Enhancement of field electron emission properties of carbon nanotubes zinc oxide nanocomposites using single and multi step methods (IR)
This study aimed to enhance the field electron emission (FEE) properties of carbon nanotubes (CNTs) synthesized from waste cooking palm oil combined with zinc oxide (ZnO) to produce CNTs/ZnO nanocomposites. The methods used in this study were single and multi-step depositions. The single-step deposi...
Saved in:
| Main Author: | |
|---|---|
| Format: | thesis |
| Language: | eng |
| Published: |
2015
|
| Subjects: | |
| Online Access: | https://ir.upsi.edu.my/detailsg.php?det=1651 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | This study aimed to enhance the field electron emission (FEE) properties of carbon nanotubes (CNTs) synthesized from waste cooking palm oil combined with zinc oxide (ZnO) to produce CNTs/ZnO nanocomposites. The methods used in this study were single and multi-step depositions. The single-step deposition method was done by directly mixing the CNTs and ZnO precursors and they were synthesized using thermal chemical vapor deposition (TCVD) method for 30 minutes. Meanwhile, the multi-step deposition process was carried out by combining TCVD and sol-gel immersion methods to fabricate CNTs/ZnO nanocomposites. There were three different ZnO nanostructures namely nanorods, nanoflowers and nanorods-nanoflakes which were composited with CNTs via multi-step deposition process. The obtained samples were analyzed using electron microscopy, energy dispersive X-ray, micro- Raman spectroscopy, X-ray diffraction spectroscopy, photoluminescence spectroscopy and four-point probe current-voltage measurement. The field emission properties of the samples were also studied using FEE measurement. The findings showed that the turn-on and threshold fields of CNTs/ZnO nanocomposites decreased as compared to pristine CNTs. Other than that, different nanostructures of ZnO contributed to the FEE performance of CNTs/ZnO nanocomposites. The best FEE properties were given by the growth of CNTs on ZnO nanoflowers, which has the lowest turn-on field of 0.8 V/?m at current density of 1 ?A/cm2 and a high field enhancement factor of 9417. Larger emission site density and lower screening effect in this sample were believed to affect the FEE performance. As a conclusion, the fabrication of CNTs/ZnO nanocomposites have successfully enhanced the FEE properties of CNTs. Implication of this study is that it provide a new insight on advancing the synthesis of CNTs/ZnO nanocomposites for electron emission devices. |
|---|