Gas-Assisted Spray Fabrication of Reticulated TiO₂ Scaffolds for Perovskite Solar Applications

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Perovskite solar cells (PSCs) are promising for next-generation photovoltaics.
• Efficient electron transport layers (ETLs) are crucial for high-performance PSCs.
• Current ETL fabrication methods face challenges in scalability and uniformity.

Purpose of the Study:

• To investigate spray deposition for engineering titanium dioxide (TiO2) ETLs in PSCs.
• To analyze the morphological and performance impacts of spray-coated c-TiO2 and m-TiO2 films.
• To optimize spray deposition parameters for enhanced PSC efficiency and stability.

Main Methods:

• Sequential fabrication of compact (c-TiO2) and mesoporous (m-TiO2) films using spray deposition.
• Characterization of film morphology, roughness, and interfacial properties.
• Fabrication and performance testing of PSCs with spray-deposited ETLs, including efficiency and hysteresis measurements.

Main Results:

• Spray coating produced TiO2 films with a unique reticulated morphology and significantly increased surface roughness compared to spin-coated films.
• Optimized spray deposition of m-TiO2 layers led to enhanced interfacial area, facilitating efficient charge transfer.
• Improved power conversion efficiency (PCE), reduced series resistance, and minimized hysteresis were observed in PSCs with spray-deposited ETLs.
• Optimal film thickness was found to be critical for perovskite anchoring and device performance, balancing light transmission and sheet resistance.

Conclusions:

• Spray deposition is a viable and scalable technique for fabricating high-performance ETLs in PSCs.
• Engineered TiO2 morphology via spray coating significantly boosts charge transfer and overall device efficiency.
• This approach offers a promising pathway for the industrial-scale production of efficient and stable perovskite solar cells.