by Poon Chun Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 110-112). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.2 / ABSTRACT --- p.3 / TABLE OF CONTENTS --- p.5 / LIST OF FIGURES --- p.8 / LIST OF TABLES --- p.13 / Chapter CHAPTER 1 --- INTRODUCTION --- p.14 / Chapter 1.1 --- Overview --- p.14 / Chapter 1.2 --- Ferromagnetism --- p.15 / Chapter 1.3 --- Ferromagnetic granular thin film --- p.16 / Chapter 1.4 --- Ferromagnetism-magnetization --- p.17 / Chapter 1.5 --- Ferromagnetism - magnetization of a polycrystalline --- p.18 / Chapter 1.6 --- Soft and hard magnetic materials --- p.21 / Chapter 1.7 --- Preparation methods --- p.22 / Chapter 1.8 --- This thesis --- p.24 / Chapter CHAPTER 2 --- SAMPLE PREPARATION AND EXPERIMENTAL METHODS --- p.25 / Chapter 2.1 --- Sample preparation --- p.25 / Chapter 2.1.1 --- The pulsed filtered cathodic arc co-deposition system --- p.25 / Chapter 2.1.2 --- Details of sample preparation --- p.27 / Chapter 2.1.3 --- Improvement of the target holder --- p.30 / Chapter 2.2 --- Rutherford backscattering spectrometry (RBS) --- p.30 / Chapter 2.3 --- X-ray diffraction (XRD) --- p.32 / Chapter 2.3.1 --- Diffraction technique --- p.32 / Chapter 2.3.2 --- Scherrer's formula --- p.35 / Chapter 2.4 --- Raman spectroscopy --- p.35 / Chapter 2.5 --- Transmission electron microscopy (TEM) --- p.36 / Chapter 3.5.1 --- The technique of transmission electron microscopy (TEM) --- p.36 / Chapter 3.5.2 --- Transmission electron microscopy (TEM) sample preparation --- p.37 / Chapter 2.6 --- X-ray photoelectron spectroscopy (XPS) --- p.41 / Chapter 2.6.1 --- The principle of XPS --- p.41 / Chapter 2.6.2 --- Qualitative analysis of XPS (chemical shift) --- p.43 / Chapter 2.7 --- Scanning probe microscopy (SPM) --- p.43 / Chapter 2.7.1 --- The principle of atomic force microscopy (AFM) --- p.43 / Chapter 2.7.2 --- Tapping mode atomic force microscopy --- p.44 / Chapter 2.7.3 --- Magnetic force microscopy (MFM) --- p.46 / Chapter 2.8 --- Vibrating sample magnetometer (VSM) --- p.47 / Chapter 2.8.1 --- The principle of VSM operation --- p.47 / Chapter 2.8.2 --- Useful of the pick up coils --- p.49 / Chapter 2.8.3 --- M-H Loop --- p.50 / Chapter 2.9 --- Four-contacts technique --- p.51 / Chapter CHAPTER 3 --- CHARACTERIZATION OF CO-DEPOSITED CO-C SAMPLES --- p.53 / Chapter 3.1 --- Introduction --- p.53 / Chapter 3.2 --- Results and discussion --- p.54 / Chapter 3.2.1 --- NRBS measurements --- p.54 / Chapter 3.2.2 --- X-ray diffraction --- p.57 / Chapter 3.2.3 --- Raman spectroscopy --- p.59 / Chapter 3.2.4 --- AFM and MFM measurements --- p.64 / Chapter 3.2.4.1 --- AFM result --- p.64 / Chapter 3.2.4.2 --- MFM result --- p.68 / Chapter 3.2.5 --- Vibrating sample magnetometer (VSM) measurements --- p.73 / Chapter 3.3 --- Summary --- p.78 / Chapter CHAPTER 4 --- CHARACTERIZATION OF CO-DEPOSITED FE-C SAMPLES --- p.79 / Chapter 4.1 --- Introduction --- p.79 / Chapter 4.2 --- Results and discussion --- p.80 / Chapter 4.2.1 --- NRBS measurement --- p.80 / Chapter 4.2.2 --- X-ray diffraction --- p.81 / Chapter 4.2.3 --- x-ray photoelectron spectroscopy (XPS) --- p.84 / Chapter 4.2.4 --- AFM results --- p.87 / Chapter 4.2.5 --- MFM results --- p.91 / Chapter 4.2.6 --- Vibrating sample magnetometer (VSM) measurements --- p.95 / Chapter 4.2.7 --- Resistivity --- p.99 / Chapter 4.2.8 --- Transmission electron microscopy (TEM) --- p.100 / Chapter 4.3 --- Application potential --- p.101 / Chapter 4.4 --- Summary --- p.104 / Chapter CHAPTER 5 --- CONCLUSION --- p.106 / Chapter 5.1 --- Main results of this work --- p.106 / Chapter 5.2 --- Future work --- p.108 / REFERENCE --- p.110 / PUBLICATIONS --- p.112 / APPENDIX --- p.113

