Perovskite Photoactive Layer Coating for Uniform Crystal Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The large-scale production of perovskite solar cells is hindered by the difficulty in forming a uniform photoactive layer due to rapid crystallization of perovskite crystals during the coating process, leading to issues like dewetting, non-homogeneous crystal formation, and pinhole formation.
Innovation Solution
Incorporating a polymer additive into the perovskite precursor solution as a crystallization retardant, which slows down the crystallization process, allowing for the formation of a uniform crystal structure, and can be removed without affecting the electro-active properties of the layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If spin coating is used to form perovskite photoactive layer, then homogeneous film formation is achieved, but large-scale production is not feasible
Solution Approach 1:
The patent extracts the perovskite precursor from its traditional solvent system and incorporates it into a polymer matrix to form an ink composition. This extraction of the active component and placement into a new carrier system enables the material to be applied using conventional printing techniques while maintaining film quality, thus resolving the contradiction between film uniformity and production scale.
Solution Approach 2:
The patent introduces a polymer as an intermediary carrier that holds the perovskite precursor. This polymer intermediary enables the precursor to be deposited using scalable printing methods while still forming uniform films after processing, bridging the gap between lab-scale spin coating and industrial production requirements.
2Productivity
If wet coating methods are used for large-scale production, then productivity is improved, but dewetting and pinhole formation occur due to rapid crystallization
Solution Approach 1:
The patent performs preliminary action by incorporating the perovskite precursor into a polymer matrix before deposition. This pre-formulation stabilizes the precursor and controls its release during processing, preventing rapid crystallization and associated defects like dewetting and pinholes, thus enabling both large-scale production and film uniformity.
Solution Approach 2:
The patent changes the physical and chemical parameters of the precursor formulation by dissolving it in a polymer matrix rather than using traditional volatile solvents. This parameter change slows down the crystallization kinetics, allowing wet coating methods to be used at scale without the rapid crystallization that causes film defects.
3Productivity
If perovskite precursor solution is applied rapidly, then productivity is improved, but non-homogeneous crystal formation occurs
Solution Approach 1:
The polymer acts as an intermediary that mediates between the rapid deposition process and the slow crystallization requirement. It allows fast coating application while controlling the subsequent crystallization to produce uniform structures, thus resolving the contradiction between coating speed and crystal uniformity.
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 use of a polymer additive enables the formation of a uniform photoactive layer, improving the processability and efficiency of perovskite solar cells by controlling crystallization rates and preventing defects such as pinholes, thereby enhancing the overall performance of the solar cells.
Implementation Method 1
formation of a photoactive layer of perovskite crystals undergoes rapid crystallisation when applied to a substrate
Implementation Method 2
a wet film of coating material is formed first and then dried
Data Source
Figure 1A~2B
Figure 3
AI summary
A process of forming a thin film photoactive layer of a perovskite photoactive device comprising: applying at least one coating of a perovskite precursor solution and a polymer additive to a substrate, wherein the at least one perovskite precursor solution comprises at least one reaction constituent for forming at least one perovskite compound having the formula AMX3 dissolved in a coating solvent selected from at least one polar aprotic solvent, the polymer additive being soluble in said coating solvent, and in which A comprises an ammonium group or other nitrogen containing organic cation, M is selected from Pb, Sn, Ge, Ca, Sr, Cd, Cu, Ni, Mn, Co, Zn, Fe, Mg, Ba, Si, Ti, Bi, or In, and X is selected from at least one of F, Cl, Br or I.