Al-Doped TiO2 Nanoparticles for Low-Temperature Solar Cell Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of TiO2 electron transport layers in perovskite solar cells requires high temperatures and is incompatible with flexible substrates or certain electrodes, limiting their industrial scalability and versatility due to the use of polar solvents and high annealing temperatures.
Innovation Solution
A method for forming doped TiO2 nanoparticles using a non-aqueous composition with a polar solvent and a titanium(IV) halide, followed by heating and stirring to create hazy nanoparticles, which are then sintered at lower temperatures to form a pinhole-free film suitable for both normal and inverted photovoltaic cell architectures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If solution processing of TiO2 layer is used, then manufacturing cost and complexity are reduced, but the layer cannot resist subsequent processing with polar solvents and requires very high temperature annealing
Solution Approach 1:
The invention changes the chemical composition parameters of the TiO2 layer by incorporating aluminum dopant atoms into the TiO2 crystal structure. This compositional modification fundamentally alters the layer's properties, enabling it to resist polar solvents used in perovskite processing while maintaining solution processability and reducing annealing temperature requirements from 500-600°C to below 400°C.
2Strength
If very high annealing temperatures (500-600°C) are used for TiO2 layer, then layer density and resistance to polar solvents are improved, but compatibility with flexible substrates and certain electrodes is lost
Solution Approach 1:
The invention modifies the chemical composition by doping TiO2 with aluminum, which changes the thermal processing parameters required. The Al-doped TiO2 achieves the necessary density and solvent resistance at annealing temperatures below 400°C, thereby maintaining compatibility with flexible substrates and temperature-sensitive electrodes that cannot withstand 500-600°C processing.
3Reliability
If TiO2 layer is made thick, hard and dense to resist polar solvents, then processing resistance is improved, but electrical conductivity decreases
Solution Approach 1:
The invention changes the chemical composition by incorporating aluminum dopant atoms into the TiO2 structure. This compositional change simultaneously improves solvent resistance and enhances electrical conductivity through dopant-induced charge carriers, eliminating the trade-off where thicker, denser layers would normally reduce conductivity.
Solution Approach 2:
The invention creates a composite material system by doping TiO2 with aluminum, forming Al-doped TiO2 with distinct compositional regions at the nanoscale. This composite approach combines the solvent resistance of dense TiO2 with the enhanced conductivity provided by aluminum dopant sites, achieving both properties simultaneously.
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 enables the creation of high electrical conductivity TiO2 films that resist processing with polar solvents, allowing for efficient and scalable production of electron transport layers without the need for high temperatures, thereby improving the performance and versatility of perovskite solar cells.
Implementation Method 1
forming the doped TiO2 nanoparticles in the non-aqueous composition by heating and stirring the non-aqueous composition
Implementation Method 2
forming the doped TiO2 nanoparticles in the non-aqueous composition by heating and stirring the non-aqueous composition
Implementation Method 3
forming the doped TiO2 nanoparticles in the non-aqueous composition by heating and stirring the non-aqueous composition
Implementation Method 4
which are then sintered at lower temperatures to form a pinhole-free film
Data Source
Figure 1~2
Figure 3
AI summary
A non-aqueous composition for forming doped ΤiΟ2 nanopartides, comprising: i. a polar solvent comprising an organic compound having one or more oxygen atoms in its chemical structure, ii. a titanium(IV) halide, and iii. a dopant precursor selected from transition metal halides and lanthanide halides.