Tin Oxide Modification of Indium Oxide Gas Sensitive Layers to Increase Efficiency of Gas Sensors

Monitoring of air pollutions is one of actual trends in the development of industrial and domestic instrumentation. There are sets of tasks for improving gas analytical instruments because of increasing demand for control of a concentration of explosive and toxic gases on a level with maximum allowable concentration. The aim of the paper was to investigate the methods of formation and elemental composition of indium oxide films modified with tin oxide on the surface of gas sensor elements as one of the promising compounds for improving the detection efficiency of explosive and toxic gases in the environment. The processes of formation of gas-sensitive films deposited on the surface of nichrome alloy information electrodes were studied in this article. Substrates of anodic aluminum oxide with area of 10 × 10 mm2 and a thickness of 45 ± 0,5 μm were chosen for research. Two layers on the surface of the samples were formed. The first layer was formed from NiCr alloy (Ni – 80 %, Cr – 20 %) with a thickness of ≈ 0.3 μm by ion-plasma sputtering. The second layer was based on indium oxide with addition of tin oxide with thicknesses from ≈ 0.3 μm to ≈ 1.0 µm and coated with sol-gel technology. Five samples of gas-sensitive films were formed with different methods of deposition and heat treatment. Scanning electron microscopy was used for study of films’ morphology and elemental compositions of samples. The most perfect continuous semiconductor films were obtained by multilayer applying of a sol-gel paste. When semiconductor films were processed at annealing temperatures of 700 °C and higher in vacuum so there was observed cracking of semiconductor films up to a layer of NiCr alloy. The developed surface of gas-sensitive films allows to reach high sensitivity and affectivity of semiconductor sensors for control of air gas composition.

1. Kitikov VO, Ternov EV, Danilenko AV, Mukhurov NI, Denisyuk SV. New Functional Possibilities of fire Detectors for Residential and Industrial Rooms. Devices and Methods of Measurements. 2019;10(4):341-352. (In Russ.). DOI: 10.21122/2220-9506-2019-10-4-341-352

2. Javaid M, Haleem A, Singh RP, Rab S, Suman R. Exploring the potential of nanosensors: A brief overview. Sensors International. B. 2021;2:100130 р. DOI: 10.1016/j.sintl.2021.100130

3. Wang Z, Zhao C, Han T, Zhang Y, Liu S, Fei T, Lu G, Zhang T. High-performance reduced graphene oxide-based room-temperature NO2 sensors: a combined surface modification of SnO2 nanoparticles and nitrogen doping approach. Sensors and Actuators B: Chemical. 2017;242:269-279. DOI: 10.1016/j.snb.2016.10.101

4. Averin IA, Pronin IA, Yakushova ND, Karmanov AA, Alimova EA, Igoshina SE, Moshnikov VA, Terukov EI. Sol-Gel Technology Adaptation of Nanostructured Zinc Oxide for Flexible Electronics. Technical Physics. 2019;64:1821-1826. (In Russ.). DOI: 10.21883/JTF.2019.12.48492.227-19

5. Reutskaya OG, Pleskachevsky YM. Measurement of CO and NO2 gas concentration's by multisensory microsystem in the mode of pulse heating. Devices and Methods of Measurements. 2017;8(2):160-167. (In Russ.). DOI: 10.21122/2220-9506-2017-8-2-160-167

6. Lagutin AS, Vasil'ev AA. Solid State Gas Sensors. Review. Journal of Analytical Chemistry. 2022;77(2):100116. (In Russ.). DOI: 10.1134/S1061934822020083

7. Dhall S, Mehta BR, Tyagi AK, Sood K. A review on environmental gas sensors: Materials and technologies. Sensors International. 2021;2:1-10. DOI: 10.1016/j.sintl.2021.100116

8. Forsh EA, Marikutsa AV, Martyshov MN, Forsh PA, Rumyantseva MN, Gaskov AM, Kashkarov PK. Study of The Sensitivity of Nanocrystalline Indium Oxide with Diff Sizes of Nanocrystals to Nitrogen Dioxide. Nanotechnologies in Russia. 2015;7(3–4):87-90. (In Russ.).

9. Qin W, Yuan Z, Gao H, Meng F. Ethanol sensors based on porous In2O3 nanosheet-assembled micro-flowers. Sensors. 2020;20(12):3353-3366. DOI: 10.3390/s20123353

10. Trakhtenberg LI, Gerasimov GN, Gromov VF, Belysheva TV, Ilegbusi OJ. Conductivity and sensing properties of In2O3 + ZnO mixed nanostructured films: Effect of composition and temperature. Sensors and Actuators B Chemical. 2013;187(1):514-521. DOI: 10.1016/j.snb.2013.03.017

11. Kumeria T, Santos A, Losic D. Nanoporous anodic alumina platforms: engineered surface chemistry and structure for optical sensing applications. Sensors. 2014; 14:11878-11918. DOI: 10.3390/s140711878

12. Ullah A, Kasi A, Kasi JK, Bokhari M. Fabrication of mechanically stable AAO membrane with improved fluid permeation properties. Microelectronic Engineering. 2018;187-188:95-100. DOI: 10.1016/j.mee.2017.11.019

13. Reutskaya OG, Taratyn IA, Pleskachevsky YM. Multisensor Microsystem for Measuring the Concentration of Gases CO, H2, C3H8, CO2. Devices and Methods of Measurements. 2016;7(3):271-278. (In Russ.). DOI: 10.21122/2220-9506-2016-7-3-271-278

14. Denisyuk SV, Muhurov NI, Kudanovich ON, Kolesnik EE. Adsorption-Resistive Sensor with Two Working Areas. Instruments. 2015;2:7-12. (In Russ.).

15. Gasenkova IV, Ostapenko EV. Effect of annealing on the phase composition and morphology of Al2O3 formed in a complex electrolyte. Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. 2013;7:536-541. DOI: 10.1134/S1027451013030245

16. Malinovskaya TD, Najden EP, Shvalyov VI. Physico-Chemical Principles of Doping of Indium Oxide with Tin, Obtained by The Sol-Gel Method. Bulletin of the Tomsk Polytechnic University. 2004;307(1):93-98. (In Russ.).

17. Huang Z, Duan Y, Zhang Y. Electrohydrodynamic Direct-Writing for Flexible Electronic Manufacturing. Springer Singapore. 2018;(1):194. DOI: 10.1007/978-981-10-4759-6