Effect of Zinc and Copper co-doping for Cadmium Oxide thin films on NO2 and H2S gases sensitivity
DOI:
https://doi.org/10.24237/Keywords:
CdO, co-doping, AFM, FE-SEM, EDS, gas sensitivity, NO2, H2SAbstract
In this work, the Sol-gel spin coating process is used to synthesize pure and co-doping (Zn:Cu)% CdO thin films on glass substrates for use as gas sensors for NO2 and H2S. A range of characterization techniques are utilized to assess the structural, morphological, optical, electrical, and sensing properties of the prepared thin films. These techniques include X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), UV-vis measurements, Hall effect measurements, and sensitivity measurements. All films have a cubic crystal structure and are polycrystalline, according to XRD measurements. The co-doping ratio rose from 0% to 3%, resulting in an increase in the optical band gap values from 2.53 to 2.58 eV. AFM scans show that with co-doping, roughness and particle size gradually decrease. The form and size of the grains altered with the co-doping, according to FE-SEM analysis. EDS analysis additionally verified that O, Cd, Zn, and Cu were present in the original solution. All films have n-type charge carriers, according to Hall Effect tests, and higher co-doping ratios result in higher carrier concentrations and better conductivity. At different working temperatures, the sensitivity, responsiveness, and recovery time of the gas sensor were assessed. At 200 °C, pure and (3%Zn:3%Cu) co-doped CdO thin films showed optimal sensitivity of 45.9% and 129%, respectively, for the NO2 and H2S sensors.
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[1] A. Kumar, N. Sharma, A. P. Gutal, D. Kumar, P. Kumar, M. Paranjothy, M. Kumar, Growth and NO2 gas sensing mechanisms of vertically aligned 2D SnS2 flakes by CVD: Experimental and DFT studies, Sensors and Actuators B: Chemical, 353, 131078(2022), DOI(https://doi.org/10.1016/j.snb.2021.131078)
[2] T. Seiyama, A. Kato, K. Fujiishi, M. Nagatani, A new detector for gaseous components using semiconductive thin films, Analytical Chemistry, 34(11), 1502-1503(1962)
[3] S. K. Pandey, K. H. Kim, K. T. Tang, A review of sensor-based methods for monitoring hydrogen sulfide, TrAC Trends in Analytical Chemistry, 32, 87-99(2012), DOI(https://doi.org/10.1016/j.trac.2011.08.008)
[4] E. Ashori, F. Nazari, F. Illas, Adsorption of H2S on carbonaceous materials of different dimensionality, International Journal of Hydrogen Energy, 39(12), 6610-6619(2014), DOI(https://doi.org/10.1080/10962247.2018.1536004)
[5] N. Barsan, M. Schweizer-Berberich, W. Göpel, Fundamental and practical aspects in the design of nanoscaled SnO2 gas sensors: a status report, Fresenius' journal of analytical chemistry, 365, 287-304(1999), DOI(https://doi.org/10.1007/s002160051490)
[6] G. F. Fine, L. M. Cavanagh, A. Afonja, R. Binions, Metal oxide semi-conductor gas sensors in environmental monitoring, Sensors, 10(6), 5469-5502(2010), DOI(https://doi.org/10.3390/s100605469)
[7] J. Zhang, Z. Qin, D. Zeng, C. Xie, Metal-oxide-semiconductor based gas sensors: screening, preparation, and integration, Physical Chemistry Chemical Physics, 19(9), 6313-6329(2017), DOI(https://doi.org/10.1039/C6CP07799D)
[8] X. Liu, S. Cheng, H. Liu, S. Hu, D. Zhang, H. Ning, A survey on gas sensing technology, Sensors, 12(7), 9635-9665(2012), DOI(https://doi.org/10.3390/s120709635)
[9] S. P. Lee, Electrodes for semiconductor gas sensors, Sensors, 17(4), 683(2017), DOI(https://doi.org/10.3390/s17040683)
[10] C. R. Bobade, Cadmium oxide thin films synthesized at low temperature by spray CVD technique for H2S gas sensing applications, I J R B A T, Issue (VI), Vol. II, 118-125(2018)
