Application of ZnO nanorods and nanowires. a) Nano laser, (b) transparent flexible transistor and (c) nano sensor. Schematic of the reactor system used to grow ZnO nanorods on different substrates. The role of plasma in ion plating. a) Pattern of dot mask, (b) ZnO nanoproducts and electrode Fig 15.
The XRD result around the ZnO seed layer acc. a) applied power, (b) vacuum level in the chamber Fig 20. Effect of ZnO seed layer when growing ZnO nanorods. a) surface of nanorods, (b) side of nanorods. FE-SEM result about ZnO nanorods according to concentration at the growth temperature of 90℃.
0.3 M% 성장 농도에서 온도에 따른 ZnO 나노막대의 FE-SEM 결과. 4장에서는 ZnO 나노로드 성장을 위한 최적의 조건을 결정하기 위해 증착 조건에 따라 초기 층의 구조적 특성을 분석하였다.
Introduction 1
However, in order to make practical use of this technology, there are many technical problems to be solved, such as the assembly technology to implement a nano-device, the fine reversal of the crystal growth of the one-dimensional structure, and the establishment of the correlation. of the impact on the physical properties of synthesized one-dimensional nanomaterial values and physical properties[11-14]. The growth methods of one-dimensional ZnO nanostructures can be accessed from the bottom up, various methods have been proposed for control, because different shapes and sizes can be grown according to the growth conditions. While the hydrothermal method is one of the liquid methods to obtain a solid solution composition that has a uniform crystallinity.
However, as mentioned above, it is required to fabricate the nanostructure of the quality structures and control the size of the nanostructure. Therefore, the experiments in this study were conducted to obtain the conditions of ZnO nanorods grown by hydrothermal methods for the growth and control of good quality ZnO one-dimensional nanostructures by a simple process on the PES substrate. Especially the PES substrate, the crystal structure of the amorphous as well as the surface morphology is not good.
In the growth of ZnO nanorods, the effect of the seed layer was investigated and the ZnO nanorods were studied according to the structural properties of the ZnO seed layer. Furthermore, the electrical and structural properties of the growth of ZnO nanorods were analyzed and the possibility of controlling the size and control properties was suggested.
Background of Theory 3
Nanomaterials 3
- Properties of nanomaterials 3
- Manufacturing of nanomaterials 6
The electrode made of dot mask and dot mask is shown in fig. 14, the conditions for forming the electrode are shown in Table 4. a) The pattern of the dot mask, (b) the ZnO nanorods and the electrode. In general, the resistance of ZnO nanorods increased according to the linear increase in concentration. As a result of HP4145 semiconductor parameter analyzer, the resistance of ZnO nanorods increases.
Generally, the resistance of ZnO nanorods increased according to the linear increase in temperature. Due to HP4145 semiconductor parameter analyzer, the resistance of ZnO nanorods is reduced. Thus, the resistance of ZnO nanorods at the growth temperature of 90 ℃ is shown representatively in Table 6.
Due to the component of ZnO nanorods using EDS, Zn, O and C were detected from the sample. The results show that the diameter and the length of ZnO nanorods are controlled by adjusting the variables.
Zinc Oxide(ZnO) 9
- Properties of ZnO 9
- One-dimensional nanostructures of ZnO 12
Theory of equipment 13
- Sputter system 13
- E-beam evaporator 16
The state of materials of target, when Ar ions pour out of target, are neutral atoms. The sputtering rate is increased when the energy of Ar cation colliding into a target is increased. So it can save time and economy, but it is difficult to control the surface of thin films.
Ions are mostly ionized in plasma, only a small part is detected, ions, which have much higher energy than neutral particles, ionized ions and other particles. Very high energy ions emitted by the target are captured by the electric field. Usually, the amount of ionized particles increases due to acid, alkali cleaning, oxidation treatment or contamination.
When one has a high tendency to ionize, the other consists of a material with a high electron affinity in the alloy or compound. When the target is the materials of (A+B), A has a high ionization tendency, B is the higher the electron affinity fraction is high. When using a ceramic target or as reactive sputtering, the non-metallic anions can be generated within the surface of the target or plasma.
The kinetic energy of the deposition particles reaching the substrate is the same as the magnitude of the heat rate, because in the case of vacuum deposition, the source is vaporized by heating. Ion plating are the methods that ionized deposition, what part of the generated atoms or molecules, accelerated in the electric field to make the state of energy at a high level. Depositing particles are evaporated by electron beam heating method or electron beam evaporation or the like used in the vacuum vapor deposition.
