Sequential Perovskite Deposition for Precise Mixed-Halide Stoichiometry
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Solution Overview
Problem
Existing methods for synthesizing complex multicomponent perovskites, particularly mixed halide perovskites, face challenges in controlling stoichiometry and forming impure phases due to the varying and complex precursor materials, leading to instability and poor film quality, especially when using sequential deposition techniques.
Innovation Solution
A method involving sequential physical vapor deposition (PVD) of distinct precursors, including metal and organic halide precursors, with optional annealing steps, to form high-quality, phase-pure perovskite films by separating the deposition of different halide components and allowing for inter-step adjustability, facilitating scalable and uniform film production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If co-evaporation methods are used to synthesise multicomponent perovskites, then multiple halide components can be deposited simultaneously, but control over deposition rates and stoichiometry becomes challenging and expensive
Solution Approach 1:
The patent divides the deposition process into separate sequential steps for different halide components (e.g., depositing PbI2 layer, then PbBr2 layer, then PbCl2 layer) rather than co-evaporating all components simultaneously. This segmentation allows independent control of each deposition step, ensuring precise stoichiometry while maintaining productivity through automated sequential processing.
2Manufacturing precision
If sequential deposition is used to improve stoichiometry control, then phase purity can be achieved, but the process requires more steps and time
Solution Approach 1:
The patent performs preliminary actions by depositing each halide component in separate pre-planned steps with controlled thicknesses, allowing the final perovskite phase to form with correct stoichiometry without requiring extensive post-deposition processing or annealing time, thus achieving phase purity efficiently.
3Adaptability or versatility
If complex multicomponent perovskites are synthesised with varying precursor materials, then material performance can be optimized, but impurity phases and instability increase
Solution Approach 1:
The patent systematically changes deposition parameters (temperature, pressure, deposition rate, layer thickness) for each halide component to optimize the final perovskite composition and performance while maintaining film stability through precise control of these parameters during sequential deposition.
4Ease of manufacture
If solution processes are used for making complex multicomponent perovskites, then synthesis is easier, but scalability and damage to pre-existing device layers are concerns
Solution Approach 1:
The patent replaces solution-based chemical processes with physical vapor deposition methods, eliminating the need for solvents, spin-coating, and thermal annealing that damage underlying layers. This substitution maintains ease of manufacture through automated deposition while dramatically improving scalability for industrial production.
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 method produces highly crystalline and uniform perovskite films with reduced impurities, enhancing device performance and enabling large-scale industrial production of complex perovskite structures suitable for photovoltaic applications.
Implementation Method 1
The deposition of a first metal halide precursor; and the deposition of a second metal halide precursor... wherein steps i., ii. and iii. (if present) are carried out by physical vapour deposition
Implementation Method 2
with optional annealing steps, to form high-quality, phase-pure perovskite films
Data Source
AI summary
The invention provides a method for producing a perovskite material which comprises: i. The deposition of a first metal halide precursor; and ii. The deposition of a second metal halide precursor, wherein the halide component in the second metal halide precursor is different from that of the first metal halide precursor and the first and second metal halide precursors are deposited separately; and iii. The deposition of an inorganic halide precursor; and/or iv. The deposition of a first organic halide precursor; and v. Optionally, the deposition of a second organic halide precursor which is different from the first organic halide precursor; and vi. Optionally, the deposition of a third organic halide precursor which is different from the first and second organic halide precursors; to form the perovskite material which comprises a mixed halide; wherein steps i., ii., and iii., when present, are carried out by physical vapour deposition.