Publications on chemiresistive and semiconductor gas sensors, mostly built from doped or nanostructured ZnO thin films, targeting ammonia, ethanol, acetaldehyde, xylene, and other vapors at room temperature. Each entry covers how the sensing film was made, what it detects, and how sensitive and selective it is.
Annealing transforms a zinc-dominant spray-deposited film into polycrystalline ZnO, and only the film annealed at 623 K gives a useful room-temperature ethanol response.
Optimized spray pyrolysis conditions grow c-axis oriented boron-doped ZnO films instead of the usual crystallinity loss, with 10 mol% boron giving the strongest, most selective room-temperature ammonia response.
Cobalt doping shifts a spray-pyrolysis ZnO film's gas selectivity between acetaldehyde and ethanol depending on doping level, without changing its 19-25 nm crystallite size range.
A single-step electrospinning route grows ZnO nanorods with three distinct tip shapes, and the flat-ended, loosely packed nanorods give the strongest room-temperature ethanol response.
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.
ZnO nanospheres and nanorods made by chemical-free laser ablation in water both show clear room-temperature selectivity for ethanol, detectable down to 50 ppm.
Magnesium doping tunes spray-pyrolysis ZnO crystallite size and band gap, with the lowest-doping film reaching a room-temperature ammonia response of 796 at 100 ppm.
Manganese doping shrinks ZnO crystallite size from 28 to 7 nm while keeping films selective to ammonia, with the best-performing film giving roughly 5x the undoped response and 60-day stability.
A review of the redox chemistry behind metal-oxide gas sensing compares n-type (ZnO, SnO2, In2O3, WO3) and p-type (CuO, NiO) oxides across humidity, grain size, and dopant effects on sensitivity.
Nickel doping narrows the optical band gap of spray-deposited ZnO thin films, and a 0.008 M nickel-doped film gives the strongest room-temperature ethanol response, responding in about 50 seconds.