[11] B. Şahin, Dual doping (Cu with rare-earth element Ce): An effective method to enhance the main physical properties of CdO films, Superlattices and Microstructures, 136, 106296(2019), DOI(https://doi.org/10.1016/j.spmi.2019.106296)
[12] B. R. Kumar, K. H. Prasad, K. Kasirajan, M. Karunakaran, V. Ganesh, Y. Bitla, I. S. Yahia, Enhancing the properties of CdO thin films by co-doping with Mn and Fe for photodetector applications, Sensors and Actuators A: Physical, 319, 112544(2021), DOI(https://doi.org/10.1016/j.sna.2021.112544)
[13] M. Ravikumar, R. Chandramohan, K. D. A. Kumar, S. Valanarasu, V. Ganesh, M. Shkir, A. Kathalingam, Effect of Nd doping on structural and opto-electronic properties of CdO thin films fabricated by a perfume atomizer spray method, Bulletin of Materials Science, 42, 1-10(2019), DOI(https://doi.org/10.1007/s12034-018-1688-x)
[14] M. Shkir, V. Ganesh, S. AlFaify, I. S. Yahia, H. Y. Zahran, Tailoring the linear and nonlinear optical properties of NiO thin films through Cr 3+ doping, Journal of Materials Science: Materials in Electronics, 29, 6446-6457(2018), DOI(https://doi.org/10.1007/s10854-018-8626-y)
[15] S. Valanarasu, V. Dhanasekaran, M. Karunakaran, T. A. Vijayan, R. Chandramohan, T. Mahalingam, Microstructural, optical and electrical properties of various time annealed spin coated MgO thin films, Journal of Materials Science: Materials in Electronics, 25, 3846-3853(2014), DOI(https://doi.org/10.1007/s10854-014-2098-5)
[16] K. S. Mohammed, J. M. Mansoor, J. Alzanganawee, S. Iftimie, , An investigation of annealing and (Zn+ Co) co-loading impact on certain physical features of nano-structured (CdO) thin films coated by a sol-gel spin coating process, Journal of Ovonic Research, 17(5), (2021), DOI(https://doi.org/10.15251/JOR.2021.175.447)
[17] H. Kim, J. S. Horwitz, G. P. Kushto, S. B. Qadri, Z. H. Kafafi, D. B. Chrisey, Transparent conducting Zr-doped In2O3 thin films for organic light-emitting diodes, Applied Physics Letters, 78(8), 1050-1052(2001), DOI(https://doi.org/10.1063/1.1350595)
[18] M. K. Khalaf, B. A. ALhilli, A. I. Khudiar, A. Abd Alzahra, Influence of nanocrystalline size on optical band gap in CdSe thin films prepared by DC sputtering, Photonics and Nanostructures-Fundamentals and Applications, 18, 59-66(2016), DOI(https://doi.org/10.1016/j.photonics.2016.01.001)
[19] K. A. Aadim, A. H. Khidhir, Effect of Zinc (Zn)-Doped on the Structural, Optical and Electrical Properties of (Cdo) 1-Xznx Films Prepared by Pulsed Laser Deposition Technique, Iraqi Journal of Physics, 19(51), 64-71(2021), DOI(https://doi.org/10.30723/ijp.v19i51.676)
[20] M. Anitha, N. Anitha, K. Saravanakumar, I. Kulandaisamy, L. Amalraj, Effect of Zn doping on structural, morphological, optical and electrical properties of nebulized spray-deposited CdO thin films, Applied Physics A, 124, 1-13(2018), DOI(https://doi.org/10.1007/s00339-018-1993-7)
[21] T. Noorunnisha, M. Suganya, M. Karthika, C. Kayathiri, K. Usharani, S. Balamurugan, A. R. Balu, (Zn+ Co) co-doped CdO thin films with improved figure of merit values and ferromagnetic orderings with low squareness ratio well suited for optoelectronic devices and soft magnetic materials applications, Applied Physics A, 126, 1-9(2020), DOI(https://doi.org/10.1007/s00339-020-03954-z)
[22] A. Eskandari, F. Jamali-Sheini, Sonochemical synthesis of Cu-doped CdO nanostructures and investigation of their physical properties, Materials Science in Semiconductor Processing, 74, 210-217(2018), DOI(https://doi.org/10.1016/j.mssp.2017.08.028)
