Nanocrystalline CuO Thin Films for H₂S Monitoring: Microstructural and Optoelectronic Characterization

Vikas Patil, Datta Jundale, Shailesh Pawar, Manik Chougule, Prsad Godse, Sanjay Patil, Bharat Raut, Shashwati Sen

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DOI: 10.4236/jst.2011.12006                

Abstract

Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H₂S sensors. The dependence of the H₂S response on the operating temperature, H₂S concentration of CuO film (annealed at 700^。C) was investigated. The CuO film showed selectivity for H₂S. The maximum H₂S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200^oC was achieved.

Keywords

CuO Thin Films, Structural Properties, Optoelectronic Properties, H₂S Sensor

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	O. Wurzinger and G. Reinhardt, “CO-Sensing Properties of Doped SnO2 Sensors in H2-Rich Gases,” Sensors and Actuators B, Vol. 103, No. 1-2, 2004, pp. 104-110. doi:10.1016/j.snb.2004.04.041
[2]	J. Zheng, W. Xiaojuan, Z. Bing, G. Huijiao, L. Tiebing and W. Minghong, “Effects of Electron Beam Irradiation on Tin Dioxide Gas Sensors,” Bulletin of Materials Science, Vol. 31 No. 1, 2008, pp. 83-86. doi:10.1007/s12034-008-0014-4
[3]	A. Chaturvedi, V. N. Mishra, R. Dwivedi and S. K. Srivastava, “Selectivity and Sensitivity Studies on Plasma Treated Thick Film Tin Oxide Gas Sensors,” Microelectronics Journal, Vol. 31 No. 4, 2000, pp. 283-290. doi:10.1016/S0026-2692(99)00147-0
[4]	E. Comini, A. Cristalli, G. Faglia and G. Sberveglieri, “Light Enhanced Gas Sensing Properties of Indium Oxide and Tin Dioxide Sensors,” Sensors and Actuators B, Vol. 65, No. 1-3, 2000, pp. 260-263. doi:10.1016/S0925-4005(99)00350-0
[5]	X. Q. Liu, S. W. Tao and Y. S. Shen, “Preparation and Characterization of Nanocrystalline α-Fe2O3 by a Sol–Gel Process,” Sensors and Actuators B, Vol. 40 No. 2-3, 1997, pp. 161-165. doi:10.1016/S0925-4005(97)80256-0
[6]	Y. Zhu, H. Lu, Y. Lu and X. Pan, “Characterization of SnO2 Films Deposited by d.c. Gas Discharge Activating Reaction Evaporation onto Amorphous and Crystallinesubstrates,” Thin Solid Films, Vol. 224, No. 1, 1993, pp. 82-86. doi:10.1016/0040-6090(93)90462-X
[7]	C. C. Chai, J. Peng and B. P. Yan, “Preparation and Gas-Sensing Properties of αFe2O3thin Films,” Journal of Electronic Materials, Vol. 24 No. 7, 1995, pp. 799-804. doi:10.1007/BF02653327
[8]	B. Balamurugan and B. R. Mehta, “Nanocrystalline Thin Films, Optical Properties. Structural Properties. X-Ray Diffraction,” Thin Solid Films, Vol. 396, No. 1-2, 2001, pp. 90-96. doi:10.1016/S0040-6090(01)01216-0
[9]	F. Marabelli, G. B. Parraviciny and F. S. Orioli, “Optical Gap of CuO,” Physical Review B, Vol. 52, No. 3, 1995, pp. 1433-1436. doi:10.1103/PhysRevB.52.1433
[10]	J. Ghijsen, L. H. Tjeng, J. V. Elp, H. Eskes, J. Westerink, G. A. Sawatzky and M. T. Czyzyk, “Electronic Structure of Cu2O and CuO,” Physical Review B, Vol. 38, No. 16, 1988, pp. 11322-11330. doi:10.1103/PhysRevB.38.11322
