Low-voltage room-temperature electrochemical deposition of perovskite films for solar cell devices

A uniform CH3NH3PbI3 layer was successfully deposited on a mesoporous TiO2 layer (mp-TiO2) via a two-step low-voltage room-temperature electrochemical deposition method without annealing. The deposited perovskite crystals were applied to cover a surface mp-TiO2 electron transport material and fill the nanoscale blank of mp-TiO2. A mesoporous electron transport material and a platinum sheet were used as working and counter electrodes, respectively. The obtained film was then utilized to fabricate a mesoporous hybrid perovskite solar cell (PSC) with the configuration of a fluorine-doped tin oxide/compact TiO2/mp-TiO2/perovskite/Spiro-OMeTAD/Au electrode. An efficiency of 15% was achieved by adjusting Pb and MAI deposition and by using champion cells with an active area of 2 mm x 2 mm at 1 sun under an AM 1.5 condition. The perovskite layers and PSCs were analyzed through several characterization methods. Results demonstrated that this deposition technology could be applied to easily control the morphological characteristics of perovskite layers. Thus, a high power conversion efficiency was obtained. This study proposed a possible perovskite deposition process and demonstrated that electrochemical deposition could have potential for application in PSC fabrication.