by Lee Koon Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Lee Koon Ho. / Acknowledgements --- p.i / Abstract --- p.ii / 論文摘要 --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.ix / Chapter Chapter I --- Introduction / Chapter 1.1 --- Review of magnetoresistance --- p.1 -1 / Chapter 1.1.1 --- Colossal magnetoresistance in rare earth manganites --- p.1 -2 / Chapter 1.1.2 --- Review of manganite multilayer system --- p.1-10 / Chapter 1.2 --- Research motivation --- p.1-12 / Chapter 1.2.1 --- Scope of the thesis --- p.1-14 / Reference --- p.1-15 / Chapter Chapter II --- Instrumentation --- p.2-1 / Chapter 2.1 --- Facing target sputtering system --- p.2-1 / Chapter 2.1.1 --- Preparation of LCMO/PCMO multilayer thin film --- p.2-3 / Chapter 2.2 --- Annealing system --- p.2-5 / Chapter 2.2.1 --- Oxygen post-annealing system --- p.2-5 / Chapter 2.2.2 --- Vacuum annealing system --- p.2-7 / Chapter 2.3 --- X-ray diffraction (XRD) --- p.2-9 / Reference --- p.2-11 / Chapter Chapter III --- Annealing of LCMO/PCMO multilayer thin films --- p.3-1 / Chapter 3.1 --- Oxygen post-annealing of LCMO/PCMO multilayer thin film --- p.3-1 / Chapter 3.1.1 --- Introduction to post-annealing of managanites oxides --- p.3-1 / Chapter 3.1.2 --- LCMO and PCMO Single Layer Films Description --- p.3-1 / Chapter 3.1.3 --- Selection of PCMO --- p.3-5 / Chapter 3.1.4 --- La2/3Ca1/3MnO3/ Pr2/3Ca1/3MnO3 Multilayer Description --- p.3-5 / Chapter 3.1.5 --- Oxygen post-annealing condition --- p.3-9 / Chapter 3.1.6 --- Oxygen post annealing of P100 --- p.3-9 / Chapter 3.1.7 --- Conclusion --- p.3-16 / Chapter 3.2 --- Vacuum annealing of LCMO/PCMO multilayer thin films --- p.3-19 / Chapter 3.2.1 --- Introduction --- p.3-19 / Chapter 3.2.2 --- Sample description --- p.3-20 / Chapter 3.2.3 --- Vacuum annealing condition --- p.3-21 / Chapter 3.2.4 --- Vacuum Annealing of LCMO and PCMO --- p.3-23 / Chapter 3.2.5 --- Vacuum Annealing of LCMO/PCMO multilayer thin films --- p.3-29 / Chapter 3.2.6 --- Conclusion --- p.3-49 / References --- p.3-50 / Chapter Chapter IV --- Activation energy of small polaron in LCMO/PCMO multilayer thin films --- p.4-1 / Chapter 4.1 --- Introduction to small lattice polarons --- p.4-1 / Chapter 4.2 --- Theory of small polarons --- p.4-2 / Chapter 4.3 --- Activation energy of small polaron --- p.4-3 / Chapter 4.4 --- Discussion --- p.4-7 / References --- p.4-8 / Chapter Chapter V --- Conclusions --- p.5-1