[11]	J. R. Oritz, T. Ogura, J. Medina-Valtierra, S. E. Acosta-Ortiz, P. Bosh, J. A. de las Reyes and V. H. Lara, “A Catalytic App.lication of Cu2O and CuO Films Deposited over Fiberglass,” App.lied Surface Science, Vol. 174, No. 3-4, 2001, pp. 177-184.
[12]	R. Zhou, T. Yu, X. Jiang, F. Chen and X. Zheng, “Temperature-Programmed Reduction and Temperature-Pro- grammed Desorption Studies of CuO/ZrO2 Catalysts,” App.lied Surface Science, Vol. 148, No. 3-4, 1999, pp. 263-270. doi:10.1016/S0169-4332(98)00369-9
[13]	S. Saito, M. Miyayama, K. Kaumoto and H. Yanagida, “Gas Sensing Characteristics of Porous ZnO and Pt/ZnO Ceramics,” Journal of the American Ceramic Society, Vol. 68, No. 1, 1985, pp. 40-43. doi:10.1111/j.1151-2916.1985.tb15248.x
[14]	E. Traversa, “New Ceramic Materials for Chemical Sensors,” Journal of Intelligent Material Systems and Structures, Vol. 6, No. 6, 1995, pp. 860-869. doi:10.1177/1045389X9500600615
[15]	J. S. Cruz, G. T. Delgado, R. C. Perez, S. J. Sandoval, O. J. Sandoval, C. I. Z. Romero, J. M. Marin and O. Z. Angel, “Dependence of Electrical and Optical Properties of Sol–Gel Prepared Undoped Cadmium Oxide Thin Films on Annealing Temperature,” Thin Solid Films, Vol. 493 No. 1-2, 2005, pp. 83-87. doi:10.1016/j.tsf.2005.07.237
[16]	R. Das and S. Ray, “Zinc oxide a transparent, conducting IR-reflector prepared by rf-magnetron sputtering,” J. Phys. D: App.l. Phys, Vol. 36 (2003, pp. 152-155. doi:10.1088/0022-3727/36/2/312
[17]	Y. Zhang, G. Du, X. Yang, B. Zhao, Y. Ma, T. Yang, H. C. Ong, D. Liu and S. Yang, “Effect of Annealing on ZnO Thin Films Grown on (001) Silicon Substrate by Low-Pressure Metalorganic Chemical Vapour Deposition,” Semiconductor Science and Technology, Vol. 19, No. 6, 2004, pp. 755-758. doi:10.1088/0268-1242/19/6/017
[18]	S. L. Patil, S. G. Pawar, A. T. Mane M. A. Chougule and V. B. Patil, “Nanocrystalline ZnO Thin Films: Optoelectronic and Gas Sensing Properties,” Journal of Materials Science Materials in Electronics, Vol. 21, No. 12, 2010, pp. 1332-1336. doi:10.1007/s10854-010-0071-5
[19]	S. T. Shishiyanu, T. S. Shishiyanu and O. I. Lupan, “Novel NO2 Gas Sensor Based on Cuprous Oxide Thin Films,” Sensors and Actuators B, Vol. 113 No. 1, 2006, pp. 468-476.
[20]	J. H. Yu and G. M. Choi, “Selective CO Gas Detection of CuO- and ZnO Doped SnO2 Gas Sensor,” Sensors and Actuators B, Vol. 75 No. 1-2, 2001, pp. 56-61. doi:10.1016/S0925-4005(00)00742-5
[21]	P. Mitra, J. Physical Sciences, 14, 2010, pp. 235-240.
[22]	J. Morales, L. Sanchez, F. Martin, J. R. Ramos-Barrado and M. Sanchez, Thin Solid Films, 474, 205, pp. 133-140.
[23]	L. Armelao, D. Barreca, M. Bertapp.elle, G. Boltaro, C. Sada and E. Tondello, “A Sol-Gel App.roach to Nanophasic Copp.er Oxide Thin Films,” Thin Solid Films, Vol. 442, No. 1-2, 2003, pp. 48-52. doi:10.1016/S0040-6090(03)00940-4
[24]	K. H. Yoon, W. J. Choi and D. H. Kang, “Photoelectrochemical Properties of Copp.er Oxide Thin Films Coated on an n-Si Substrate,” Thin Solid Films, Vol. 372, No. 1-2, 2000, pp. 250-256. doi:10.1016/S0040-6090(00)01058-0
