Toward scale-up of perovskite solar cells: Annealing-free perovskite layer by low-cost ultrasonic substrate vibration of wet films

• Published in: Materials today communications 2018-03, Vol.14, p.151-159
• Main Authors: Ahmadian-Yazdi, Mohammad-Reza, Eslamian, Morteza
• Format: Article
• Language: English
• Subjects: Annealing-free; Anti-solvent-free; Perovskite solar cells; Scale-up; Ultrasonic substrate vibration post treatment
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2018.01.006

[Display omitted] •Annealing-free perovskite solar cells are developed using ultrasonic excitation of wet films.•Ultrasonic vibration for 3 min excites the wet film, creates micromixing and in-situ annealing.•The device efficiency is 14%.•Annealing-free, anti-solvent free devices with efficiency of 10% are also developed.•Removing the costly annealing step is important for scale-up of the technology. Perovskite solar cells (PSCs) have achieved compelling power conversion efficiencies (PCE), but at the expense of employing costly processes and treatments, which alongside the inadequate stability and lifetime, hinder the scale-up of this technology. This paper studies the possibility of fabricating annealing-free, anti-solvent-free PSCs, to pave the way for the commercialization of the technology through reducing the fabrication steps and costs. To this end, the as-spun wet perovskite films are subjected to ultrasonic vibration for the optimum duration time of 3 min, where the vibration controls the crystal growth and serves as an in-situ annealing step, eliminating the need for an additional post treatment step. The annealing-free PSCs with anti-solvent treatment show a PCE of 14.09%, whereas the annealing-free, anti-solvent-free devices show a PCE of 10.43%, demonstrating the merit of the novel approach used in this work for low-cost fabrication of PSCs. The ultrasonic vibration treatment is compatible with other perovskite formulations that yield higher PCEs, as well as scalable deposition techniques, such as spray, blade, and slot-die coating.