Solvent Toolkit for Electrochemical Characterization of Hybrid Perovskite Films

Abstract

Organohalide lead (hybrid) perovskites have emerged as competitive semiconducting materials for photovoltaic devices due to their high performance and low cost. To further the understanding and optimization of these materials, solution-based methods for interrogating and modifying perovskite thin films are needed. In this work, we report a hydrofluoroether (HFE) solvent-based electrolyte for electrochemical processing and characterization of organic-inorganic trihalide lead perovskite thin films. Organic perovskite films are soluble in most of the polar organic solvents, and thus until now, they were not considered suitable for electrochemical processing. We have enabled electrochemical characterization and demonstrated a processing toolset for these materials utilizing highly fluorinated electrolytes based on a HFE solvent. Our results show that chemically orthogonal electrolytes based on HFE solvents do not dissolve organic perovskite films and thus allow electrochemical characterization of the electronic structure, investigation of charge transport properties, and potential electrochemical doping of the films with in situ diagnostic capabilities.

Electrochemistry and Spectroelectrochemistry of Lead Halide Perovskite Films: Materials Science Aspects and Boundary Conditions

“… 11 − 13 In another recent paper, a solvent toolkit was proposed for these Li + intercalation experiments. 16 A very thorough study investigated the electron injection process into formamidinium lead halide perovskite using spectroelectrochemistry. 17 It was demonstrated in this study that it is very difficult, yet possible, to probe band edge positions via charge carrier injection.…”

Sustainable and Self‐Enhanced Electrochemiluminescent Ternary Suprastructures Derived from CsPbBr3 Perovskite Quantum Dots

“…However, in contrast with the prosperous applications of LHP nanomaterials in optoelectronic and photovoltaic areas, their electrochemical studies, let alone ECL investigations, still lag behind. The infancy of LHP electrochemistry is basically attributable to the poor structural stability, which mostly results from either polymorphic transformation, oxidation, or their combination, against external environment such as light, humidity, oxygen, or high temperature, particularly in polar solvents and electrolytes which are necessary to electrochemical measurements . As a result, it is only recently that ECL from either hybrid organic–inorganic or all‐inorganic LHP nanomaterials has been reported .…”

Design of Active Defects in Semiconductors: 3D Electron Diffraction Revealed Novel Organometallic Lead Bromide Phases Containing Ferrocene as Redox Switches

“…Cyclic voltammograms (CV) are recorded to study the oxidation of Fc-containing materials, as they provide information about the redox process of the Fc-ligands and the electronic processes in the material. A suitable electrolyte for the electrochemical characterization of hybrid perovskites is a mixture hydrofluoroether (HFE) and diethyl carbonate (DEC) with lithium bistrifluoromethane sulfonimidate (LiTFSI), proposed by Hasan et al [66] The lithium containing electrolyte is commonly used for lithium ion batteries and does not dissolve (FcC 2 )PbBr 3 .…”