Perovskite-Silicon Tandem Interface Design to Reduce Voltage Loss
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Solution Overview
Problem
Tandem photovoltaic devices experience current and voltage loss due to higher parasitic absorption and interface resistance caused by multilayer electrical function layers, leading to lower actual output voltage than theoretical voltage.
Innovation Solution
A tandem photovoltaic device with a perovskite and crystalline silicon absorbing layers connected in series through a single-layer electrical function layer, where the conducting types and work functions at the series interfaces are matched within a specific range (≥−0.3 eV and ≤0.3 eV) to reduce voltage loss and interface resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multilayer electrical function layers are used to connect perovskite and crystalline silicon absorbing layers in series, then energy band buffering and carrier transmission functions are achieved, but parasitic absorption increases and interface resistance increases causing current loss
Solution Approach 1:
The patent removes the multilayer electrical function layer structure and replaces it with a single-layer electrical function layer. This extraction of the problematic multilayer structure eliminates the excessive interfaces that cause parasitic absorption and interface resistance, while still maintaining the necessary energy band buffering and carrier transmission functions through the optimized single-layer design with controlled work function differences (≥−0.3 eV and ≤0.3 eV).
Solution Approach 2:
The patent changes the parameter of electrical function layer structure from multiple layers to a single layer, and controls the work function difference parameter within a specific range (≥−0.3 eV and ≤0.3 eV). This parameter change reduces the number of interfaces and optimizes energy band alignment, thereby reducing parasitic absorption and interface resistance while maintaining carrier transmission efficiency.
2Reliability
If multilayer electrical function layers are used for series connection, then energy band buffering is achieved, but voltage loss increases due to interface resistance and defect loss
Solution Approach 1:
The patent extracts and removes the problematic multilayer electrical function layer structure, replacing it with a single-layer design. This eliminates the multiple interfaces that cause voltage loss through interface resistance and defect loss, while the single-layer structure continues to provide necessary energy band buffering through optimized work function alignment.
Solution Approach 2:
The patent optimizes the work function difference parameter of the electrical function layer to within ≥−0.3 eV and ≤0.3 eV. This parameter change ensures proper energy band alignment between perovskite and crystalline silicon layers, maintaining energy band buffering capability while minimizing voltage loss from interface effects.
3Power
If theoretical voltage sum is achieved in series stack structure, then power conversion efficiency is maximized, but actual voltage is lower due to voltage loss at interfaces
Solution Approach 1:
The patent controls the work function difference parameter within a specific range (≥−0.3 eV and ≤0.3 eV) to optimize energy band alignment. This parameter optimization reduces voltage loss at the series interface, allowing the actual output voltage to approach the theoretical voltage sum of the two devices, thereby maximizing power conversion efficiency.
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 reduces parasitic absorption and interface resistance, enhancing the power conversion efficiency of the tandem photovoltaic device by maintaining optimal energy band structures and minimizing voltage loss.
Implementation Method 1
a perovskite absorbing layer, a crystalline silicon absorbing layer... power conversion efficiency of the tandem photovoltaic device
Data Source
AI summary
A tandem photovoltaic device includes a perovskite absorbing layer, a crystalline silicon absorbing layer and a single-layer electrical function layer connected in series to the two absorbing layers; a contact interface between the perovskite absorbing layer and the single-layer electrical function layer is a first series interface; and a contact interface between the crystalline silicon absorbing layer and the single-layer electrical function layer is a second series interface; wherein a conducting type at the second series interface is different from a conducting type at the first series interface, and the difference between the work functions is ≥−0.3 eV and ≤0.3 eV.