The professors of the Department of Microelectronics and Biomedical Engineering of the UTM Faculty of Computers, Informatics and Microelectronics – prof. univ., Dr. Oleg LUPAN, univ. assist., Nicolae MAGARIU, univ. lect., Nicolai ABABII, published a new paper in the prestigious scientific journal ACS Applied Materials & Interfaces, with impact factor 9.44.
The scientific paper ,,Al2O3/ZnO Heterostructure-Based Sensors for Volatile Organic Compounds in Safety Applications”, with a count of 60 pages, highlights the research of the UTM professors, carried out in collaboration with the teams of the professors Rainer Adelung, Lorenz Kienle from Germany, F. Faupel from Germany, Nora H. de Leeuw from the Netherlands, England, Abhishek Kumar Mishra from India, regarding the new sensor based on Al2O3/ZnO heterostructures. It touches upon the production technology and the influence of the thickness of the aluminum oxide layer (Al2O3) for the detection of volatile organic compounds, namely 2-propanol vapors. The detection of these vapors is quite imperative, as even a small amount presents a high fire hazard or acts as depressants of the central nervous system; it may also cause flushing, dizziness, CNS depression, hypothermia, low blood pressure, shock, respiratory depression and coma. Monitoring volatile organic compounds (VOCs) in harsh, industrial, or domestic environments, especially for safety applications, is a growing field that requires specialized sensor structures.
The inventors have developed a new approach to tune the sensor selectivity by changing the thickness of the exposed amorphous Al2O3 layer from 5 to 18 nm. The experimental part was supported by thorough calculations, namely the density functional theory (DFT) calculations of the Al2O3/ZnO interface and its interaction with VOC, which show that the molecular affinity for the given interface decreases from 2-propanol (2-C3H7OH) ≈ n-butanol > ethanol > acetone > hydrogen. The charge transfers between the surface and the adsorbates, and local densities of states of the interacting atoms, support the calculated strength of the molecular preferences. The authors’ findings are very important for the development of 2-propanol sensors and for understanding the effect of the heterojunction and the thickness of the top nanolayer on the gas response, which thus far have not been reported in the literature.
Likewise, the paper mentions that the given sensors remain stable over time, the response to 2-propanol vapors staying unchanged for more than 2 years. Obviously, during the research carried out at UTM, the PhD students, who will soon become Doctors in Engineering Sciences, have gained enormous experience both professionally and in working and collaborating with different teams of researchers from different countries.
In this context, the authors mentioned several aspects of the research conducted.
Nicolae MAGARIU, univ. assist. within the MIB Department, UTM:
- This research, conducted with colleagues from prestigious universities in Germany, the Netherlands, the UK and India, allowed for the accumulation of new knowledge about Al2O3/ZnO, interface effects, the development of new sensor devices to detect volatile organic compounds that will enable the design of new alarm systems for the prevention of hazardous VOC concentrations, thus protecting the human personnel of companies and enterprises. These results will also contribute to the development of science as a whole.
Nicolai ABABII, university lecturer within the MIB Department, UTM:
- The results presented in the paper indicate that we can obtain sensors for the detection of volatile organic compounds, in particular, propanol, using simple and cost-effective methods that can be developed and widely implemented in the Republic of Moldova.
The UTM professors work in the Department of Microelectronics and Biomedical Engineering (DMIB) within the Faculty of Computers, Informatics and Microelectronics (FCIM) and transfer the knowledge and experience gained in international collaborations to young scholars from the FCIM and DMIB Bachelor, Master’s and Doctorate programs.
The Department of Microelectronics and Biomedical Engineering within the Faculty of Computers, Informatics and Microelectronics is an effective partner in international collaborations, as it provides the educational process for three study programs: Applied Electronics (EA), Microelectronics and Nanotechnologies (MN) and Biomedical Engineering (IBM) (Bachelor and Master’s degrees) and 5 Doctorate programs. The young people that are diligent and curious to develop or research such devices can pursue this field at the Center for Nanotechnologies and Nanosensors within the MIB Department, FCIM-UTM.
ACS Applied Materials and Interfaces (ACS AMI) is a scientific journal published by the famous US publishing house ACS, serving the interdisciplinary community of chemists, engineers, physicists and biologists focusing on how newly-discovered materials and interfacial processes can be developed and used for specific applications. ACS AMI is also truly international, with the majority of published articles now coming from outside the United States, capturing the rapid growth in applied research around the globe; Editor-in-Chief: Professor Kirk S. Schanze.
This internationally appreciated research was partially supported by the G5634 SPS Project “Advanced Electro-Optical Chemical Sensors” AMOXES and UTM.
The universities and research centers involved are:
1 Center for Nanotechnology and Nanosensors, Department of Microelectronics and Biomedical Engineering, Faculty of Computers, Informatics and Microelectronics, Technical University of Moldova, 168 Stefan cel Mare str., MD-2004, Chisinau, Republic of Moldova
2 Department of Materials Science, Chair for Functional Nanomaterials, Faculty of Engineering, Christian-Albrechts Universität zu Kiel, Kiel, Kaiserstraße 2, D-24143 Kiel, Germany
3 Department of Physics, University of Central Florida, Orlando, Florida, FL 32816-2385, USA
4 School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
5 Department of Physics, School of Engineering, University of Petroleum and Energy Studies (UPES), Energy Acres Building, Bidholi, Dehradun 248007, Uttrakhand, India
6 Department of Materials Science, Chair for Synthesis and Real Structure, Faculty of Engineering, Christian-Albrechts Universität zu Kiel, Kiel, Kaiserstraße 2, D-24143 Kiel, Germany
7 Department of Materials Science, Chair for Multicomponent Materials, Faculty of Engineering, Christian-Albrechts Universität zu Kiel, Kiel, Kaiserstraße 2, D-24143 Kiel, Germany
8 Fraunhofer Institute for Silicon Technology (ISIT), Itzehoe, Fraunhoferstraße 1, D- 25524, Germany
9 Department of Earth Sciences, Utrecht University, Princetonlaan 8a, 3584 CB Utrecht, The Netherlands