Throughout this work several thin film resists have been studied with substantial focus on HafSOx and SU-8. The study of HafSOx has granted more insight into how inorganic, spin coated films form and react under the electron beam. These films have been shown to form a thin dense crust at the surface that could have interesting implications in the interaction of the electrons. Continuing to further understand the electron interactions within the resist, low voltage patterns were created allowing the accelerating voltage to be matched to the film. With this general knowledge, higher resolution films can be constructed with shorter patterning times. Both resists complement each other in that HafSOx produces incredibly thin, dense structures to be formed with features below 10 nm in all dimensions. SU-8 allows micron thick features to be created over several millimeters. This flexibility in feature size enabled the creation of large fractals that could improve neuron binding to artificial retina down to the smallest fractals reported that are interesting for their applications as antennas. The final facet of this work involved looking at other methods of making structures. This was done through adding differing salts to organic molecules that stack into unique crystals. This dissertation includes previously published co-authored material.

We present a theoretical analysis of surface-plasmon-mediated mode-coupling in a planar thin film metal/insulator stack. The spatial overlap of a surface plasmon polariton (SPP) and a waveguide mode results in a Fano interference analog. Tuning of the material parameters effects the modes and output fields of the system. Lastly, the intensity and phase sensitivity of the system are compared to a standard surface plasmon resonance (SPR). We begin with background information on Fano interference, an interference effect between two indistinguishable pathways. Originally described for autoionization, we discuss the analogs in other systems. We discuss the features of Fano interference in the mode diagrams, and the Fano resonance observed in the output field. The idea of a geometric Fano resonance (GFR) occurring in the angular domain is presented. Background information on surface plasmon polaritons is covered next. The dielectric properties of metals and how they relate to surface plasmons is first reviewed. The theoretical background of SPPs on an infinite planar surface is covered. The modes of a two planar interface metal/insulator stack are reviewed and the leaky properties of the waveguide are shown in the reflectance. We solve for modes of a three interface metal/insulator stack and shows an avoided crossing in the modes indicative of Fano interference. We observe the asymmetric Fano resonance in the angular domain in the reflectance. The tunability of the material parameters tunes the GFR of the system. The GFR tuning is explored and different Fano lineshapes are observed. We also observe a reversal of the asymmetry Fano lineshape, attributed to the relate phase interactions of the non-interacting modes. The phase of the GFR is calculated and discussed for the variations of the parameters. The reflected field is explored as the insulator permittivities are varied. As the waveguide permittivity is varied, we show there is little response from the system. As the exterior permittivity is varied, the reflectance exhibits the geometric Fano resonance and the tunability of the lineshape is explored. Finally, we calculate the sensitivities of our metal/insulator stack to changes in the permittivity and compare them to the sensitivities of SPRs.

