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Study on electro-optical effects of ZnO-coated carbon nanotubes
Dissertation

Study on electro-optical effects of ZnO-coated carbon nanotubes

Hung, Chia-I
Doctor of Philosophy (PHD), 國立清華大學, 材料科學工程學系
2014

Abstract

奈米碳管 氧化鋅 原子層沈積法 光電性質 CNTs ZnO ALD Electro-optical
Abstract Carbon nanotubes (CNTs), graphene, self assembly molecular (SAM) and surface metal of framework (SurMOF) are studied and are presented in this thesis. Five chapters with three main topics are discussed and abstracts of each chapter are described as followings. Chapter 1 introduces the background of each carbon materials, including the structure, electronic properties, and chemical properties. In addition, theories of the produced, analyzed instruments and techniques employed are also discussed. Chapter 2 discusses the properties of ZnO coated aligned multi-walled CNTs. Zinc carbonates are identified at interface of CNTs and ZnO which provide the evidence of growing processes. Futuremore, Oxide coats remain optically active at ultraviolet (UV) wavelength and emissions through near-band-edge (NBE) transitions are verified by photoluminescence (PL) profiles at low and room temperature. Upon photoexcitation, fully coated tubes exhibit an increased photocurrent (Iph) and quantum efficiency. Chapter 3 demonstrates the graphene’s family, graphene nano-flakes (GNFs) used for protecting metals from electrochemical degradation. With high specific surface area comparing to graphene, GNFs play a important role as a filter to prevent the ions close to metal surfaces, which promotes resistance to corrosion. In addition, GNFs can be easily made and their flexibility shows potential as passivation layers for metals. Appendix A measures the electronic property of SAMs and a newly developed material known as SurMOFs. In the first part, the I-V diagram indicates selenium-based materials have a higher electronic conductivity than that of sulfur-based SAMs. In the second part, the resistance of SurMOFs and thickness are measured and found in direct proportion. In addition, immersing of MOFs into Fe2+-containing ferrocene solution modifies structure and greatly improves the electronic conductivity.

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