Structure–Property–Function Relationships in Nanoscale Oxide Sensors: A Case Study Based on Zinc Oxide

Abstract

Chemical sensing on oxide sensors is a complex phenomenon involving catalytic activity as well as electronic properties. Thus, the properties of oxide sensors are highly sensitive towards structural changes. Effects like surface area, grain size, and, in addition, the occurrence of defects give separate contributions to the current. Structure–property–function relationships can be elucidated using a combination of state‐of‐the‐art analytical techniques. It is shown, that impurity atoms in the oxide lattice influence the performance of ZnO sensors more strongly than the other factors.

Gas sensing properties of <i>c</i>-axis-oriented Al-incorporated ZnO films epitaxially grown on (11-20) sapphire substrates using pulsed laser deposition

“…7), 8) In recent years, nanostructured ZnO has been synthesized, and improvements in gas sensing performance have been reported. 9)11) The gas sensing mechanism of ZnO is of the surface-controlled type.…”

Low‐Temperature Growth of SnO2 Nanorod Arrays and Tunable n–p–n Sensing Response of a ZnO/SnO2 Heterojunction for Exclusive Hydrogen Sensors

“…[ 24 ] Numerous challenges remain unsolved and exclusive H 2 sensors are still highly required. [ 25 ] As for the use of other oxides, ZnO in itself is an excellent sensing material, [ 26,27 ] and it has also been used as additive to improve the sensitivity and selectivity of SnO 2 sensors to ethanol [ 28 ] and H 2 S gas, [ 29 ] NO 2 , [ 30 ] and CO. [ 31 ] An enhancement was observed, which was attributed to the ZnOSnO 2 interface, [ 32 ] but the mechanism is still unclear. [ 30 ] In this study, uniform SnO 2 nanorod arrays have been deposited by plasma-enhanced chemical vapor deposition (PECVD) and highly selectively H 2 sensors have been fabricated by surface modifi cation of the SnO 2 nanorod arrays using ZnO.…”

Nanostructured ZnO chemical gas sensors

“…Their specific physical and chemical properties opened great perspectives for their applications in environmental monitoring and catalysis [1][2][3][4][5][6]. Among different transition oxides, ZnO, endowed of a wide direct band gap (3.37 eV) high exciton energy (60 meV), is one of the most studied materials due to its mixed covalent/ionic chemical bonds [7].…”