Lai Chung Wing = 金屬膜覆蓋在氧化鋅上之光學變化 / 黎頌榮. / Thesis submitted in: July 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Lai Chung Wing = Jin shu mo fu gai zai yang hua xin shang zhi guang xue bian hua / Li Songrong. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of contents --- p.iv / List of Figures --- p.vi / Chapter Chapter 1 --- Introduction / Chapter 1.1. --- Motivation --- p.1-1 / Chapter 1.2. --- Literature Review --- p.1-2 / Chapter 1.3. --- Our Study --- p.1-4 / References --- p.1-6 / Chapter Chapter 2 --- Methodology and Experiments / Chapter 2.1. --- RF sputtering --- p.2-1 / Chapter 2.1.1. --- Setup of RF sputtering --- p.2-2 / Chapter 2.1.2. --- Sample preparation --- p.2-3 / Chapter 2.2. --- Scanning electron Microscope --- p.2-4 / Chapter 2.3. --- Cathodoluminescence --- p.2-5 / Chapter 2.3.1. --- Background of CL --- p.2-6 / Chapter 2.3.2. --- Room temperature CL studies --- p.2-7 / Chapter 2.3.3. --- Software: Casino --- p.2-8 / Chapter 2.3.4. --- Depth resolved CL studies --- p.2-10 / Chapter 2.3.5. --- Power dependent CL studies --- p.2-11 / Chapter 2.4. --- Photoluminescence / Chapter 2.4.1. --- General background of PL --- p.2-11 / Chapter 2.4.2. --- Room temperature PL studies --- p.2-12 / Chapter 2.4.3. --- Quantum efficiency measurement --- p.2-13 / Chapter 2.5. --- Optical transmission measurement --- p.2-13 / References --- p.2-15 / Chapter Chapter 3 --- Experimental Results and Data Analysis / Chapter 3.1. --- Study of Optical emissions of bare and Au-capped ZnO --- p.3-1 / Chapter 3.1.1. --- RT-luminescence of ZnO --- p.3-1 / Chapter 3.1.2. --- RT- Luminescence of Au- capped ZnO films --- p.3-2 / Chapter 3.2. --- RT-luminescence of metal capped ZnO --- p.3-7 / Chapter 3.3. --- Power dependent and depth Resolved CL --- p.3-10 / Chapter 3.3.1. --- Dependence of the CL on beam energy --- p.3-10 / Chapter 3.3.2. --- Dependence of the CL intensity on beam energy --- p.3-13 / Chapter 3.4. --- Dependence of metal thickness on the RT- luminescence --- p.3-17 / References --- p.3-19 / Chapter Chapter 4 --- Discussions / Chapter 4.1. --- General discussions --- p.4-1 / Chapter 4.2. --- Surface recombination Velocity / Chapter 4.2.1. --- Quantum Efficiency --- p.4-2 / Chapter 4.2.2. --- Simulation of the dependence of surface recombination velocity on the CL intensity of ZnO --- p.4-5 / Chapter 4.3. --- Effects of metallization on MgZnO/ZnO bilayer --- p.4-10 / Chapter 4.4. --- Surface plasmon --- p.4-13 / Chapter 4.5. --- PL measurement from the backside of substrate --- p.4-18 / Chapter 4.5.1. --- Au and Ag coating by sputtering --- p.4-19 / Chapter 4.5.2. --- Au and Ag coating by thermal evaporation --- p.4-21 / Chapter 4.6. --- Au coating spaced by MgO --- p.4-23 / Chapter 4.7. --- Optical transmission of Au-capped ZnO --- p.4-25 / Chapter 4.8. --- Cross Section images by AFM and TEM --- p.4-27 / Chapter 4.9. --- Application: optical improvement of semiconductor --- p.4-30 / Chapter 4.10. --- Summary --- p.4-32 / References --- p.4-34 / Chapter Chapter 5 --- Conclusions --- p.5-1 / Appendix I --- p.A / Appendix II --- p.K