[25]	V. Gupta and A. Mansingh, “Influence of Post-Deposi- tion Annealing on the Structural and Optical Properties of Sputtered Zinc Oxide Film,” Journal of Applied Physics, Vol. 80, No. 2, 1996, pp. 1063-1073. doi:10.1063/1.362842
[26]	P. K. Ghosh, R. Maity and K. K. Chattopadhyay, “Electrical and Optical Properties of Highly Conducting CdO: F Thin Film Deposited by Sol-Gel Dip Coating Technique,” Solar Energy Materials and Solar Cells, Vol. 81, No. 2, 2004, pp. 279-289. doi:10.1016/j.solmat.2003.11.021
[27]	K. Gurumurugan, D. Mangalaraj, S. K. Narayandass and Y. Nakanishi, “DC Reactive Magnetron Sputtered CdO Thin Films,” Materials Letters, Vol. 28, No. 4-6, 1996, pp. 307-312. doi:10.1016/0167-577X(96)00074-2
[28]	M. Ghosh and C. N. R. Rao, “Solvothermal Synthesis of CdO and CuO Nanocrystals,” Chemical Physics Letters, Vol. 393, No. 4-6, 2004, pp. 493-497. doi:10.1016/j.cplett.2004.06.092
[29]	S. G. Pawar, S. L. Patil, M. A. Chougule and V. B. Patil, “Synthesis and Characterization of Nanocrystalline TiO2 Thin Films,” Journal of Materials Science: Materials in Electronics, Vol. 22, No. 3, 2011, pp. 260-264. doi:10.1007/s10854-010-0125-8
[30]	Y. K. Jeong and G. M. Choi, “Nonstoichiometry and Electrical Conduction of CuO,” Journal of Physics and Chemistry of Solids, Vol. 57, No. 1, 1996, pp. 81-84. doi:10.1016/0022-3697(95)00130-1
[31]	J. H. Lee, K. H. Ko and B. O. Park, “Electrical and Optical Properties of ZnO Transparent Conducting Films by the Sol–Gel Method,” Journal of Crystal Growth, Vol. 247, No. 1-2, 2003, pp. 119-125. doi:10.1016/S0022-0248(02)01907-3
[32]	R. Hong, et al., “Influence of Different Post-Treatments on the Structure and Optical Properties of Zinc Oxide Thin Films” App.lied Surface Science, Vol. 242, No. 3-4, 2005, pp. 346-352. doi:10.1016/j.apsusc.2004.08.037
[33]	A. M. Chaparro, et al., “SnO2 Substrate Effects on the Morphology and Composition of Chemical Bath Deposited ZnSe Thin Films,” Thin Solid Films, Vol. 361-362, 2000, pp. 177-182. doi:10.1016/S0040-6090(99)00791-9
[34]	D. H. Bao, et al., “Band-Gap Energies of Sol-Gel-De- rived SrTiO3 Thin Films,” App.lied Physics Letters, Vol. 79, No. 23, 2001, pp. 3767-3772. doi:10.1063/1.1423788
[35]	M. Mabrook and P. Hawkins, “A Rapidly-Responding Sensor for Benzene, Methanol and Ethanol Vapours Based on Films of Titanium Dioxide Dispersed in a Polymer Operating at Room Temperature,” Sensors and Actuators B: Chemical, Vol. 75, No. 3, 2001, pp. 197-202. doi:10.1016/S0925-4005(01)00761-4
[36]	G. Martinelli, M. C. Carotta, M. Ferroni, Y. Sadaoka and E. Traversa, “Screen-Printed Perovskite-Type Thick Films as Gas Sensors for Environmental Monitoring,” Sensors and Actuators B: Chemical, Vol. 55, No. 2-3, 1999, pp. 99-110. doi:10.1016/S0925-4005(99)00054-4
[37]	Y. Wang, J. Chen and X. Wu, “Preparation and Gas- Sensing Properties of Perovskite-Type SrFeO3 Oxide,” Materials Letters, Vol. 49, No. 6, 2001, pp. 361-364.