And the part of depositing particles is ionized by plasma or an electron beam of inactive gas and the reactive gas between the evaporation source and the substrate. The particles having a large energy formed thin films with dense and excellent physical properties due to easy movement within the thin films. But it can be activated the surface of thin films due to collide at high speed of Ar, and ionized particles.
Experiment and Measuring properties 18
- Growth of Seed layer 18
- Growth of Seed layer 18
- Growth of ZnO nanorods 20
- Hydrothermal methods 20
- Reagents and reaction 22
- Growth of ZnO nanorods 23
- Formation of electrode 25
- Formation of electrode 25
- Characterization methods 26
- Field Emission Scanning Electron Microscope 28
- Atomic Force Microscope 29
- EDS(Energy-Dispersive x-ray Spectroscopy) 30
The spinning rod in the Si oil rotated to heat and the Si oil was applied to create a homogeneous temperature around the round bottom flask. In particular, the end of the temperature sensor is positioned in the same way as the position with the substrate to minimize the range of temperature difference. After the stabilization of the solution in the round-bottom flask, the sample is secured using a sample holder, and the sample holder is fixed so that it is in the central part of the solution.
The substrate is facing the bottom of the round bottom flask and attached to the bottom of the sample holder. When the substrate is facing the bottom of the round bottom flask, the ZnO nanorods grow uniformly. When the temperature of the solution is stable, the substrate is placed in the middle of the beaker and the substrate is then facing down.
Summary of the experimental process is shown in Fig. 11, and experimental conditions are given in table 3. The electrode of Al(aluminium)/Ti(titanium) is formed by e-beam evaporator for the study of electrical properties of ZnO nanorods on PES substrate. Because Ti electrode, which has a good conductivity, is used to improve the contact between the Al electrode and ZnO nanorods.
FE-SEM (Field Effect Scanning Electron Microscope) and HP 4145B Semiconductor Parameter Analyzer were used to analyze the shape, crystal and electrical properties of ZnO nanorods grown by hydrothermal methods. The HP 4145B Semiconductor Parameter Analyzer is an instrument that can determine the electrical properties of a semiconductor device in conjunction with LabVIEW. Electrons interact with atoms in the sample and produce various detectable signals that contain information about the topography and composition of the sample surface.
The atomic force microscope measured the shape of the sample surface using a cantilever by taking an image of the sample surface and measuring the displacement in the cortical direction of the probe at regular intervals. By moving the tip of the needle, the shape of the pattern can be determined by feedback to the actuator. Because he used gravity and the force is very less than contact mode force.
As the needle approaches the surface of the sample, the amplitude and the phase are changed. Therefore, it is possible to observe all the conductor, non-conductor, at a high resolution.
Result and discussion 31
The properties of seed layer 32
- The properties of ZnO seed layer 32
The properties of ZnO nanorods according
- The structural properties of ZnO nanorods 34
- The electrical properties of ZnO nanorods 37
ZnO nanorods were grown to analyze the properties according to increasing growth concentration such as and 0.5 M% by hydrothermal methods. An HP 4145B semiconductor parameter analyzer, FE-SEM, AFM and EDS were used to analyze the structural and electrical properties. The diameter of the ZnO nanorods growing with increasing density increases linearly up to 0.5 M% of the maximum concentration, and the length change had a relatively uniform magnitude regardless of the concentration around 80 nm.
Thus, ZnO nanorods are grown in the vertical direction only after these particles of ZnO were added to the growth in the radial direction. In the EDS results in Fig. 23, C and Pt were detected in ZnO nanorods. Generally, the amount of Zn and O increases to 1.2k from 1.05k according to the increase in concentration.
Different peaks have been observed more directional as the polycrystalline structure due to supersaturated solution at a concentration of 0.5 M%. The current was measured according to the applied voltage to +4V from -4V at the two electrodes formed using dot mask for electrical property analysis. The current was increased by flowing through the ZnO nanorods in accordance with the increase in concentration, and the current is proportional to the voltage.
The properties of ZnO nanorods according
- The structural properties of ZnO nanorods 39
- The electrical properties of ZnO nanorods 42
Conclusion 44
ZnO nanorods would not grow above the threshold until the disappearance of the Zn source at the concentration of 0.05 M%. Moreover, the maximum diameter of ZnO nanorods is about 200 nm, and the maximum length of ZnO nanorods is about 400 nm, when a sufficient source of thermal energy and Zn is applied. In this study, ZnO nanorods were grown according to concentration and growth temperature by hydrothermal methods.
