Effects of Lithium Incorporation on the Morphological, Optical, and Sensing Properties of ZnO Thin Films Synthesized By Chemical Spray Pyrolysis
DOI:
https://doi.org/10.32628/IJSRSET251365Keywords:
ZnO, Li-doping, Thin Films, Chemical Spray Pyrolysis, XRD, AFM, Optical Properties, Band Gap, Gas Sensing, Nitrogen Dioxide (NO₂)Abstract
This research explores the effect of lithium (Li) doping on the structural, morphological, optical, and gas-sensing characteristics of zinc oxide (ZnO) thin films, which were deposited onto glass substrates using the chemical spray pyrolysis technique. X-ray diffraction (XRD) analysis revealed that all the films are polycrystalline in nature with a hexagonal wurtzite structure, exhibiting a preferred orientation along the (100) plane. Li incorporation induced a shift in diffraction peaks and significantly influenced microstructural parameters; the crystallite size increased to a maximum of 23.34 nm for the 4% Li-doped film, while dislocation density and microstrain decreased, indicating improved crystallinity. Atomic force microscopy (AFM) analysis showed that Li doping leads to a more uniform and compact surface morphology, accompanied by a reduction in both average particle size and surface roughness. Optical analysis revealed that Li doping induced a red shift in the absorption edge and reduced the optical band gap from 3.38 eV in pure ZnO to 3.25 eV in the 4% Li-doped film, an effect attributed to the introduction of defect states within the band gap. Furthermore, the gas sensing response to nitrogen dioxide (NO₂) was evaluated, with the highest doped film showing the lowest response, Li doping serves as an effective approach for tailoring the physical properties of ZnO.
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References
Chetan C. Singh, Emila Panda, Zinc interstitial threshold in Al-doped ZnO film: effect on microstructure and optoelectronic properties, J. Appl. Phys. 123 (2018) 165106. DOI: https://doi.org/10.1063/1.5021736
P. Bappaditya, D. Sarkar, P.K. Giri, Structural, optical, and magnetic properties of Ni doped ZnO nanoparticles: correlation of magnetic moment with defect density, Appl. Surf. Sci. 356 (2015) 804–811. DOI: https://doi.org/10.1016/j.apsusc.2015.08.163
A. B. Djurišić, A. M. C. Ng, X. Y. Chen, ZnO nanostructures for optoelectronics: material properties and device applications. Progress in quantum electronics, 34.4 (2010): 191-259. DOI: https://doi.org/10.1016/j.pquantelec.2010.04.001
A. B. Djurišić, Y. H. Leung, Optical properties of ZnO nanostructures. small, 2.8‐9 (2006): 944-961. DOI: https://doi.org/10.1002/smll.200600134
D. Li, Y. H. Leung, A. B. Djurišić, Z. T. Liu, M. H. Xie, et al., Different origins of visible luminescence in ZnO nanostructures fabricated by the chemical and evaporation methods. Applied Physics Letters, 85.9 (2004): 1601-1603. DOI: https://doi.org/10.1063/1.1786375
M. Wang, L. Jiang, E. J. Kim, S. H. Hahn, Electronic structure and optical properties of Zn(OH)2: LDA+U calculations and intense yellow luminescence, RSC Advances, 5.106 (2015): 87496-87503. DOI: https://doi.org/10.1039/C5RA17024A
M. Guezzoul, M. Bouslama, A.Ouerdane, et al., Chemical, morphological and optical properties of undoped and Cu-doped ZnO thin films submitted to UHV treatment. Applied Surface Science (2020): 146302. DOI: https://doi.org/10.1016/j.apsusc.2020.146302
Y. R. Denny, H. C. Shin, S. Seo, S. K. Oh, et al., Electronic and optical properties of hafnium indium zinc oxide thin film by XPS and REELS. Journal of Electron Spectroscopy and Related Phenomena, 185.1-2 (2012): 18-22. DOI: https://doi.org/10.1016/j.elspec.2011.12.004
G. C. Park, S. M. Hwang, J. H. Choi, Y. H. Kwon, et al., Effects of In or Ga doping on the growth behavior and optical properties of Zn O nanorods fabricated by hydrothermal process. physica status solidi (a), 210.8 (2013): 1552-1556. DOI: https://doi.org/10.1002/pssa.201200907
R. Lindsay, C. A. Muryn, E. Michelangeli, G. Thornton, ZnO (0001¯)–O surface structure: hydrogen-free (1× 1) termination. Surface science 565.2-3 (2004): L283-L287. DOI: https://doi.org/10.1016/j.susc.2004.07.014
A. Teke, Ü. Özgür, S. Doğan, X. Gu, H. Morkoç, B. Nemeth, et al, Excitonic fine structure and recombination dynamics in single-crystalline ZnO, Physical Review B, 70.19 (2004): 195207. DOI: https://doi.org/10.1103/PhysRevB.70.195207
P. Rong, S. Ren, Q. Yu, Fabrications and Applications of ZnO Nanomaterials in Flexible Functional Devices-A Review, Critical Reviews in Analytical Chemistry. 49.4 (2019) 336-349. DOI: https://doi.org/10.1080/10408347.2018.1531691
Hu G, Li SQ, Gong H, Zhao Y, Zhang J, Wijesinghe TLSL, et al., White light from an indium zinc oxide/ porous silicon light-emitting diode. J. Phys. Chem. C. 2009; 113: 751–754. DOI: https://doi.org/10.1021/jp808432f
S. Dutta, S. Chattopadhyay, A. Sarkar, M. Chakrabarti, D. Sanyal, D. Jana, Role of defects in tailoring structural, electrical and optical properties of ZnO. Progress in Materials Science, 54.1 (2009): 89-136. DOI: https://doi.org/10.1016/j.pmatsci.2008.07.002
J. A. Sans, J. F. Sánchez-Royo, A. Segura, G. Tobias, E. Canadell, Chemical effects on the optical band-gap of heavily doped ZnO: MIII (M= Al, Ga, In): an investigation by means of photoelectron spectroscopy, optical measurements under pressure, and band structure calculations. Physical Review B, B 79.19 (2009): 195105. DOI: https://doi.org/10.1103/PhysRevB.79.195105
A. Mang, K. Reimann, Band gaps, crystal-field splitting, spin-orbit coupling, and exciton binding energies in ZnO under hydrostatic pressure, Solid state communications, 94.4 (1995): 251-254. DOI: https://doi.org/10.1016/0038-1098(95)00054-2
C. Huang, M. Wang, Z. Deng, Y. Cao, et al., Low content indium-doped zinc oxide films with tunable work function fabricated through magnetron sputtering. Semiconductor science and technology, 25.4 (2010): 045008. DOI: https://doi.org/10.1088/0268-1242/25/4/045008
M. Girtan, M. Kompitsas, R. Mallet, I. Fasaki, On physical properties of undoped and Al and In doped zinc oxide films deposited on PET substrates by reactive pulsed laser deposition, The European Physical Journal-Applied Physics, 51.3 (2010). DOI: https://doi.org/10.1051/epjap/2010112
E. S. Babu & S. K. Hong, Effect of indium concentration on morphology of ZnO nanostructures grown by using CVD method and their application for H2 gas sensing, Superlattices and Microstructures, 82 (2015): 349-356. DOI: https://doi.org/10.1016/j.spmi.2015.02.029
K. U. Sim, S. W. Shin, A. V. Moholkar, J. H. Yun, J. H. Moon, J. H. Kim, Effects of dopant (Al, Ga, and In) on the characteristics of ZnO thin films prepared by RF magnetron sputtering system. Current Applied Physics, 10.3 (2010): S463-S467. DOI: https://doi.org/10.1016/j.cap.2010.02.028
K. Matsubara, P. Fons, K. Iwata, A. Yamada, K, et al., ZnO transparent conducting films deposited by pulsed laser deposition for solar cell applications. Thin Solid Films. 2003;431–432: 369–372. DOI: https://doi.org/10.1016/S0040-6090(03)00243-8
C. C. Hsu, C. C. Tsao, Y. H. Chen, X. Z. Zhang, Bipolar resistive switching characteristics of a sol-gel InZnO oxide semiconductor. Physica B: Condensed Matter 561 (2019): 64-69. DOI: https://doi.org/10.1016/j.physb.2019.02.048
R. Bel-Hadj-Tahar & A. B. Mohamed, Sol-gel processed indium-doped zinc oxide thin films and their electrical and optical properties, New Journal of Glass and Ceramics, 4.04 (2014): 55. DOI: https://doi.org/10.4236/njgc.2014.44008
A. Chakraborty, T. Mondal, S. K. Bera, S. K. Sen, R. Ghosh, G. K. Paul, Effects of aluminum and indium incorporation on the structural and optical properties of ZnO thin films synthesized by spray pyrolysis technique. Materials Chemistry and Physics, 112.1 (2008): 162-166. DOI: https://doi.org/10.1016/j.matchemphys.2008.05.047
G. Singh, S.B. Shrivastava, D. Jain, et al., Effect of indium doping on zinc oxide films prepared by chemical spray pyrolysis technique, Bull Mater Sci 33, 581–587 (2010). DOI: https://doi.org/10.1007/s12034-010-0089-6
S. R. Ardekani, A. S. R. Aghdam, M. Nazari, A. Bayat, E. Yazdani, E. Saievar-Iranizad, A comprehensive review on ultrasonic spray pyrolysis technique: Mechanism, main parameters and applications in condensed matter. Journal of Analytical and Applied Pyrolysis, (2019): 104631. DOI: https://doi.org/10.1016/j.jaap.2019.104631
C. Falcony, M. A. Aguilar-Frutis, M. García-Hipólito, Spray pyrolysis technique; high-K dielectric films and luminescent materials: a review. Micromachines, 9.8 (2018): 414. DOI: https://doi.org/10.3390/mi9080414
C. S. Hong, H. H. Park, J. Moon, H. H. Park, Effect of metal (Al, Ga, and In)-dopants and/or Ag-nanoparticles on the optical and electrical properties of ZnO thin films, Thin Solid Films 515.3 (2006): 957-960. DOI: https://doi.org/10.1016/j.tsf.2006.07.055
A. B. Djurišić, Y. H. Leung, K. H. Tam, Y. F. Hsu, et al., Defect emissions in ZnO nanostructures, Nanotechnology, 18.9 (2007): 095702. DOI: https://doi.org/10.1088/0957-4484/18/9/095702
K. H. Tam, C. K. Cheung, Y. H. Leung, A. B. Djurišić, C. C. Ling, et al., Defects in ZnO nanorods prepared by a hydrothermal method. The Journal of Physical Chemistry B, (2006): 20865-20871. DOI: https://doi.org/10.1021/jp063239w
F. Chang, S. Brahma, J. Huang, et al., Strong correlation between optical properties and mechanism in deficiency of normalized self-assembly ZnO nanorods. Sci Rep 9, 905 (2019). DOI: https://doi.org/10.1038/s41598-018-37601-8
Y. Xu, B. Bo, X. Gao, Z. Qiao, Passivation Effect on ZnO Films by SF6 Plasma Treatment, Crystals 9.5 (2019): 236. DOI: https://doi.org/10.3390/cryst9050236
C. H. Ahn, Y. Y. Kim, D. C. Kim, S. K. Mohanta, H. K. Cho, (2009). A comparative analysis of deep level emission in ZnO layers deposited by various methods. Journal of Applied Physics, 105.1 (2009): 013502. DOI: https://doi.org/10.1063/1.3054175
C. Chandrinou, N. Boukos, C. Stogios, , A.Travlos, PL study of oxygen defect formation in ZnO nanorods. Microelectronics journal, 40.2 (2009): 296-298. DOI: https://doi.org/10.1016/j.mejo.2008.07.024
J.F. Moulder, W.F. Stickle, P.E. Sobol, K.D. Bomben, Handbook of X-ray Photoelectron Spectroscopy. Physical Electronics Division, Perkin-Elmer Corporation, 1992.
K. Ramamoorthy, K. Kumar, R. Chandramohan, K. Sankaranarayanan, Review on material properties of IZO thin films useful as epi-n-TCOs in opto-electronic (SIS solarcells, polymeric LEDs) devices. Materials Science and Engineering: B 126.1 (2006): 1-15. DOI: https://doi.org/10.1016/j.mseb.2005.08.117
A. Singh, S. Chaudhary, D. K Pandya, High conductivity indium doped ZnO films by metal target reactive co-sputtering , Acta Materialia 111 (2016): 1-9. DOI: https://doi.org/10.1016/j.actamat.2016.03.012
M. Shaheera, K. G. Girija, M. Kaur, et al., Characterization and device application of indium doped ZnO homojunction prepared by RF magnetron sputtering, Optical Materials 101 (2020): 109723. DOI: https://doi.org/10.1016/j.optmat.2020.109723
S. Y. Lim, S. Brahma, C. P. Liu, R. C. Wang, J. L. Huang, Effect of indium concentration on luminescence and electrical properties of indium doped ZnO nanowires. Thin Solid Films 549 (2013): 165-171. DOI: https://doi.org/10.1016/j.tsf.2013.09.001
M. Caglar, S. Ilican, Y. Caglar, Influence of dopant concentration on the optical properties of ZnO: In films by sol–gel method. Thin Solid Films.
H. Zhang, W. Li, G. Qin, H. Ruan, Z. Huang, et al., Role of zinc interstitial defects in indium and magnesium codoped ZnO transparent conducting films. Applied Surface Science, 492 (2019): 392-398. DOI: https://doi.org/10.1016/j.apsusc.2019.06.245
S. Vempati, J. Mitra, P. Dawson, One-step synthesis of ZnO nanosheets: a blue-white fluorophore. Nanoscale research letters, 7.1 (2012): 470. DOI: https://doi.org/10.1186/1556-276X-7-470
A. Asok, A.R. Kulkarni, Mayuri N. Gandhi, Defect rich seed mediated growth: a novel synthesis method to enhance defect emission in nanocrystals, J. Mater. Chem. C 2 (2014) 1691–1697. DOI: https://doi.org/10.1039/C3TC32107J
F. Stavale, N. Nilius, H.J. Freund, STM Luminescence Spectroscopy of Intrinsic Defects in ZnO(0001̅) Thin Films. The Journal of Physical Chemistry Letters. (2013). 4.22. 3972-3976. DOI: https://doi.org/10.1021/jz401823c
A. B. Djurišić, X. Chen, Y. H. Leung, A. M. C. Ng, ZnO nanostructures: growth, properties and applications, Journal of Materials Chemistry, 22.14 (2012): 6526-6535. DOI: https://doi.org/10.1039/c2jm15548f
I. Shalish, H. Temkin, V. Narayanamurti, Size-dependent surface luminescence in ZnO nanowires. Physical Review B, 69.24 (2004): 245401. DOI: https://doi.org/10.1103/PhysRevB.69.245401
cathodoluminescence studies of stoichiometric and oxygen-deficient ZnO films. Applied Physics Letters, 78.16 (2001): 2285-2287. DOI: https://doi.org/10.1063/1.1361288
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