TY - JOUR
T1 - Electrochemical and Thermal Etching of Indium Tin Oxide by Solid-State Hybrid Organic-Inorganic Perovskites
AU - Kerner, Ross A.
AU - Rand, Barry P.
N1 - Funding Information:
This work was supported by the ONR Young Investigator Program (Award #N00014-17-1-2005). The authors acknowledge the use of Princeton’s Imaging and Analysis Center, which is partially supported by the Princeton Center for Complex Materials, a National Science Foundation (NSF)-MRSEC program (DMR-1420541).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/8/26
Y1 - 2019/8/26
N2 - We show that tin-doped indium oxide (ITO) can be thermally etched by the Brønsted acid salts methylammonium iodide (MAI), methylammonium lead triiodide (MAPbI3), and formamidinium lead triiodide (FAPbI3) in solid-state films and devices at common processing temperatures. More importantly, a series of reactions within an ITO/hybrid perovskite/Au device can be electrochemically induced near room temperature by applied cathodic voltages as low as -1.2 V. Cyclic voltammetry in this range leads to eventual In3+ leaching into the perovskite layer in the form of InI3, unambiguously identified by a binding energy signature of 445.9-446.3 eV measured by X-ray photoelectron spectroscopy. Furthermore, the etching is exacerbated by defects generated by O2-plasma treatment of the ITO compared to UV-ozone cleaning, lowering the reaction potential and the electrochemical stability window of an ITO/MAPbI3/Au device. Low-temperature, electrochemical reactivity at this interface has implications on operational stability, fundamental studies of hybrid perovskite materials, electron (or hole) transport layer free perovskite devices, reverse bias degradation, and other applications where ITO/hybrid perovskite contact is possible.
AB - We show that tin-doped indium oxide (ITO) can be thermally etched by the Brønsted acid salts methylammonium iodide (MAI), methylammonium lead triiodide (MAPbI3), and formamidinium lead triiodide (FAPbI3) in solid-state films and devices at common processing temperatures. More importantly, a series of reactions within an ITO/hybrid perovskite/Au device can be electrochemically induced near room temperature by applied cathodic voltages as low as -1.2 V. Cyclic voltammetry in this range leads to eventual In3+ leaching into the perovskite layer in the form of InI3, unambiguously identified by a binding energy signature of 445.9-446.3 eV measured by X-ray photoelectron spectroscopy. Furthermore, the etching is exacerbated by defects generated by O2-plasma treatment of the ITO compared to UV-ozone cleaning, lowering the reaction potential and the electrochemical stability window of an ITO/MAPbI3/Au device. Low-temperature, electrochemical reactivity at this interface has implications on operational stability, fundamental studies of hybrid perovskite materials, electron (or hole) transport layer free perovskite devices, reverse bias degradation, and other applications where ITO/hybrid perovskite contact is possible.
KW - halide perovskites
KW - interface reactivity
KW - metal oxides
KW - photoelectron spectroscopy
KW - solid-state electrochemistry
KW - stability window
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U2 - 10.1021/acsaem.9b01356
DO - 10.1021/acsaem.9b01356
M3 - Article
AN - SCOPUS:85070800115
SN - 2574-0962
VL - 2
SP - 6097
EP - 6101
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
IS - 8
ER -