Wide-Bandgap Perovskite Layer With Bromide Gradient for Tandem Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for perovskite compositions and methods to enhance the efficiency of tandem solar cells by achieving higher power conversion efficiency, particularly through the development of wide bandgap perovskite materials that improve the utilization of solar light.
Innovation Solution
A method involving a perovskite layer with a bulk composition of AB(X1-yXy′)3, where A and B are specific cations, X is iodide, and X′ is bromide, with a bromide concentration gradient, is used. This layer is formed through a gas-quench process that includes a perovskite precursor solution containing bromide and iodide, resulting in a solid perovskite layer with enhanced properties such as a bandgap greater than 1.5 eV and a textured columnar structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional perovskite compositions and methods are used, then manufacturing simplicity is maintained, but power conversion efficiency and stability are insufficient
Solution Approach 1:
The patent employs parameter changes by precisely controlling the bromide concentration gradient (y values between 0.2-0.8 at different positions) and processing parameters (temperature 20-100°C, pressure 20-70 psig, time 1 second to 1 hour) to achieve wide bandgap perovskite with enhanced efficiency while maintaining solution processing simplicity
Solution Approach 2:
The patent applies local quality by creating a spatially varying bromide concentration gradient within the perovskite layer, where the composition varies from y=0.2 to y=0.8 across the layer thickness, enabling different regions to contribute differently to light absorption and charge transport for optimized overall performance
2Productivity
If wide bandgap perovskite materials are developed to improve solar light utilization, then power conversion efficiency increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies preliminary action by pre-designing the bromide concentration gradient in the precursor solution formulation, which automatically establishes the desired compositional profile during gas-quench processing, eliminating the need for complex post-processing adjustments and ensuring reproducible wide bandgap perovskite formation
Solution Approach 2:
The patent uses the gas-quench process as an intermediary mechanism that mediates between the precursor solution composition and the final perovskite structure, enabling precise control of the bromide concentration gradient through controlled gas exposure that facilitates rapid solvent removal and uniform crystallization
3Reliability
If perovskite layers with bromide concentration gradient are formed, then device stability and efficiency are improved, but the processing complexity increases
Solution Approach 1:
The patent applies self-service by designing a self-organizing gas-quench process where the controlled removal of solvent from the precursor solution automatically induces the formation of the desired bromide concentration gradient and perovskite crystalline structure, eliminating the need for complex external control mechanisms during processing
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 approach results in perovskite solar cells with improved power conversion efficiency, stability, and reproducibility, achieving over 20% power conversion efficiency and maintaining efficiency under various temperature and illumination conditions, with a tandem device reaching 27.1% efficiency.
Implementation Method 1
the contacting results in the transforming of the liquid layer to a solid perovskite layer
Implementation Method 2
This layer is formed through a gas-quench process that includes a perovskite precursor solution containing bromide and iodide
Implementation Method 3
Perovskite solar cells (PSCs) have reached certified 25.5% power conversion efficiency (PCE) for single-junction devices
Data Source
AI summary
The present disclosure relates to a device that includes a layer that includes a perovskite, where the layer has a first side and a second side defining a thickness, the perovskite has a bulk composition as defined by AB(X1-yXy′)3, where A includes a first cation, B includes a second cation, X includes iodide, and X′ includes bromide, y is between 0.2 and 0.8, inclusively, and the thickness has a bromide concentration gradient across the thickness with a maximum concentration at or in the proximity of the first side and a minimum concentration at the second side.