Comparison of SnBr4 and di‐n‐butyl tin diacetate as laser‐assisted chemical vapor deposition precursors for SnO2‐based gas sensors

Abstract

Laser-assisted chemical vapor deposition (LCVD) was utilized to produce SnO 2 films from SnBr 4 plus air, O 2 or N 2 O. SnO 2 films were successfully generated using either 222 or 308 nm laser pulses but there was evidence for film contamination when using less than 60 mJ/ pulse laser energies at 222 nm. Films were characterized using ultraviolet absorption spectroscopy; the spectra of films with impurities resembled the spectrum of SnBr 4 . AFM images were obtained which indicated that this LCVD route produced small and fairly uniform SnO 2 grains which were 50-100 nm in size. Multiphoton ionization spectroscopy was used to verify that the dissociation of a film dopant precursor, copper(II) acetate, produced gasphase copper atoms under conditions similar to those used in film deposition experiments. The deposition of SnO 2 from SnBr 4 plus an oxidant was found to be more efficient than from di-nbutyl tin diacetate but films produced via this new LCVD route, including those doped with copper, were found to be much less sensitive in preliminary gas-sensing screening.

Synthesis of Tin Oxide Nanocrystalline Phases via Use of Tin(II) Halide Precursors

“…Along with thermal oxidation of physical-vapor-deposited atomic tin films, other reported methods for varying the stoichiometry of tin oxide materials include use of Sn(IV) and Sn(II) precursors in organometallic chemical vapor deposition, as well as oxidation of the surface of thin films initially prepared by pulsed laser deposition . Previous work in our laboratory , has utilized laser-assisted chemical vapor deposition (LCVD) to produce SnO 2 and doped SnO 2 films. Preliminary experiments indicate that the LCVD technique can also be adapted to generate films containing polycrystalline SnO from Sn(IV) precursors.…”

Morphological engineering of $$\hbox {SnO}_{2}$$ and $$\hbox {In}_{2}\hbox {O}_{3}$$ films deposited by spray pyrolysis

“…This task is very important, since the electrophysical and surface properties of polycrystalline metal oxide films as well as the parameters of devices based on these materials depend strongly on the morphology of the films, described by parameters such as the size and the shape of grains and crystallites, film texturing, surface roughness and porosity [1]. It has been found that these structural parameters of the films can be controlled by selecting an appropriate substrate, deposition temperature, properties of the precursors, doping elements, film thickness or deposition method [1][2][3][4][5][6]. However, these approaches optimizing the morphology of the film have significant limitations on the possible change in the film structure that can be obtained.…”

Synthesis and Characterization of Lipophilic Organotins. Application to the Functionalization of Silica Gel

“…Volatile organotins have been mainly used in material science to process doped or undoped tin dioxide thin films by pyrosol deposition, spray pyrolysis, and chemical vapor deposition, or to prepare under vacuum silica- or alumina-supported tin species . However, few research efforts focused on the preparation of functional materials from organotin precursors by low-temperature solution routes, for instance to obtain stable hybrid materials in which both organic and inorganic components are tightly associated through covalent bonds .…”