Chong Yuen Tung = 硅化鐵薄膜的相和微觀結構 / 莊宛曈. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 63-65). / Text in English; abstracts in English and Chinese. / Chong Yuen Tung = Gui hua tie bo mo de xiang he wei guan jie gou / Zhuang Wantong. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgment --- p.iii / Table of contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.x / Chapter CHAPTER 1: --- Introduction --- p.1 / Chapter CHAPTER 2: --- Background --- p.4 / Chapter 2.1 --- Phases of crystalline FeSi2 --- p.4 / Chapter 2.2 --- Electronic structure of β-FeSi2 --- p.7 / Chapter 2.3 --- Orientation relationship between β-FeSi2 and Si --- p.8 / Chapter CHAPTER 3: --- Instrumentation --- p.10 / Chapter 3.1 --- Metal vapor vacuum arc ion source implantation --- p.10 / Chapter 3.2 --- Rutherford backscattering --- p.12 / Chapter 3.3 --- Transmission Electron Microscopy (TEM) --- p.13 / Chapter 3.3.1 --- Principles of TEM --- p.13 / Chapter 3.3.2 --- Electron specimen interaction and contrast --- p.14 / Chapter 3.3.3 --- Electron Diffraction --- p.15 / Chapter 3.3.4 --- Sample Preparation --- p.17 / Chapter 3.3.4.1 --- Plan-view sample --- p.17 / Chapter 3.3.4.2 --- Cross-section sample --- p.17 / Chapter CHAPTER 4: --- FeSi2 films fabricated by ion implantation --- p.18 / Chapter 4.1 --- Introduction --- p.18 / Chapter 4.2 --- Experimental details --- p.18 / Chapter 4.3 --- Ion energy series --- p.19 / Chapter 4.3.1 --- As-implanted sample --- p.19 / Chapter 4.3.1.1 --- Results --- p.20 / Chapter 4.3.1.2 --- Discussions --- p.20 / Chapter 4.3.2 --- Annealed samples --- p.24 / Chapter 4.3.2.1 --- Morphology of the annealed samples and the damage on Si substrate --- p.24 / Chapter 4.3.2.2 --- Identification of the FeSi2 phase and their orientation relationship with the Si matrix --- p.24 / Chapter 4.3.2.3 --- Photoluminescence of the samples --- p.26 / Chapter 4.3.2.4 --- Discussions --- p.26 / Chapter 4.4 --- Ion dosage series --- p.31 / Chapter 4.4.1 --- Results --- p.31 / Chapter 4.4.2 --- Discussions --- p.32 / Chapter 4.5 --- Summary --- p.36 / Chapter CHAPTER 5: --- Effect of post annealing on the phase and microstructure of FeSi2 --- p.37 / Chapter 5.1 --- Introduction --- p.37 / Chapter 5.2 --- Experimental details --- p.37 / Chapter 5.3 --- The correlation between microstructure of FeSi2 synthesized under different annealing conditions and their PL --- p.38 / Chapter 5.3.1 --- RTA series --- p.38 / Chapter 5.3.1.1 --- Results --- p.38 / Chapter 5.3.1.2 --- Discussions --- p.39 / Chapter 5.3.2 --- FA series --- p.42 / Chapter 5.3.2.1 --- Results --- p.42 / Chapter 5.3.2.2 --- Discussions --- p.44 / Chapter 5.3.3 --- RTAFA series --- p.45 / Chapter 5.3.3.1 --- Results --- p.45 / Chapter 5.3.3.2 --- Discussions --- p.45 / Chapter 5.4 --- The existence of alpha phase and its special shape --- p.51 / Chapter 5.4.1 --- Results --- p.51 / Chapter 5.4.2 --- Discussions --- p.52 / Chapter 5.5 --- The existence of gamma phase in 1050°C furnace annealed sample / Chapter 5.5.1 --- Results --- p.56 / Chapter 5.5.2 --- Discussions --- p.57 / Chapter 5.6 --- Summary --- p.59 / Chapter CHAPTER 6: --- Conclusions --- p.61 / References --- p.63

Ng Ka Shun = La₀.₄Ca₀.₆MnO₃/La₀.₈Ca₀.₂MnO₃多層薄膜之龐磁阻 / 吳家信. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Ng Ka Shun = La₀.₄Ca₀.₆MnO₃/La₀.₈Ca₀.₂MnO₃ duo ceng bo mo zhi pang ci zu / Wu Jiaxin. / Acknowledgements --- p.i / Abstract --- p.ii / 論文摘要 --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.viii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Review of magnetresistance --- p.1-1 / Chapter 1.2 --- Colossal magnetoresistance (CMR) --- p.1-4 / Chapter 1.3 --- Possible mechanism of CMR --- p.1-7 / Chapter 1.3.1 --- Double exchange --- p.1-7 / Chapter 1.3.2 --- Phase separation and percolation theory --- p.1-9 / Chapter 1.3.3 --- Current carrier density collapse --- p.1-12 / Chapter 