Моделювання характеристик хімічного сенсору на основі оксиду цинку
| dc.contributor.advisor | Тимофєєв, Володимир Іванович | |
| dc.contributor.author | Лисак, Олександр Олексійович | |
| dc.date.accessioned | 2023-08-30T08:16:37Z | |
| dc.date.available | 2023-08-30T08:16:37Z | |
| dc.date.issued | 2021 | |
| dc.description.abstract | Об’єктом розгляду є моделювання чутливості газового сенсору на основі оксиду цинку. Метою роботи є проведення аналізу характеристик сенсору від електрофізичних параметрів на основі математичної моделі. Об’єктом є чутливість газового сенсору з нанодротами на поверхні чутливого елементу. Перший розділ присвячений методам виготовлення наноструктур, розгляду існуючих варіантів сенсорів, обрано стрижневу топологію наноструктури, наведено характеристики деяких існуючих сенсорів кисню. У другому розділі наведено математичну модель для розрахунку параметрів газового сенсору, аналітичні вирази і апроксимації для розрахунку характеристик сенсору, особливості газового сенсору з нанодротами. У третьому розділі наведено результати моделювання та аналіз чутливості сенсора у залежності параметрів структури та температури. | uk |
| dc.description.abstractother | The object of consideration is the sensitivity of the gas sensor based on ZnO. The aim of the work is to analyze the characteristics of the sensor from certain parameters of the created model. The object of the study is the sensitivity of the gas sensor depending on the presence of nanowires on the surface of the sensitive element. The first section is devoted to the methods of nanostructure fabrication, consideration of existing sensor variants, the rod model of nanostructure is chosen, then the characteristics of some existing oxygen sensors are given. The second section explained the developed model for calculating the parameters of the gas sensor, gave the formulas for which calculations are performed in the Matlab program. The general principle of operation of the gas sensor on nanotubes was explained. The third section presents the results of the program, which simulated the sensitivity characteristic depending on the entered parameters. The dependence of everyday life on the products of the semiconductor industry has led to tremendous growth in this industry. Progress requires the development of smaller and smaller devices with higher speed, flexibility, better performance and lower cost. This demand has led to the development of new technologies and materials to meet the demands of the growing semiconductor industry. Nanotechnology, in which products contain very small particles and exhibit special properties, is one of the most recent and active research areas. In this regard, thin-film technology plays an important role, which allows very thin layers (from a few nanometers to the angstrom level) of semiconductor material to be deposited onto a support substrate. The resulting material demonstrates new mechanical, chemical, optical and electrical properties down to the nanometer scale as a result of surface and quantum confinement effects. A thin film is defined as a very thin layer (10 nm to 1–2 μm) of material applied to a carrier material (substrate) by controlled condensation of vapors, ions or molecules through a physical or chemical process. This technology is known as thin film technology. Thin films are applied to a wide variety of substrates. Depending on the material, thin films can be classified into different categories: for example, metallic, dielectric, organic or semiconducting films. The material can be in monocrystalline, polycrystalline or amorphous forms. The properties of thin films are completely different from their bulk shape. Bulk materials have fixed properties, while the properties of thin films and devices depend on surface quality, not volume. In addition, the properties of thin films can be controlled by various methods such as doping, changing the thickness, or surface treatment. Multilayer thin films can exhibit completely unknown properties. Thin-film technology also makes efficient use of raw material. The progressive development of thin-film technology has resulted in its extensive use in fields of optics, electronics, aircraft, defence, space science and other industries. The categories A Short Review on Properties and Applications of Zinc Oxide Based Thin Films and Devices ZnO as a promising material for applications in electronics, optoelectronics, biomedical and sensors in which thin-film technology finds applications are mechanical, chemical, thermal, electrical, magnetic, electronic, chemical, optical and optoelectronic. The main applications of thin- film technology primarily include optical coatings and semiconductor thin film devices. A thin film of materials can be deposited from the gas, vapour, liquid or solid phase. With advances in nanotechnology and thin film deposition techniques, significant interest has been developed in recent years for the development of photovoltaic devices, batteries, sensors, information storage, lighting and large-area electronics. Various materials like silicon, GaN, gallium arsenide and oxide-based semiconductors (including ZnO) have continued to receive considerable attention for fundamental as well as applicationoriented research. However, research interest in ZnO is enormously growing because of its excellent optical, electrical, magnetic, piezoelectric, catalytic and gas-sensing properties that make it specifically attractive for nanoelectronic, optoelectronic, nanophotonic and piezoelectric devices. A gas sensor is a device that can be used to detect various gases, such as ethanol, liquefied gas, CO2 and CO gases, and so on. The basis of their work is the ability to change the conductivity of sensitive material in the presence of a certain gas. The first generation of MOS gas sensors was based on thick SnO2 films. The main advantages of MOS gas sensors are small size and low power consumption, as well as simple design, good sensitive properties and high