[23] A. H. K. Elttayef, H. M. Ajeel, A. I. Khudiar, Effect of annealing temperature and doping with Cu on physical properties of cadmium oxide thin films, Journal of Materials Research and Technology, 2(2), 182-187(2013), DOI(https://doi.org/10.1016/j.jmrt.2013.02.004)
[24] K. Usharani, A. R. Balu, Properties of spray deposited Zn, Mg incorporated CdO thin films, Journal of Materials Science: Materials in Electronics, 27, 2071-2078(2016), DOI(https://doi.org/10.1007/s10854-015-3993-0)
[25] G. Selvan, M. P. Abubacker, A. R. Balu, Structural, optical and electrical properties of Cl-doped ternary CdZnS thin films towards optoelectronic applications, Optik, 127(12), 4943-4947(2016), DOI(https://doi.org/10.1007/s10854-015-3993-0)
[26] S. Jin, Y. Yang, J. E. Medvedeva, J. R. Ireland, A. W. Metz, J. Ni, T. J. Marks, Dopant ion size and electronic structure effects on transparent conducting oxides Sc-doped CdO thin films grown by MOCVD, Journal of the American Chemical Society, 126(42), 13787-13793(2004), DOI(https://doi.org/10.1021/ja0467925)
[27] Bel-Hadj-Tahar, R., & Mohamed, A. B., Sol-gel processed indium-doped zinc oxide thin films and their electrical and optical properties, New Journal of Glass and Ceramics, 4(4), 55-65(2014), DOI(https://doi.org/10.4236/njgc.2014.44008)
[28] A. Staerz, U. Weimar, N. Barsan, Current state of knowledge on the metal oxide based gas sensing mechanism, Sensors and Actuators B: Chemical, 358, 131531(2022), DOI(https://doi.org/10.1016/j.snb.2022.131531)
[29] J. C. Hsieh, C. J. Liu, Y. H. Ju, Response characteristics of lead phthalocyanine gas sensor: effects of film thickness and crystal morphology, Thin Solid Films, 322(1-2), 98-103(1998), DOI(https://doi.org/10.1016/S0040-6090(97)00964-4)
[30] L. A. Patil, A. R. Bari, M. D. Shinde, V. V. Deo, D. P. Amalnerkar, Synthesis of ZnO nanocrystalline powder from ultrasonic atomization technique, characterization, and its application in gas sensing, IEEE Sensors journal, 11(4), 939-946(2010), DOI(https://doi.org/10.1109/JSEN.2010.2066265)
[31] L. Fan, X. Yang, H. Sun, A novel flexible sensor for double-parameter decoupling measurement of temperature and pressure with high sensitivity and wide range, Journal of Materials Chemistry C, 11(30), 10163-10177(2023), DOI(https://doi.org/10.1039/D3TC01636F)
[32] F. Challali, D. Mendil, T. Touam, T. Chauveau, V. Bockelée, A. G. Sanchez, M. P. Besland, Effect of RF sputtering power and vacuum annealing on the properties of AZO thin films prepared from ceramic target in confocal configuration, Materials Science in Semiconductor Processing, 118, 105217(2020), DOI(https://doi.org/10.1016/j.mssp.2020.105217)
[33] R. Tanuma, H. Haga, M. Sugiyama, Influence of carrier mobility on sensitivity of room-temperature-operation CO2 sensor based on SnO2 thin film, Japanese Journal of Applied Physics, 57(11), 115503(2018), DOI(https://doi.org/10.35848/1347-4065/ad358e)
[34] N. K. Abbas, I. M. Ibrahim, M. A. Saleh, Characteristics of MEH-PPV/Si and MEH-PPV/PS heterojunctions as NO2 gas sensors, Silicon, 10, 1345-1350(2018), DOI(https://doi.org/10.1007/s12633-017-9610-5)
[35] S. Pagidi, K. S. Pasupuleti, M. Reddeppa, S. Ahn, Y. Kim, J. H. Kim, M. Y. Jeon, Resistive type NO2 gas sensing in polymer-dispersed liquid crystals with functionalized-carbon nanotubes dopant at room temperature, Sensors and Actuators B: Chemical, 370, 132482(2022), DOI(https://doi.org/10.1016/j.snb.2022.132482)
[36] M. K. Khalaf, B. T. Chiad, A. F. Ahmed, F. A. Mutlak, Thin film technique for preparing nano-ZnO gas sensing (O2, NO2) using Plasma Deposition, Int. J. Appl. Innov. Eng. Manag, 2, 178-184(2013)
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