1.4 --- Our motivation --- p.1-14 / Chapter 1.5 --- Brief review of several manganite multilayer systems --- p.1-15 / Chapter 1.6 --- Scope of this thesis work --- p.1-16 / References --- p.1-17 / Chapter Chapter 2 --- Instrumentation / Chapter 2.1 --- Thin film deposition --- p.2-1 / Chapter 2.1.1 --- Facing target sputtering (FTS) --- p.2-1 / Chapter 2.1.2 --- Connection of heating wires and thermocouple --- p.2-5 / Chapter 2.1.3 --- Vacuum system --- p.2-7 / Chapter 2.2 --- Annealing system --- p.2-9 / Chapter 2.3 --- Characterization --- p.2-11 / Chapter 2.3.1 --- X-ray diffraction (XRD) --- p.2-11 / Chapter 2.3.2 --- Resistance measurement --- p.2-13 / Chapter 2.3.3 --- Thickness estimation --- p.2-15 / References --- p.2-15 / Chapter Chapter 3 --- Growth and characterization of LCMO single layer thin film --- p.3-1 / Chapter 3.1 --- Fabrication and characterization of LCMO targets --- p.3-1 / Chapter 3.2 --- Preparation of LCMO thin film --- p.3-5 / Chapter 3.2.1 --- Deposition conditions --- p.3-5 / Chapter 3.2.2 --- Depostion procedure --- p.3-8 / Chapter 3.2.3 --- Characterization of single layer film --- p.3-9 / References --- p.3-12 / Chapter Chapter 4 --- La0.4Ca0.6MnO3 / La0.8Ca0.2MnO3 multilayers / Chapter 4.1 --- Sample preparation --- p.4-1 / Chapter 4.2 --- Results and discussion --- p.4-4 / Chapter 4.2.1 --- Structural characterization --- p.4-4 / Chapter 4.2.2 --- Transport properties --- p.4-10 / Chapter 4.3 --- Oxygen post-annealing of multilayer thin films --- p.4-13 / Chapter 4.3.1 --- Introduction --- p.4-13 / Chapter 4.3.2 --- Oxygen post-annealing conditions --- p.4-14 / Chapter 4.3.3 --- Results and discussion --- p.4-16 / Chapter 4.4 --- Conclusion --- p.4-26 / References --- p.4-27 / Chapter Chapter 5 --- Conclusion

Bacterial infection is a growing concern in hospital and community settings, where the issue of biofilms is a major problem. Most current methods of preventing microbial attachment and biofilm formation are limited due to application, process or inherent flaws. It was proposed that thin films containing an organometallic element could be deposited using plasma, a quick, clean surface modification technique; to create antimicrobial films which could then be applied to a range of substrates. <br /> Several novel antimicrobial monomer systems were synthesised and characterised based on silver, copper and zinc as the active constituent with phosphines, phosphites, maleimide and a novel Schiff base among the ligand systems. All monomers were found to greatly inhibit the growth of P. aeruginosa and S. aureus in solution and on solid media. Successful monomers were deposited onto suitable substrates (glass, gold, plastics, non-woven polypropylene) using continuous wave and pulse plasma, with the films characterised and low levels of active metal found in analysis using XPS and SIMS. Films were tested against solutions of pathogenic bacteria using a number of traditional and modern microbiological techniques and found to inhibit growth under a range of conditions, potentially due to the synergistic action of metal and ligand on bacterial cells. Effective control of bacteria was exhibited at times varying from 1h to 24h+. Highly volatile compounds were produced which allowed quick deposition of plasma films, which showed excellent activity against bacteria (99.9%+ growth reduction), indicating viability for potential application. All films tested showed no inhibition or toxicity to eukaryotic cells.

