Multilayer Composite Transport Layer for Stable Perovskite Hole Extraction
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Solution Overview
Problem
Perovskite solar modules with inverted structures face lower conversion efficiency and stability issues due to energy band mismatches and high defect densities at interfaces, particularly in the hole transport layer, and fluorine-doped tin oxide materials can degrade perovskite materials over time.
Innovation Solution
A multilayer composite transport layer is introduced, comprising a blocking graded layer, a graded layer, a hole transport layer, and a buffer layer, with specific doping and coupling agents to enhance stability and efficiency, using materials like fluorine-doped tin oxide and inorganic oxides, and incorporating coupling agents to form molecular clusters and openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inorganic oxide materials (e.g., NiO x ) are used for the hole transport layer to achieve low cost and ease of manufacture, then conversion efficiency can be improved through high defect density, but stability deteriorates due to photothermal degradation at the interface
Solution Approach 1:
The hole transport layer is segmented into multiple sub-layers with different compositions and functions. The first hole transport layer uses inorganic oxide for hole extraction, while the second hole transport layer uses organic material for stability and interface protection. This segmentation allows each layer to optimize its specific function without compromising overall device performance.
Solution Approach 2:
The invention employs a composite structure combining inorganic oxide and organic materials in the hole transport layer. This composite approach leverages the advantages of both material types: the low cost and ease of manufacture of inorganic oxides, and the superior stability and interface compatibility of organic materials.
2Productivity
If high defect density is introduced in the hole transport layer to improve hole mobility and conversion efficiency, then conversion efficiency is improved, but stability worsens due to increased interface defects
Solution Approach 1:
The hole transport function is divided between two layers: the first layer (inorganic oxide) provides high defect density for efficient hole extraction and high conversion efficiency, while the second layer (organic material) provides a stable, low-defect interface with the perovskite layer, preventing the stability issues that would otherwise result from high defect density.
3Reliability
If fluorine-doped tin oxide is used for the transparent conductive layer to achieve good electrical conductivity, then electrical conductivity is improved, but stability worsens due to fluorine migration into the perovskite layer
Solution Approach 1:
An intermediate layer is introduced between the fluorine-doped tin oxide transparent conductive layer and the perovskite layer. This intermediate layer acts as a barrier to prevent fluorine migration into the perovskite, while maintaining good electrical conductivity and energy band alignment, thus preserving both the electrical performance and long-term stability.
4Reliability
If inorganic oxide hole transport layer is made with dense structure to improve material stability, then stability is improved, but conversion efficiency worsens due to poor hole conduction
Solution Approach 1:
The hole transport function is segmented between two layers: the first layer provides a dense structure for stability, while the second layer provides optimized porosity and composition for efficient hole conduction. This segmentation allows the dense first layer to ensure stability without compromising the hole transport performance of the overall structure.
Data Source
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AI summary
The present disclosure relates to a multilayer composite transport layer, including a blocking graded layer, a graded layer, a hole transport layer, and a buffer layer stacked in sequence along a light incidence direction. A preparation material of the blocking graded layer is fluorine-doped tin oxide doped with element R to replace element F, with a replacement ratio of the element R to the element F ranging from 1% to 100%. The element R is at least one element of W, Nb, Ni, Al, or Si. A preparation material of the graded layer is NixAySizSnmOn or CuxAySizSnmOn, where x>0, y>=0, z>=0, m>=0, n>0, and A is aluminum (Al) or boron (B). A preparation material of the hole transport layer is one of NiOx, CuxO, or CuSCN. A preparation material of the buffer layer is NiaEbNcOd or CuaEbNcOd, where a>0, b>=0, c>0, d>=0, and E is one element of Al, B, Si, Zn, Co, or Zr. The present disclosure provides a perovskite solar module using the multilayer composite transport layer, and a preparation method thereof, this enables the perovskite solar module to achieve both high conversion efficiency and excellent long-term photothermal stability.