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Chu SY, Wu MJ, Yeh TH, Lee CT, Lee HY. Sensing Mechanism and Characterization of NO 2 Gas Sensors Using Gold-Black NP-Decorated Ga 2O 3 Nanorod Sensing Membranes. ACS Sens 2024; 9:118-125. [PMID: 38150672 DOI: 10.1021/acssensors.3c01742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
In this work, a vapor cooling condensation system was utilized to deposit various amounts of p-type gold-black nanoparticles (NPs) onto the surface of n-type gallium oxide (Ga2O3) nanorods forming p-n heterojunction-structured sensing membranes of nitrogen dioxide (NO2) gas sensors. The role and the sensing mechanism of the various gold-black NP-decorated Ga2O3 nanorods in NO2 gas sensors were investigated. The coverage and atomic percentage of the sensing membranes were observed using high-resolution transmission electron microscopy (HRTEM) measurements and energy-dispersive spectroscopy (EDS), respectively. For the NO2 gas sensor using the sensing membrane of 60 s-deposited gold-black NP-decorated Ga2O3 nanorods under a NO2 concentration of 10 ppm, the highest responsivity of 5221.1% was obtained. This result was attributed to the spillover effect and the formation of the p-n heterojunction, which increased more ionized-oxygen adsorption sites and promoted the reaction between NO2 gas and Ga2O3 nanorods. Furthermore, the NO2 gas sensor could detect the low NO2 concentration of 100 ppb and achieved a responsivity of 56.9%. The resulting NO2 gas sensor also exhibited excellent selectivity for detecting NO2 gas, with higher responsivity at a NO2 concentration of 10 ppm compared with that of the C2H5OH and NH3 concentrations of 100 ppm.
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Affiliation(s)
- Shao-Yu Chu
- Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
| | - Mu-Ju Wu
- Program on Key Materials, Academy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
| | - Tsung-Han Yeh
- Department of Electrical and Electronic Engineering, Chung Cheng Institute of Technology, National Defense University, Taoyuan 335, Taiwan, Republic of China
| | - Ching-Ting Lee
- Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
- Department of Electrical Engineering, Institute of microelectronics, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 320, Taiwan, Republic of China
| | - Hsin-Ying Lee
- Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
- Program on Key Materials, Academy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
- Meta-nanoPhotonics Center, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
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Zhang X, Zhou Y, Chen Y, Li M, Yu H, Li X. Advanced In Situ TEM Microchip with Excellent Temperature Uniformity and High Spatial Resolution. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23094470. [PMID: 37177673 PMCID: PMC10181734 DOI: 10.3390/s23094470] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/22/2023] [Accepted: 04/29/2023] [Indexed: 05/15/2023]
Abstract
Transmission electron microscopy (TEM) is a highly effective method for scientific research, providing comprehensive analysis and characterization. However, traditional TEM is limited to observing static material structures at room temperature within a high-vacuum environment. To address this limitation, a microchip was developed for in situ TEM characterization, enabling the real-time study of material structure evolution and chemical process mechanisms. This microchip, based on microelectromechanical System (MEMS) technology, is capable of introducing multi-physics stimulation and can be used in conjunction with TEM to investigate the dynamic changes of matter in gas and high-temperature environments. The microchip design ensures a high-temperature uniformity in the sample observation area, and a system of tests was established to verify its performance. Results show that the temperature uniformity of 10 real-time observation windows with a total area of up to 1130 μm2 exceeded 95%, and the spatial resolution reached the lattice level, even in a flowing atmosphere of 1 bar.
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Affiliation(s)
- Xuelin Zhang
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yufan Zhou
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Chen
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haitao Yu
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinxin Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
- School of Microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China
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