Excitation of Wet Perovskite Films by Ultrasonic Vibration Improves the Device Performance

Abstract

Abstract:In this work, a novel, facile, and low-cost mechanical post treatment technique, i.e., ultrasonic substrate vibration post treatment (SVPT) is applied on wet spun perovskite layers. The effect of varying the time of the SVPT on the characteristics of the perovskite crystals and the perovskite film is studied, in order to achieve the optimum time duration of the SVPT. Among the results, it is found that the application of only three minutes of the SVPT (for the ultrasonic vibration assembly used in this study, operated at 40 kHz) brings about significant improvement in the film coverage, and the contact between the perovskite and the m-TiO 2 layers, owing to the effective penetration of the perovskite solution into the pores, leading to a superior charge transfer, and a significant increase in the device power conversion efficiency (PCE), when compared to the control device. This unprecedented effect is repeatable when applied on both single and mixed halide perovskites, putting forward a reliable and low-cost mechanical technique for the fabrication of perovskite solar cells (PSCs) in the lab and beyond, which could reduce or eliminate the tedious and expensive chemical optimization treatments, commonly used to increase the PCE.

Microstructural and Nanostructural Evolution of Light Harvester Perovskite Thin Film under the Influence of Ultrasonic Vibrations

“…So far, these results have shown that the solvent depletes and the interfacial energy of perovskite films decreases with increasing the time of imposed ultrasonic vibrations. In addition, in previous studies, it has been shown that ultrasonic vibrations result in an improvement in the perovskite light absorption 8 and a decrease 25 or increase 9 in the grain size, depending on the choice of the substrate and solutions, as discussed in the Introduction section. The aforementioned effects may be because of the variations in the nucleation and crystallization of the perovskite, under the presence and varying time of ultrasonic vibrations.…”

“…8 This method has also shown applicability to other solution-processed materials, for example, improvement of physical and chemical properties of graphene−TiO 2 , 20 ZnO, 24 and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate 16 thin films. Ahmadian-Yazdi et al 25 performed ultrasonic vibrations on mesoporous structured PSCs before annealing on single and mixed-halide perovskites, and their results demonstrated substantial film coverage and charge-transfer improvement. In another study, Ahmadian-Yazdi et al 8 eliminated the annealing process for perovskite thin-film processing by employing diethyl ether (DEE) as an antisolvent for n-methyl-2-pyrrolidone (NMP) during spin casting.…”

Samarium-Doped Metal Halide Perovskite Nanocrystals for Single-Component Electroluminescent White Light-Emitting Diodes

“…Meanwhile, the Sm 3+ iondoped CsPbCl 3 PeNC film maintain optical performance similar to that of its corresponding PeNCs and exhibit only a partial decrease of PLQY in the film owing to the aggregation of the particles in the film (Figure S15). 43,44 The normalized EL spectra of the as-prepared PeLED devices based on Sm 3+ ion-doped PeNCs with concentrations of 2.6 mol %, 5.1 mol %, and 10.3 mol % are depicted in Figure 4b. It is found that there is an obvious inhomogeneous broadening in EL versus PL.…”

Effect of Marangoni Convection on the Perovskite Thin Liquid Film Deposition

“…Moreover, to improve the thin-film deposition characteristics, an emerging fabrication method compatible with the solution processing has been systematically surveyed, which will be employed and further studied in this paper. Ultrasonic vibration is an effective method for thin-film fabrication which has the potential to be employed to deposit relatively large-area and uniform films and coatings ,, if the frequency and amplitude are well chosen. Imposing ultrasonic vibrations results in bulk and local micromotions in the fluid, , a flow that will interact with Marangoni-induced flows, as previously discussed.…”