Physical properties of SnO2: Co thin films prepared by chemical spray pyrolysis

Areej Adnan Hateef1, Marwa Abdul Muhsien Hassan2,Najim A. Sumoom1, Sabah Jameel1

1 Iraqi Ministry of Sciences and Technology, 2  College of science, Al- Mustansiriyah University

     In this research, Co-doped SnO2 thin films were prepared by chemical spray pyrolysis technique using SnCl4.5H2O and CoCl2.6H2O, with impurity percentage are (0%-3%-6%-9%) on glass substrates preheated at (450oC) with spray rate 5sec./1min, and thickness (400nm). The investigation of (XRD) indicates that the (SnO2) films are polycrystalline type of (tetragonal), the optical properties and band gap energy was observed  and it`s found varied from (3.361-2.855 eV) when increasing in percentage  impurity the energy band gap decreased. The Hall coefficient, concentration and mobility of charge carriers of SnO2:Co films studied, and their results observed that the increase in impurity of cobalt caused increase in electrical properties generally. 
Keywords: thin films, SnO2, chemical spray pyrolysis, cobalt.

1-A.Gholizadeh, N.Tajabor, M.R.Alinejad, " Influence of N2- and Ar-ambient annealing on the physical properties of SnO2:Co  transparent  conducting films prepared by spray pyrolysis technique", "Iran journal of crystallography and mineralogy", Vol.  16, No. 4, Winter  1387/2009. 
2-S.Nicoletti, L.Dori, G.Cardinali, A.Parisini ,"Gas sensors for air quality monitoring: realization and characterization of undoped and noble  metal-doped SnO2 thin sensing films deposited by the pulsed laser ablation", "Sensors and Actuators B",  Vol.(60), 90-96, 1999. 
3-L.A.Patil, "Ultrasonically sprayed nanostructured SnO2 thin films for highly sensitive hydrogen sensing", ISBN 978-1-4398-  34015 Vol.(1),  2010. 
4-M. R. Alinejad,  M. Ghanaatshoar, M. M. Tehranchi, M. M. Bagheri Mohagheghi, S.M. Mohseni, "Magnetooptical Faraday  effect in Cobalt-  doped SnO2 transparent semiconducting films prepared by spray pyrolysis technique", Proceedings of the  Third Moscow International  Symposium on Magnetism (2005). 
5-S.B.Patil, P.P.Patil, M.A.More, "Acetone vapour sensing characteristics of cobalt-doped SnO2 thin films". "Sensors and  Actuators B", Vol.  (125), 126-130, 2007.  
6-V.Subramanian, J.C.Jiang, P.H.Smith and B.Rambabu, "Preparation of cobalt doped SnO2 nanorods and nanoparticles",  "Journal of  Nanoscience and Nanotechnol", Vol.(4), No.(125), 2004 
7-K.Y. Rajpure, et al., "Preparation and Properties of Fe-doped SnO2 Thin Films by Spray Pyrolysis Technique". "Journal of  Materials Chemistry  and Physics", Vol.(64),No.(184), 2000 
8-Yu, A.S. and R.Frech, "Coating of multi-walled carbon nanotube with SnO2  films of controlled thickness and its application  for Li-ion  battery", "Journal of Power Sources", Vol.(104), No.(97), 2002 
9-D. Perednis & L. J. Gauckler, Thin film deposition using spray pyrolysis, Journal of Electroceramics, 14, pp. 103 – 111,  (2005) 
10-E. Arca, K. Fleischer, and I. V. Shvets, Influence of the precursors and chemical composition of the solution on the  properties of zno thin  films grown by spray pyrolysis,  J. Phys. Chem. C 113, 21074–21081 (2009) 
11-D. R. Patil, L. A. Patil and D. P. Amalnerkar, Ethanol gas sensing properties of Al2O3doped ZnO thick film resistors, Bull.  Mater. Sci., Vol.  30, No. 6, pp. 553 – 559, (2007) 
12-N. Yamazoe, G. Sakai, and K. Shimanoe, Oxide semiconductor gas sensors, Catalysis Surveys from Asia Vol. 7, No. 1,  (2003) 
13-R. Savu, M. A. Ponce, E. Joanni, P. R. Bueno, M. Castro, M. Cilense, J. A. Varela, E. Longo, Grain size effect on the electrical response of  SnO2 thin and thick film gas sensors, Materials Research, Vol. 12, No. 1, 83-87, (2009) 
14-B.D.Cullity, "Elements of X-ray diffraction",(USA: Addison-Wesley Publishing Co.) 1956. 
15-V. Arivazhagan, S. Rajesh, Preparation of Nanocrystalline SnO2 thin films for Micro Gas Sensors, Journal of Ovonic  Research, Vol. 6, No. 5,  pp. 221-226, (2010) 
16-M. Boshta, F. Mahmoud, Characterization of Sprayed SnO2: Pd thin films for Gas Sensing Applications, Journal of Ovonic  Research, Vol. 6,  No. 2, pp. 93-98, (2010) 
17-M.H.Habibi, N.Talebian, "The Effect of Annealing on Structural, Optical and Electrical Properties of Nanostructured Tin    Doped Indium  Oxide Thin Films", "Acta Chim. Slov", Vol.(52), pp.53–59, 2005 
18-G.E.Patil, D.D.Kajale, D.N.Chavan, N.K.Pawar, P.T.Ahire, S.D.Shinde,V.B.Gaikwad, G.H.Jain, "Synthesis characterization and  gas sensing  performance of SnO2 thin films prepared by spray pyrolysis", "Bull. Mater. Sci.", Vol.(34), No.(1), pp. 1–9,  2011 
19-B. Zhang, Y. Tian, Structural, Optical, Electrical properties and FTIR studies of Fluorine doped SnO2 films Deposited by  Spray Pyrolysis, J.  Mater Sci., 46: 1884-1889, (2011) 
20-B. Zhang, Y. Tian, The FTIR studies of SnO2:Sb films Deposited by Spray Pyrolysis, Materials Letters 65, pp. 1204-1206,  (2011)