Optimizing Perovskite Solar Cell Architecture in Multistep Routes Including Electrodeposition

Abstract

The electrodeposition technique was explored as a powerful method for perovskite fabrication. It possesses the ability to elaborate high-quality perovskite layers on large-size substrates, with minimal manufacturing costs. In this work, the electrodeposition of PbO2 was conducted as a first step to elaborate MAPbI3 perovskite layers. Two conversion routes have been considered to reach the perovskite film. The first one is an immediate conversion of PbO2 into PK1 by immersion in methylammonium iodide (MAI, CH3NH3I) solution. The second route is a two-step conversion: initial PbO2 conversion into PbI2 by immersion in hydrogen iodide (HI), followed by PbI2 conversion into PK2 by immersion in MAI. For further evaluation of the impact of the conversion pathway and the nature of the substrate, an in-depth study of the microstructure, the morphology, and the key properties for the application of the perovskite layers has been conducted using a set of dedicated characterization techniques. Perovskite solar cells have also been developed using the electrodeposited active layers, which opens the way to promising performances using electrodeposition.

The role of Pb oxidation state of the precursor in the formation of 2D perovskite microplates

“…A similar reaction pathway is not possible with PbO 2 due to the Pb 4+ oxidation state. Based on our observations and existing literature on dissolution of Pb-precursors 60 we suggest the following chemical reaction pathway during the BAI : IPA exposure of PbO 2 . First, the PbO 2 precursor undergoes a spontaneous primary redox step with I − that yields Pb 2+ , triiodide (I 3 − ), butylamine (C 4 H 9 NH 2 ) and water into the solution as follows:which is then succeeded by the complexation of Pb 2+ ions into high-valent iodoplumate species via Pb 2+ + 3I − ⇌ PbI 3 − orPb 2+ + 4I − ⇌ PbI 4 2− …”

Improvement in Efficiency and Reproducibility for FAPbI3 Solar Cells with Rapid Crystallization

“…Generally, the perovskite film preparation methods include spin coating, drop casting, thermal evaporation, pulsed laser deposition, blade coating, spray coating, electrodeposition, etc. − Among all of these fabrication methods, the electrodeposition method is a cost-effective, large-scalable, highly reproducible, environmentally friendly, and flexible fabrication technique, which will have a place in the large-scale manufacturing process for perovskite solar cells in the future. At the same time, with the continuous in-depth study of the electrodeposition method in recent years, some exciting achievements have been obtained. − …”

“…When the second stage is changed to vapor conversion, the PbO 2 film can also be used to react with HI vapor for the conversion of PbI 2 , which was then exposed to CH 3 NH 3 I vapor for the synthesization of the CH 3 NH 3 PbI 3 film. , Lee et al used the PbO 2 film to react with the gas of 4% H 2 /Ar for the conversion of PbO, which can also be exposed to CH 3 NH 3 I vapor for the synthesization of the CH 3 NH 3 PbI 3 film. , Besides, by immersion of the PbO 2 film into the solution of CH 3 NH 3 I/isopropanol, the CH 3 NH 3 PbI 3 film can also be obtained directly through the reaction of PbO 2 and CH 3 NH 3 I at temperatures from −2 to 75 °C, where the as-grown CH 3 NH 3 PbI 3 film begins to dissolve apparently at a temperature of ∼55 °C . Katrib et al also used electrodeposited PbO 2 for converting mixed halide perovskites, and the record efficiency of the corresponding perovskite solar cells can be improved to 10% with an optimized solar cell architecture, chlorine addition, and carbon electrode. − In addition to PbO 2 , it has been reported that the electrochemical synthesis of PbI 2 , PbO, , PbS, , and metal Pb , can also provide the lead source for the synthesized perovskite CH 3 NH 3 PbI 3 film. By optimization of the electrochemical deposition parameters, the power conversion efficiency (PCE) of the electrodeposited perovskite CH 3 NH 3 PbI 3 solar cells was rapidly improved from 10.19% to 15.65% .…”

Simulation and Verification of the Direct Current Electric Field on Fabricating High Porosity f-MWCNTs Thin Films by Electrophoretic Deposition Technique

“…The electrophoretic deposition (EPD) technique is known to have the advantages of low-temperature operation, controllable layer thickness, short formation time, simple equipment, low cost, various substrate-shape, binder-free, and high scalability potential for large dimensions. − Therefore, the EPD technique is emerging as a potential deposition method for highly ordered structure films that could replace the CVD method. − The EPD technique uses an electric field to move charged particles dispersed in a suitable solvent toward an oppositely charged electrode . This technique can be applied to any solid in particulate form with small particle sizes (<30 μm) and to colloidal suspensions. , The EPD technique can also easily control the morphology and thickness of the deposited layer by adjusting the process parameters . CNTs and perovskite nanocrystals are required to be well-dispersed to make the EPD process successful.…”