Reaction Dynamics of C(NH₂)₃SnI₃ Formation from Vacuum-Deposited C(NH₂)₃I and SnI₂ Bilayer Thin Films Investigated by In Situ Infrared Multiple-Angle Incidence-Resolved Spectroscopy

Abstract

Understanding the formation process of organic–inorganic halide perovskite (OIHP) thin films is important for the fabrication of high-quality thin films, which, in turn, are crucial for achieving high-performance devices. To address this challenge, we developed an in situ system of infrared multiple-angle incidence-resolved spectroscopy (IR-MAIRS) combined with a vacuum deposition system. “Orientation-free” isotropic spectra constructed from IR-MAIRS spectra enable us to perform quantitative analysis of the formation process of C­(NH2)3SnI3 (GASnI3) thin films from unreacted C­(NH2)3I (guanidine hydroiodide (GAI))/SnI2 bilayer structures predeposited in a vacuum. The analysis of the dependence of the GASnI3 formation rate on the reaction temperature using the Avrami model has revealed that a diffusion-controlled reaction process of GAI and SnI2 governs the formation kinetics. The present study points to the usefulness of in situ IR-MAIRS analysis in understanding the growth mechanisms of vacuum-deposited OIHP thin films and hence the potential to accelerate the development of vacuum processes for the fabrication of high-quality OIHP thin films.

Multiple-angle incidence resolution spectrometry: applications in nanoarchitectonics and applied physics

“…Therefore, from the intensity of the OI spectrum, the quantitative changes of chemical species associated with chemical reactions can be analyzed in the thin film. 106,[134][135][136] This further makes it possible to estimate thermodynamic constants such as rate constants and activation energies. 135) In the following, we will introduce examples of studies in which the pMAIRS technique is applied to the analysis of on-surface reactions.…”

“…106,[134][135][136] This further makes it possible to estimate thermodynamic constants such as rate constants and activation energies. 135) In the following, we will introduce examples of studies in which the pMAIRS technique is applied to the analysis of on-surface reactions.…”

“…8(a)]. 135) To incorporate the MAIRS technology into a vacuum chamber, MAIRS2 is fairly suitable because the angle of incidence is fixed in MAIRS2. In this study, C(NH 2 ) 3 I (guanidine hydroiodide: GAI) and SnI 2 were used as organic and inorganic sources, respectively.…”

Quantitative Analysis of Photochemical Reactions in Pentacene Precursor Films

“…In addition, an optically isotropic (OI) spectrum, which is a molecular-orientation free spectrum, is also obtained by simply averaging the IP and OP spectra . Since the band intensity of the OI spectrum is proportional only to the quantity of chemical species, the quantitative analysis of chemical reactions can be accurately performed. ,, IR spectroscopy has another powerful benefit for detecting trace molecules irrespective of the crystallinity, , such as impurities, including residual solvents.…”