Premium
Low‐Temperature Growth of SnO 2 Nanorod Arrays and Tunable n–p–n Sensing Response of a ZnO/SnO 2 Heterojunction for Exclusive Hydrogen Sensors
Author(s) -
Huang Hui,
Gong Hua,
Chow Chee Lap,
Guo Jun,
White Timothy John,
Tse Man Siu,
Tan Ooi Kiang
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201002115
Subject(s) - nanorod , materials science , heterojunction , selectivity , plasma enhanced chemical vapor deposition , chemical vapor deposition , hydrogen , deposition (geology) , chemical engineering , nanotechnology , optoelectronics , analytical chemistry (journal) , catalysis , paleontology , biochemistry , chemistry , organic chemistry , sediment , engineering , biology , chromatography
Uniform SnO 2 nanorod arrays have been deposited at low temperature by plasma‐enhanced chemical vapor deposition (PECVD). ZnO surface modification is used to improve the selectivity of the SnO 2 nanorod sensor to H 2 gas. The ZnO‐modified SnO 2 nanorod sensor shows a normal n‐type response to 100 ppm CO, NH 3 , and CH 4 reducing gas whereas it exhibits concentration‐dependent n–p–n transitions for its sensing response to H 2 gas. This abnormal sensing behavior can be explained by the formation of n‐ZnO/p‐Zn‐O‐Sn/n‐SnO 2 heterojunction structures. The gas sensors can be used in highly selective H 2 sensing and this study also opens up a general approach for tailoring the selectivity of gas sensors by surface modification.