Prominent Reducing Gas-Sensing Performances of <i>n</i>-SnO₂ Nanowires by Local Creation of <i>p</i>&#x2013;<i>n</i> Heterojunctions by Functionalization with <i>p</i>-Cr₂O₃ Nanoparticles

다국어 초록 (Multilingual Abstract)

<P>A novel approach to improving the reducing gas-sensing properties of <I>n</I>-type nanowires (NWs), by locally creating <I>p</I>–<I>n</I> heterojunctions with <I>p</I>-type nanoparticles (NPs), is proposed. As a model system, this work investigates the sensing behaviors of <I>n</I>-SnO<SUB>2</SUB> NWs functionalized with <I>p</I>-Cr<SUB>2</SUB>O<SUB>3</SUB> NPs. Herein, <I>n</I>-SnO<SUB>2</SUB> NWs demonstrate greatly improved reducing gas-sensing performance when functionalized with <I>p</I>-Cr<SUB>2</SUB>O<SUB>3</SUB> NPs. Conversely, such functionalization deteriorates the oxidizing gas-sensing properties of <I>n</I>-SnO<SUB>2</SUB> NWs. These phenomena are closely related to the local suppression of the conduction channel of <I>n</I>-type NWs, in the radial direction, beneath the <I>p</I>–<I>n</I> heterojunction by the flow of charge carriers. The approach used in this work can be used to fabricate sensitive reducing-gas sensors based on <I>n</I>-type NWs.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-20/am504164j/production/images/medium/am-2014-04164j_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am504164j'>ACS Electronic Supporting Info</A></P>