compatibility with various materials and technologies. Recently, various morphologies of MES (metal oxide-semiconductor) nanostructures have emerged, such as wire, tape, rod, and tetrapods (structures of four separate bonded nanowires) that have been extensively studied for use in gas sensors. It is well known that the sensitivity characteristics of these sensors strongly depend on the morphology of the structure of the MES. Thanks to new nanotechnologies, the sensitivity of gas sensors has been significantly increased. These nanotechnologies are based on various methods, such as the method of pulsed laser deposition, chemical vapor depositio, thermal evaporation, metal catalysis. Gas sensors have many important applications, such as environmental pollution control, fire detection, air analyzer in the breathalyzer, industrial production control process or to detect harmful gas leaks in the mine, and others. Oxide-based semiconductor gas sensors are easy to manufacture, have a relatively low cost and their surfaces have good sensitivity to the measured gas. It consists of three main components of sensitive material, electrodes and a heater. To increase the sensitivity of the film surface should have a high surface porosity for better adsorption of gases. Zinc oxide (ZnO) is physically and chemically stable and is a promising choice for implementation in the form of a thin film of a gas sensor. Doping ZnO with appropriate elements in appropriate amounts increases the surface porosity of the material, thereby improving the selectivity of probing and the response time of the film. The main characteristics of gas detection are gas reaction, response time, recovery time, selectivity, detection limit, stability and recyclability. The use of various ZnO nanomaterials, such as nanostrings, nanowires, quantum dots, thin films and nanowires, can improve the parameters of the gas sensor. Various factors, such as the concentration of the detected gas, annealing temperature, ZnO morphology and particle size, relative humidity, operating temperatures significantly affect the characteristics of the sensors. Typically, gas sensors based on MOS nanostructures show high sensitivity and sometimes up to several hundred times higher than the sensitivity of a conventional MOS sensor at a moderate concentration. On the other hand, sensors based on larger MOS structures, for example, on thin films or micro-tetrapods show less sensitivity. The relevance of the study of ZnO is due to the possibility of creating transparent conductive coatings - thin films with high values of conductivity and transparency in the visible region of the spectrum. Crystalline indium tin oxide and amorphous indium zinc oxide are currently used as materials for transparent electrodes. However, due to the high cost of indium, the search for alternative transparent conductive coatings with a minimum content of indium is an urgent task. Doped zinc oxide materials are an alternative to ITO. Considerable attention is also paid to doped nanocrystalline zinc oxide in connection with the possibility of creating miniature gas sensors. In recent years, a number of reviews and books have been published on zinc oxide and its properties. In the literature, there are works devoted to the study of the electrophysical properties of zinc oxide doped with gallium and indium. It is noted that the introduction of doping impurities leads to a complex distribution of doping impurities between the surface and the volume of the semiconductor, affects the microstructure, surface reactivity, optical, electrophysical and, therefore, sensory properties of materials. The main research in this area is of a technological nature and is aimed at selecting the optimal composition (concentration of donor impurities) or processing conditions (temperature and annealing atmosphere) to obtain the required values of the conductivity or mobility of charge carriers. Further progress in the field of gas sensors is ensured through the use nanostructured architectures, such as one-dimensional and quasi-one-dimensional blocks, nanowires, nanotubes, nanofibers, hollow spheres, hemispheres, thin-walled nanostructures, etc. Features of these structures are large surface area, high porosity and effective depletion. Note that, despite progress in the development of such sensors, some issues remain insufficiently studied. In particular, there are difficulties in constructing general ones mathematical models that would describe the operation of sensors; developed models are either very simplified or the same applies only to certain processes that occur during contact of the sensor with the environment Wednesday. This is obviously due to the wide range of physical phenomena manifested in real operating conditions of the sensor, and significant possible variations in operating conditions. In addition, experimental studies of sensors based on different materials and / or different architectures are not typically systemic, focusing on analyzing the results obtained for specific embodiments. | uk |
| dc.format.extent | 50 с. | uk |
| dc.identifier.citation | Лисак, О. О. Моделювання характеристик хімічного сенсору на основі оксиду цинку : дипломна робота … бакалавра : 153 Мікро- та наносистемна техніка / Лисак Олександр Олексійович. – Київ, 2021. – 50 с. | uk |
| dc.identifier.uri | https://ela.kpi.ua/handle/123456789/59650 | |
| dc.language.iso | uk | uk |
| dc.publisher | КПІ ім. Ігоря Сікорського | uk |
| dc.publisher.place | Київ | uk |
| dc.subject | хімічний сенсор | uk |
| dc.subject | оксид цинку | uk |
| dc.title | Моделювання характеристик хімічного сенсору на основі оксиду цинку | uk |
| dc.type | Bachelor Thesis | uk |
Файли
Контейнер файлів
1 - 1 з 1
Вантажиться...
- Назва:
- Lysak_bakalavr.pdf
- Розмір:
- 2.22 MB
- Формат:
- Adobe Portable Document Format
- Опис:
Ліцензійна угода
1 - 1 з 1
Ескіз недоступний
- Назва:
- license.txt
- Розмір:
- 9.1 KB
- Формат:
- Item-specific license agreed upon to submission
- Опис: