[01] R. V. Vidap, Department of Electronic Science, Modern College of Arts, Science & Commerce, Pune, MS, India. [02] S. S. Bandgar, Department of Electronics, DBF Dayanand College of Arts & Science, Solapur, MS, India. [03] G. S. Shahane, Department of Electronics, DBF Dayanand College of Arts & Science, Solapur, MS, India.

A sol-gel spin coating method has been successfully used to synthesize Al-doped ZnO thin films. The XRD studies show synthesis of phase pure ZnO thin films with hexagonal wurtzite structure. The lattice parameters are a=3.2568Å and c=5.2108Å. Al-doping enhances the preferential growth along (002) direction. The lattice parameters decrease with increase in Al-doping concentration. SEM studies show that with Al-doping the growth of the films takes place with porous structure embedded with nanogranules overgrown on the folded structure. This indicates that Al-doping has an influence on the surface morphology of the films. AFM studies show that the maximum surface roughness of the film increases with Al-doping concentration. Optical study revealed that band gap of ZnO is 3.25 eV with direct band to band transitions and decreases with Al-doping concentration. The properties of ZnO thin films can be effectively tailored with Al-doping. These synthesized Al-doped ZnO thin films can be effectively used in photocatalysis and gas sensor applications.

Zinc Oxide Thin Films, Structural Characterization, Optical Properties

[01] M. Jun, S. Park and J. Koh, “Comparative studies of Al-doped ZnO and Ga-doped ZnO transparent conducting oxide thin films”. Nanoscale Res. Lett., 7 (2012) 639. [02] O. Lupan, S. Shishiyanu, V. Ursaki, H. Khallaf, L. Chow, T. Shishiyanu, V. Sontea, E. Monaico and S. Railean, “Synthesis of nanostructured Al-doped zinc oxide films on Si for solar cell applications”. Sol. Ener. Mater. Sol. Cells, 93 (2009) 1417-1422. [03] A. R. Marlinda, N. M. Huang, M. R. Muhamad, M. N. An'amt, B.Y.S. Chang, N. Yusoff, I. Harrison, H. N. Lim, C. H. Chia, S. Vijay Kumar, “Highly efficient preparation of ZnO nanorods decorated reduced grapheme oxide nanocomposites”. Materials Letters 80 (2012) 9-12. [04] J. Lv, C. Liu, W. Gong, Z. Zi, X. Chen, K. Huang, T. Wang, G. He, X. Song, Z. Sun, “Effect of solution concentrations on crystal structure, surface topographies and photoluminescence properties of ZnO thin films”. Superlattices and Microstructures, 51 (2012) 886-892. [05] Y. Liu, T. Hang, Y. Xie, Z. Bao, J. Song, H. Zhang, E. Xie, “Effect of Mg doping on the hydrogen-sensing characteristics of ZnO thin films”. Sensors and Actuators B, 160 (2011) 266-270. [06] M. Gupta, V. Sharma, J. Shrivastava, A. Solanki, A. P. Singh, V. R. Satsangi, S. Dass and R. Shrivastav, “Preparation and characterization of nanostructured ZnO thin films for photoelectrochemical splitting of water”. Bull. Mater. Sci., 32(1) (2009) 23-30. [07] S. D. Shinde, G. E. Patil, D. D. Kajale, V. B. Gaikwad, G. H. Jain, “Synthesis of ZnO nanorods by spray pyrolysis for H2S gas sensor”. Journal of Alloys and Compounds, 528 (2012) 109-114. [08] P. Sagar, M. Kumar and R. M. Mehra, “Electrical and optical properties of sol-gel derived ZnO-Al thin films”. Materials Science-Poland, 23(3) (2005) 685-696. [09] R. V. Vidap, V. L. Mathe and G. S. Shahane, “Structural, Optical and Gas Sensing Properties of Spin Coated Nanocrystalline Zinc Oxide Thin Films”. J. Mater. Sci.: Mater. Electron., 24(9) (2013) 3170 - 3174. [10] G. M. Wu, Y. F. Chen and H. C. Lu, “Aluminum-Doped Zinc Oxide Thin Films Prepared by Sol-Gel and RF Magnetron Sputtering”. Acta Physica Polonica A, 120(1) (2011) 149-152. [11] J. K. Seo, K. Ko, H. J. Cho, W. S. Chi, M. Park, K. Seo, Y. Park and D. Lim, “Synthesis and Characterization of Al-Doped Zinc Oxide Thin Films by an Radio Frequency Magnetron Sputtering Method for Transparent Electrode Applications”. Trans. Elect. Electron. Mater., 11(1) (2010) 29-32. [12] S. Mondal, S. Bhattacharyya and P. Mitra, “Effect of Al doping on microstructure and optical band gap of ZnO thin film synthesized by successive ion layer adsorption and reaction”. Pramana, 80(2) (2013) 315. [13] L. C. Nehru, V. Swaminathan, C. Sanjeeviraj, “Rapid synthesis of nanocrystalline ZnO by a microwave-assisted combustion method”. Powder Technology, 226 (2012) 29-33. [14] J. Xu, Y. Yu, X. He, J. Sun, F. Liu, G. Lu, “Synthesis of hierarchical ZnO orientation-ordered film by chemical bath deposition and its gas sensing properties”. Materials Letters. 81 (2012) 145-147. [15] A. U. Ubale and V. P. Deshpande, “Effect of manganese inclusion on structural, optical and electrical properties of ZnO thin films”. J. Alloys and Compounds, 500 (2010) 138-143. [16] R. Bhargava, P.K. Sharma, A.K. Chawala, S. Kumar, R. Chandra, A. C. pandey and N. Kumar, “Variation in structural, optical and magnetic properties of Zn1-xCrxO (x=0.0, 0.10, 0.15 and 0.20) nanoparticles: Role of dopant concentration on non-saturation of magnetization”. Mat. Chem. Phys., 125 (2011) 664-671. [17] M. M. Rahman, M. K. R. Khan, M. R. Islam, M. A. Halim, M. Shahjahan, M. A. Hakim, D. K. Saha and J. U. Khan, “Effect of Al Doping on Structural, Electrical, Optical and Photoluminescence Properties of Nano-Structural ZnO Thin Films”. J. Mater. Sci. Technol., 28(4) (2012) 329-335. [18] G. S. Shahane, B. M. More, C. B. Rotti and L. P. Deshmukh, Studies on chemically deposited CdS1-xSex mixed thin films”. Mat. Chem. Phys. 47 (1997) 263-267. [19] L. P. Deshmukh, C. B. Rotti, K. M. Garadkar, P. P. Hankare, B. M. More and G. S. Shahane, “Structural and optical properties of Cd_1-xZn_xS mixed thin films”. Ind. J. Pure & Appl. Phys., 35 (1997) 428-431. [20] P. Yao, S. Hang and M. Wu, “Growth characteristics and properties of Al-doped ZnO thin films by DC magnetron sputtering from AZOY target”. Trans. Canad. Soc. Mech. Eng., 37(3) (2013) 303-312. [21] S. P. Shrestha, R. Ghimire, J. J. Nakarmi, Y. S. Kim, S. Shrestha, C. Y. Park and J. H. Boo, “Properties of ZnO: Al Films Prepared by Spin Coating of Aged Precursor Solution”. Bull. Korean Chem. Soc., 31(1) (2010) 112-115.