On the formation of methylammonium lead iodide perovskite thin films using a sequential close space vapor transport process
Date
2022
Authors
Journal Title
Journal ISSN
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Publisher
University of Delaware
Abstract
Methylammonium lead halide perovskites are promising materials for the next
generation of solar cells. In this document, a close space vapor transport reactor is
used to study the formation of perovskite materials for solar applications. A two-step
process is developed, consisting of the deposition of a lead iodide thin film and a
subsequent reaction with methylammonium iodide vapor. Each process is investigated
experimentally and modeled mathematically to provide a foundation for the design of a
scaled-up vapor transport deposition process. The mass transport regime is determined
to obey the laws of diffusion, and the growth characteristics of the lead iodide thin film
are characterized as a function of temperature and pressure. The methylammonium
iodide reaction mechanism is found to proceed through a non-catalytic, heterogeneous,
vapor-solid reaction, and the kinetics are well-described by a sharp-interface model.
The viability of alloying the methylammonium lead iodide perovskite material with
formamidinium through a multi-stage vapor-solid reaction is explored. The limitations
of the close space vapor transport system are identified, and suggestions for the design
of a scaled-up vapor transport deposition process are provided.
Description
Keywords
Deposition, Perovskite, Reaction, Thin film