Hexagonal boron nitride coated carbon nanotubes：interlayer polarization improved field emission
博士 === 國立清華大學 === 材料科學工程學系 === 103 === Carbon nanotubes (CNTs) which have high mechanical strength, chemical stability, aspect ratio, and field enhancement factor (β) are considered as ideal field emitters. In this thesis, coating of h-BN onto carbon nanotubes induces polarization at interfaces and...
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| Format: | Others |
| Language: | en_US |
| Published: |
2015
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| Online Access: | http://ndltd.ncl.edu.tw/handle/67098999844193229908 |
| Summary: | 博士 === 國立清華大學 === 材料科學工程學系 === 103 === Carbon nanotubes (CNTs) which have high mechanical strength, chemical stability, aspect ratio, and field enhancement factor (β) are considered as ideal field emitters. In this thesis, coating of h-BN onto carbon nanotubes induces polarization at interfaces and charges become localized at N and C atoms respectively. Field emission of coated tubes is found to be highly stable and current density fluctuates within 4%. Study further reveals that electric field established between coatings and tubes facilitates charge transfer across interfaces and electrons are emitted through occupied and unoccupied bands of N and B atoms. Measurements give turn on field = 6.51 V/μm for CNTs and 2.65-2.67 V/μm for coated tubes; the threshold field being measured to be 9.82 V/μm and 4.41-4.43 V/μm respectively.
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