Rapid Scalable Processing of Tin Oxide Transport Layers for Perovskite Solar Cells

Abstract

The development of scalable deposition methods for perovskite solar cell materials is critical to enable the commercialization of this nascent technology. Herein, we investigate the use and processing of nanoparticle SnO2 films as electron transport layers in perovskite solar cells and develop deposition methods for ultrasonic spray coating and slot-die coating, leading to photovoltaic device efficiencies over 19%. The effects of postprocessing treatments (thermal annealing, UV ozone, and O2 plasma) are then probed using structural and spectroscopic techniques to characterize the nature of the np-SnO2/perovskite interface. We show that a brief “hot air flow” method can be used to replace extended thermal annealing, confirming that this approach is compatible with high-throughput processing. Our results highlight the importance of interface management to minimize nonradiative losses and provide a deeper understanding of the processing requirements for large-area deposition of nanoparticle metal oxides.

Potassium iodide reduces the stability of triple-cation perovskite solar cells

“…However, the nanoparticle SnO 2 (np-SnO 2 ) colloidal solution used to prepare the ETL already contained a quantity of K + ions in the form of a KOH stabiliser that was added to the solution by the manufacturer. 39,40 Although the exact concentration of the K + in the np-SnO 2 ETL solution is unknown, we suspect that the addition of even a small quantity ($5%) of KI into the TC precursor solution was sufficient to exceed the "sweet spot" concentration for optimum perovskite grain growth and instead causes a reduction in the average perovskite grain size. We believe that the increased recombination at lateral grain boundaries (in devices containing 5% and 10% KI) together with the presence of secondary non-perovskite phases (in devices containing 20% KI) are signicant contributory factors to the observed decrease in the photovoltaic device efficiency.…”

Fully Spray-Coated Triple-Cation Perovskite Solar Cells

“…The devices fabricated were based on the following planar architecture: ITO/np-SnO 2 /perovskite/ spiro-OMeTAD/Au. Tin oxide layers were deposited from a commercially available nanoparticle dispersion 32 diluted in water, which we have both spin and spray-coated 33 . After deposition, the films were annealed for 30 minutes at 150 °C before being subject to a 15 minute UV ozone treatment.…”

“…www.nature.com/scientificreports www.nature.com/scientificreports/ spraying this layer. For a more in depth analysis of spray-coated np-SnO 2 films we direct the reader to other recent work in which we develop this process 33 .…”

Effects of All‐Organic Interlayer Surface Modifiers on the Efficiency and Stability of Perovskite Solar Cells

“…To demonstrate the capability of our all-organic surface modifier in generating high efficiency devices, we carried out our investigation by using BAB as HPs defect passivator in fabrication of solar cells with planar n-i-p structure, where thin layer of SnO 2 was used as the electron transporting layer (Figure 5a). [67][68][69] Statistical representations of individual photovoltaic parameters of 15 devices, based on pristine and treated samples, are depicted in (Figures 5b-e). In general, consistent with the statistical data of the devices with mesoporous configuration presented earlier, the passivated devices in average exhibit better V oc (1090 � 15 vs. 1071 � 14 mV) and FF (74.09 � 1.17 vs. 73.50 � 2.05 %) while retaining good J sc (22.21 � 0.28 vs. 21.37 � 0.71 mA cm À 2 ).…”