Slot-Die-Coated Zinc Tin Oxide Film for Carbon-Based Methylammonium-Free Perovskite Solar Cells

Abstract

At the laboratory scale, the spin coating technique is commonly used for depositing an electron transporting layer (ETL) in perovskite solar cells (PSCs). However, this technique is unsuitable for scaling up production. To enable large-scale deposition, slot-die coating, — a promising scalable technique and low operational cost processing, — has been proposed for depositing thin and uniform films across large areas. In this work, scalable slot-die coating processes of amorphous zinc tin oxide (ZTO) as ETLs are illustrated for carbon-based methylammonium-free PSCs. The amorphous ZTO was selected because of its excellent optical and electronic properties such as high electrical conductivity, high electron mobility, and high transparency. Slot-die-coated ZTO thin films were prepared from a proprietary homemade slot-die setup on a 3-axis computer numerical control (CNC) platform. Various thicknesses of ZTO thin films were utilized by changing the speed of the slot-die head. The device using slot-die-coated ZTO films with a film thickness of 48[Formula: see text]nm was found to exhibit the best device maximum power conversion efficiency of 9.92%, which is comparable to that of the device using spin-coated ZTO film. This work demonstrates the potential of the slot-die coating technique to replace the conventional spin-coating method in the fabrication of high efficiency and scalable PSCs.

Efficient and Stable Carbon-Based Perovskite Solar Cells Enabled by Mixed CuPc:CuSCN Hole Transporting Layer for Indoor Applications

“…Zinc tin oxide (ZTO) thin film as an ETL was prepared on a fluorine tin oxide (FTO) substrate by the sol–gel method. , Briefly, FTO substrates were first cleaned by ultrasonic sonication in an Alconox detergent solution, deionized water (DI), acetone, and isopropanol for 30 min, respectively. The washed FTO substrates were then dried on a hot plate at 125 °C for 15 min before ultraviolet–ozone (UVO) treatment for 30 min.…”

Functional Materials for Fabrication of Carbon-Based Perovskite Solar Cells: Ink Formulation and Its Effect on Solar Cell Performance

“…Furthermore, the controllable substrate temperature can impact the quality of the film. The inks/pastes used in these processes usually require large amounts of binders and thickeners to produce the high viscosities (1000-10,000 mPa s) required for repro- [141]. The device was produced with a homemade slot-die system, and the inks used were prepared from commercial materials.…”

“…Schematic illustration of the main components in a slot-die processing set-up. Khambunkoed et al fabricated carbon-based methylammonium-free PSCs in 2021, utilizing amorphous zinc tin oxide (ZTO) as the ETL[141]. The device was produced with a homemade slot-die system, and the inks used were prepared from commercial materials.…”

Improvement in reproducibility of large-scale perovskite solar cells using automatic liquid injection in antisolvent method

“…Before use, the solution was stirred at room temperature for 2 h and aged for 24 h. By spin-coating at 3000 rpm for 30 s, ZTO ETLs were deposited to the cleaned FTO substrates. The substrate was annealed for one hour at 450 °C on a hotplate [4].…”