers.
Implementation Method 1
An antireflection layer may be formed on a textured front surface of the silicon substrate
Implementation Method 2
textured front surface of the silicon substrate
Implementation Method 3
The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection
Implementation Method 4
Solar radiation impinging on the solar cell creates electrons and holes that migrate to the diffusion regions, thereby creating voltage differentials between the diffusion regions
Data Source
AI summary
A bipolar solar cell includes a backside junction formed by an N-type silicon substrate and a P-type polysilicon emitter formed on the backside of the solar cell. An antireflection layer may be formed on a textured front surface of the silicon substrate. A negative polarity metal contact on the front side of the solar cell makes an electrical connection to the substrate, while a positive polarity metal contact on the backside of the solar cell makes an electrical connection to the polysilicon emitter. An external electrical circuit may be connected to the negative and positive metal contacts to be powered by the solar cell. The positive polarity metal contact may form an infrared reflecting layer with an underlying dielectric layer for increased solar radiation collection.