Cu2ZnSnS4 (CZTS), being related to the highly successful Cu(In,Ga)(S,Se)2, and CuInS2 materials, is a promising candidate for thin film photovoltaic devices. It has the advantage that it contains no rare or expensive elements, and therefore has cost-reduction potential for commercial systems. A two-stage process for fabrication of CZTS films is presented, which consists of sequential electrodeposition of Cu, Sn and Zn layers followed by a heat treatment in the presence of S vapour (‘sulfurisation’). Electrodeposition conditions are developed to give uniform Cu|Sn|Cu|Zn precursors of controlled morphology and composition, by the use of a rotating disc electrode system. Precursors are converted to CZTS by sulfurisation in the presence of elemental S, using a rapid thermal processing system (RTP). The sulfurisation reaction is studied by XRD and Raman spectroscopy as a function of temperature and at short time intervals, and a sequence of reactions is derived for the formation of CZTS. It is shown that the sulfurisation reaction occurs within minutes above 500°C. A model is presented for film formation when rapid heating rates are employed. The effects of sulfurisation time, background pressure and precursor composition on the morphological and structural properties of the CZTS films are investigated. Observations of grain size changes and compositional modification are made and explained in terms of the likely secondary phases present. The opto-electronic properties of the CZTS films are measured using a photoelectrochemical technique. Changes in the external quantum efficiency and band gap are studied as a function of sulfurisation parameters and precursor composition. After crystallisation of the CZTS phase during sulfurisation, the photocurrent obtained from the films continued to rise upon heating in the absence of S, which is explained by changes in acceptor concentration. Large shifts in the band gap are seen, and some proposals are made to explain the behaviour. The observations are discussed in the context of the particular compositions and sulfurisation conditions routinely used in the CZTS literature, and recommendations are made for further work.

β-W is an A15 structured phase commonly found in tungsten thin films together with the bcc structured W, and it has been found that β-W has the strongest spin Hall effect among all metal thin films. Therefore, it is promising for application in spintronics as the source of spin-polarized current that can be easily manipulated by electric field. However, the deposition conditions and the formation mechanism of β-W in thin films are not fully understood. The existing deposition conditions for β-W make use of low deposition rate, high inert gas pressure, substrate bias, or oxygen impurity to stabilize the β-W over α-W, and these parameters are unfavorable for producing β-W films with high quality at reasonable yield. In order to optimize the deposition process and gain insight into the formation mechanism of β-W, a novel technique using nitrogen impurity in the pressure range of 10-5 to 10-6 torr in the deposition chamber is introduced. This techniques allows the deposition of pure β-W thin films with only incorporation of 0.4 at% nitrogen and 3.2 at% oxygen, and β-W films as thick as 1μm have been obtained. The dependence of the volume fraction of β-W on the deposition parameters, including nitrogen pressure, substrate temperature, and deposition rate, has been investigated. The relationship can be modeled by the Langmuir-Freundlich isotherm, which indicates that the formation of β-W requires the adsorption of strongly interacting nitrogen molecules on the substrate. The dependence of β-W formation on the choice of underlayer materials has also been investigated. The β-W phase can only be obtained on the underlayer materials containing non-metallic elements. The dependence is explained by the existence of strong covalent bonds in β-W compared with that in α-W. The nickel and permalloy underlayers are the only exception to the above rule, and β-W has been successfully deposited on permalloy underlayer using very low deposition rate for spin-diffusion length measurement of β-W. The permalloy thin films usually take the (111) texture, since its (111) planes have the lowest surface energy. However, permalloy thin films deposited on β-W underlayer can achieve (002) texture using amorphous glass substrates. Therefore, the permalloy/β-W bilayer system can work as a seed layer for the formation of (002) textured films with fcc or bcc structure. The mechanism of the (002) texture formation cannot be explained by the existing models. The β-W to α-W phase transition was characterized by differential scanning calorimetry. The enthalpy of transformation is measured to be 8.3±0.4 kJ/mol, consistent with the value calculated using density functional theory. The activation energy for the β-W to α-W phase transformation kinetics is 2.2 eV, which is extremely low compared with that of lattice and grain boundary diffusion in tungsten. The low activation energy might be attributed to a diffusionless shuffle transformation process.