IBC Solar Cell Leakage Structure for Hot Spot Mitigation
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Solution Overview
Problem
IBC photovoltaic modules are prone to hot spot effects due to shading, leading to decreased output power, and existing solutions fail to effectively mitigate this issue.
Innovation Solution
An IBC solar cell design featuring a leakage conductive structure with overlapping conductive blocks and a tunneling layer between them, allowing carrier passage under reverse bias to form a leakage current path, reducing hot spot effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If IBC photovoltaic modules are used for their high power density and aesthetic appearance, then power output and visual quality are improved, but they become susceptible to hot spot effects from shading
Solution Approach 1:
The patent introduces a leakage conductive structure as an intermediary element between the first and second doped layers. This structure includes conductive blocks with a tunneling layer that enables controlled leakage current to bypass shaded regions, preventing charge accumulation and hot spot formation while maintaining the IBC module's high power density capabilities
Solution Approach 2:
The patent modifies the electrical parameters of the IBC structure by introducing variable resistance characteristics through the tunneling layer. By controlling the tunneling resistance in the leakage conductive structure, the system can dynamically adjust current distribution to prevent hot spots while preserving overall power output
2Ease of manufacture
If conventional IBC structures are used without leakage paths, then manufacturing is simpler, but hot spot effects cause significant power loss
Solution Approach 1:
The patent divides the back contact structure into separate first and second doped layers with distinct functions. The leakage conductive structure is segmented into conductive blocks positioned at specific locations, allowing independent optimization of each segment while maintaining overall manufacturing feasibility through modular construction
3Reliability
If precise alignment of conductive blocks is required for optimal performance, then leakage current control improves, but manufacturing precision requirements increase
Solution Approach 1:
The conductive blocks are designed to serve multiple functions: providing leakage current paths, establishing electrical connections between doped layers, and offering mechanical support. This multi-functionality reduces the need for extremely precise alignment while maintaining reliable leakage current control through the tunneling layer
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 design alleviates hot spot phenomena by establishing a leakage current path, minimizing local current concentration and enhancing manufacturing feasibility through reduced precision requirements.
Implementation Method 1
the leakage conductive structure includes a first conductive block, a second conductive block, and a leakage tunneling layer, the first conductive block is connected to the first doped layer, and the second conductive block is connected to the second doped layer, the first conductive block and the second conductive block are at least partially overlapped, and the leakage tunneling layer is provided between the first conductive block and the second conductive block
Data Source
AI summary
An IBC solar cell includes a silicon substrate, a first doped layer, a second doped layer, and a leakage conductive structure, wherein the first doped layer and the second doped layer are spaced apart on a backside of the silicon substrate, doping types of the first doped layer and the second doped layer are different, an isolation region is provided between the first doped layer and the second doped layer; the leakage conductive structure includes a first conductive block, a second conductive block, and a leakage tunneling layer, the first conductive block is connected to the first doped layer, and the second conductive block is connected to the second doped layer, the first conductive block and the second conductive block are at least partially overlapped, and the leakage tunneling layer is provided between the first conductive block and the second conductive block.