Solar Cell Emitter Architecture With Passivation-Contact Layer
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Solution Overview
Problem
Existing solar cell fabrication methods face challenges in achieving efficient and cost-effective production, particularly in providing a hydrogen source for N-type polycrystalline silicon emitters and ensuring direct metal contact without additional contact processes.
Innovation Solution
Incorporating an N-type amorphous silicon layer for passivation and direct metal contact, which provides hydrogen to the underlying N-type emitter region and simplifies the contact process, eliminating the need for additional steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional fabrication methods are used for N-type emitters, then the emitter can be formed, but additional contact processes are required and hydrogen source provision is complex
Solution Approach 1:
The amorphous silicon layer is designed to perform multiple functions simultaneously: it serves as a hydrogen source for the N-type emitter, provides passivation, and enables direct metal contact. This multi-functionality eliminates the need for separate contact formation processes, directly resolving the contradiction between manufacturing simplicity and process complexity.
Solution Approach 2:
The patent combines the hydrogen source function, passivation function, and contact formation function into a single amorphous silicon layer. By merging these previously separate functions into one integrated layer, the fabrication process is simplified while maintaining all necessary functions, thus resolving the contradiction between ease of manufacture and device complexity.
2Loss of energy
If saturation current density is reduced to improve efficiency, then power losses decrease, but additional passivation and contact layers are required
Solution Approach 1:
The amorphous silicon layer is engineered to simultaneously provide passivation (reducing saturation current density and power losses) and enable direct metal contact. This multi-functionality achieves energy efficiency improvement without adding device complexity, as one layer performs both the passivation and contact formation functions that would traditionally require separate components.
Solution Approach 2:
The amorphous silicon layer is applied specifically at the contact regions where it provides localized passivation and hydrogenation. This localized application reduces saturation current density at critical interfaces without requiring global structural changes, thus improving energy efficiency while minimizing increases in device 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
This approach enhances solar cell efficiency by reducing saturation current density and simplifying the fabrication process, leading to lower power losses and improved manufacturing efficiency.
Implementation Method 1
provides hydrogen to the underlying N-type emitter region
Implementation Method 2
direct conversion of solar radiation into electrical energy
Data Source
AI summary
Methods of fabricating solar cell emitter regions with differentiated P-type and N-type architectures and incorporating a multi-purpose passivation and contact layer, and resulting solar cells, are described. In an example, a solar cell includes a substrate having a light-receiving surface and a back surface. A P-type emitter region is disposed on the back surface of the substrate. An N-type emitter region is disposed in a trench formed in the back surface of the substrate. An N-type passivation layer is disposed on the N-type emitter region. A first conductive contact structure is electrically connected to the P-type emitter region. A second conductive contact structure is electrically connected to the N-type emitter region and is in direct contact with the N-type passivation layer.