Room-temperature acetaldehyde sensors built from doped and morphology-controlled ZnO thin films.
HMTA plays a dual capping role in ZnO growth, steering crystal shape between nanoprisms and nanodisks, with the nanoparticle-decorated nanoprisms giving the best acetaldehyde selectivity.
Substrate temperature controls ZnO film thickness and grain size in this zinc-nitrate-precursor study, with the thinnest, highest-resistance film giving the strongest acetaldehyde response.
Fluorine doping shrinks ZnO crystallite size and increases micro-strain, and a 4 wt% fluorine-doped film gives the strongest, most selective room-temperature acetaldehyde response.
Precursor volume alone steers spray-pyrolysis ZnO toward either better conductivity or better gas sensing, with a distinctive nanopetal morphology forming at 30 mL.
