Surface defects on ZnO nanowires: implications for design of sensors.

摘要: Surface defects are commonly believed to be fundamentally important gas-sensor performance. We examine the effect of gas coverage and ethanol orientation on its adsorption stoichiometric oxygen deficient (101(-)0) nanowire surface. Our density functional theory calculations show that adsorbs in multiple stable configurations at coverages between 1/4 1 ML, highlighting ability ZnO detect ethanol. Ethanol prefers bind a surface Zn via adsorbate atom and, if is close proximity, molecule further stabilized by formation hydrogen bond hydroxyl group oxygen. Two primary were identified have different binding strengths could distinguished experimentally magnitude their OH stretching frequency. findings adsorbed ZnO(101(-)0) has reduced strength. This due either lack (due deficiency oxygen) or reconstruction occurs defect weakens interaction. contrast enhanced interaction for other gases. Despite this difference, still acts as reducing gas, donating electrons decreasing band gap. molecules prefer orientated parallel each facilitate bonding defect-free