Offset-Contact Solar Cell Architecture to Prevent Laser Damage
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Solution Overview
Problem
Existing solar cell structures face challenges in increasing efficiency and reducing manufacturing costs, particularly due to issues such as laser damage, alignment tolerance, and aluminum spiking during the fabrication of contacts with emitter regions.
Innovation Solution
Implementing an offset contact structure that decouples semiconductor layer contacts from the substrate, using dielectric layers to prevent laser damage and eliminate aluminum spiking, allowing for varied emitter shapes and reduced butting junction areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contacts are formed directly over emitter regions, then electrical connection is achieved, but laser damage and aluminum spiking occur during fabrication
Solution Approach 1:
The contact structure is moved from a vertical alignment (directly over the emitter) to a lateral offset position. The conductive contact is formed in a first opening at a first location outside the perimeter of the emitter region, and connected to the emitter through a semiconductor layer that extends laterally. This dimensional shift eliminates laser damage and aluminum spiking while maintaining electrical connection.
Solution Approach 2:
A semiconductor layer acts as an intermediary between the conductive contact and the emitter region. This intermediate layer provides a controlled pathway for electrical connection while preventing direct contact between the conductive material and the emitter, thereby eliminating harmful effects like aluminum spiking and laser damage during fabrication.
2Object-affected harmful factors
If contacts are offset from emitter regions, then laser damage and aluminum spiking are eliminated, but alignment tolerance and manufacturing precision are challenged
Solution Approach 1:
The contact structure is segmented into multiple components: a conductive contact in a first opening at a first location, a semiconductor layer extending from the contact to the emitter region, and the emitter region itself. This segmentation allows each component to be formed with independent tolerances, reducing the cumulative alignment requirements and simplifying manufacturing precision requirements.
3Ease of manufacture
If traditional contact structures are used, then fabrication is simpler, but efficiency is reduced due to laser damage and alignment issues
Solution Approach 1:
The invention changes the spatial parameters of the contact structure by offsetting it from the emitter region. This parameter change (positioning) eliminates the need for high-precision alignment while maintaining electrical connection, thereby improving efficiency without significantly complicating the fabrication process.
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
Enhances solar cell efficiency by minimizing laser damage and alignment issues, thereby improving manufacturing precision and reducing costs through the use of offset contacts.
Implementation Method 1
using dielectric layers to prevent laser damage
Implementation Method 2
Solar radiation impinging on the surface of, and entering into, the substrate of a solar cell creates electron and hole pairs in the bulk of the substrate
Data Source
AI summary
A solar cell, and methods of fabricating said solar cell, are disclosed. The solar cell can include a first emitter region over a substrate, the first emitter region having a perimeter around a portion of the substrate. A first conductive contact is electrically coupled to the first emitter region at a location outside of the perimeter of the first emitter region.