Development of Highly Sensitive C2H6 Sensor Based on 3D WO3 Nanocone for Transformer Applications : 변압기 응용 분야를 위한 3D WO3 나노 콘 기반의 고감도 C2H6 센서 개발
- 주제(키워드) WO3 , Nanocone , C2H6 sensor , Microheater , Temperature sensor
- 발행기관 아주대학교
- 지도교수 Keekeun Lee
- 발행년도 2020
- 학위수여년월 2020. 2
- 학위명 석사
- 학과 및 전공 일반대학원 전자공학과
- 실제URI http://www.dcollection.net/handler/ajou/000000029625
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
In recent years, concerns immensely about industrial safety, environmental contamination and harmful chemical control are triggering demand for highly sensitive and better exploited gas sensors. This is because of frequent uses of various types of gas sensor which is making gas sensor industry more demanding. Now a days, semiconductor-based gas sensors are used in a various field named as: diagnosing transformer incipient faults. Nonetheless, there is still some confrontation in the area of sensitivity, selectivity, long term stability, response, recovery and high-power consumption. Therefore, it is very much essential to improve the semiconductor base gas sensor by applying various technology. In this research, 3D structure of WO3 has been developed for better C2H6 sensing purpose. WO3 occupied gas sensors are familiar to work proficiently at 200°C-500°C temperature. In this study, by making of 3D nanocone structures, an optimum response to C2H6 has been obtained at a lower operating temperature of below 300°C. Nanoconed structured WO3 showed the highest sensitivity towards C2H6 in comparison of bare WO3 thin film due to its crystalline form and higher number of oxygen molecules vacancies. One of the most imperative factors for metal oxide semiconductor (MOSs) based gas sensors is the operating temperature. In this thesis, the novel design of in-plane microheater integrated with microheater has been demonstrated for suitable temperature and later COMSOL simulation were performed to predict the heater performance. This study has showed enhanced sensitivity and selectivity of 3D WO3 nanocone structure towards C2H6 at low operating temperature which is achieved by developing of in-plane microheater. This thesis encloses with making of a 3D nanocone for the first time, to the best of our knowledge, for enhancing sensor performance for transformer applications.
more목차
Chapter 1 Introduction 1
1.1 Needs of C2H6 gas sensor 1
1.2 Consideration of parameters in semiconductor-based gas sensor 2
1.3 Research objectives 5
1.4 Organization of the thesis 6
Chapter 2 State of the art on C2H6 gas sensor with WO3 7
2.1 Introduction 7
2.2 Functional mechanisms of metal oxide gas sensors 7
2.2.1 Receptor function 7
2.2.2 Transduction function 8
2.2.3 Utility function 9
2.3 Chemical mechanisms of a metal oxide gas sensors 9
2.4 Highly sensitive WO3 gas sensors 11
2.5 Summary 14
Chapter 3 Experimental Methods 15
3.1 Introduction 15
3.2 Gas sensing mechanism 15
3.3 Fabrication of Gas sensor 17
3.3.1 Materials 17
3.3.2 Fabrication procedures 18
3.3.3 Formation of 3D WO3 Nanocones (NCs) 19
3.4 Characterization of WO3 thin film 20
3.5 Testing setup for gas sensing 21
3.6 Summary and outlook 21
Chapter 4 COMSOL Multiphysics Simulation 23
4.1 Introduction 23
4.2 Simulation Methods 23
4.2.1 Microheater simulation 23
4.2.2 3-dimentional WO3 nanocone structure 28
Chapter 5 Experimental Results 30
5.1 Introduction 30
5.2 Fabricated sensor system 30
5.3 SEM and AFM analysis 32
5.4 Material Characterizations 34
5.4.1 X-ray diffraction (XRD) analysis 34
5.4.2 Raman spectroscopic analysis 35
5.5 Performances of In-plane microheater 36
5.6 Characterization of C2H6 gas sensor 37
5.6.1 Sensor performance in terms of temperature 38
5.6.2 WO3 and WO3 nanocones sensor performances 39
5.6.3 Calibration 42
5.6.4 Selectivity 43
5.6.5 Repeatability 44
5.7 Summary and outline 46
Chapter 6 Conclusions and Future Work 47
6.1 Conclusions 47
6.2 Approaches for future work 47
Reference 49
