| 1. |
- Nguyen, Hugo, 1955-, et al.
(författare)
-
Controllable growth of ZnO nanowires grown on discrete islands of Au catalyst for realization of planar-type micro gas sensors
- 2014
-
Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 193, s. 888-894
-
Tidskriftsartikel (refereegranskat)abstract
- The proper engineering design of gas sensors and the controlled synthesis of sensing materials for the high-performance detection of toxic gas are very important in the fabrication of handheld devices. In this study, an effective design for gas sensor chips is developed to control the formation of grown ZnO nanowires (NWs).The design utilizes the dendrite islands of Au catalyst deposited on and between Pt electrodes of a planar-type micro gas sensor so that NWs can grow on instead of a continuous Au seed layer. This method results in an increase of NW-NW junctions on the device and also eliminates current leakage through the seed layer, which results in a higher sensitivity. The results show that the developed gas-sensing devices could be used to monitor NO2 at moderate temperature (~250 °C) and/or ethanol at a high temperature (~400 °C).
|
|
| 2. |
- Tan, Ha Minh, 1989-, et al.
(författare)
-
Self-heating Effect on Tin Oxide Nanowire Network Gas Sensor
- 2014
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Self-heated gas sensors have attracted much of interests owing to the ultra-low power consumption as well as simple device fabrication. However, it still requires further improvement to overcome some technical difficulties such as high operation voltage, long-term stability, and mass production. In this work, we propose a nanowire nework structure to solve these problems. The self-heating effect on fabricated structures was tested and working temperature was evaluated by base resistance measurement and infrared emission microscopy methods. The fabricated sensor consumed an electric power of about 40 mW to reach the working temperature up to 250 oC. The NO2 sensing properties were initially studied on this sensor structure.
|
|
| 3. |
-
A design of high performance gas sensor array withdiscrete islands of Au catalyst for increasing of ZnO nanowire junctions
- 2013
-
Proceedings (redaktörskap) (refereegranskat)abstract
- In this study, an effective design for growth of ZnO nanowires directly on gas sensor chips is introduced. The design utilizes the dendrite islands of Au catalyst deposited between and on the Pt electrodes for the nanowires to grow on instead of a continuous seed layer or Au film. This lead to an increase of the nanowirenanowire junctions in the devices, as well as a reduction of the leak current that would occur through the mentioned alternative seed layer; resulting in a higher sensitivity. The results showed that the developed gas sensors could be used for monitoring of NO2 at low concentration.
|
|
| 4. |
- Han, Hoang Van, et al.
(författare)
-
Single-crystal zinc oxide nanorods with nanovoids as highly sensitive NO2 nanosensors
- 2013
-
Ingår i: Materials letters (General ed.). - : Elsevier BV. - 0167-577X .- 1873-4979. ; 94, s. 41-43
-
Tidskriftsartikel (refereegranskat)abstract
- Design and synthesis of nanostructured materials with a highly porous crystal structure and high specific surface area are the key issues to an enhanced gas sensing performance. This letter introduces a simple and scalable hydrothermal method to fabricate single-crystal ZnO nanorods (NRs) with nanovoids (NVs) for highly sensitive NO2 nanosensors. The fabricated ZnO NRs have a single-crystal structure with an average length and diameter of about 900 nm and 23 nm, respectively. NVs of less than 5 nm size are found frequently along the NRs. Gas-sensing characterizations revealed that the ZnO NR sensors exhibited a relatively high response to sub-ppm NO2 with excellent stability after 8 cycles of switching from NO2 to dry air without significant response reduction.
|
|
