Effects of laser pulse energy on the structural, optical and electrical properties of pulsed laser deposited Ga-doped ZnO thin films
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Transparent conducting Ga-doped ZnO (GZO) thin films were deposited on glass substrate by pulsed laser deposition (PLD). The effects of laser pulse energy ranging from 80 to 200 mJ on microstructural, surface morphology, electrical and optical properties of GZO films were investigated in detail. XRD patterns have shown that all samples were hexagonal wurtzite structure presenting predominant orientation along the (002) c-axis direction, and the film obtained at 160 mJ showed the optimal crystallinity. The Raman spectra demonstrate that GZO films have oxygen vacancies, Zinc interstitials, and residual stress. The compact, homogenous and flat surface morphology of GZO films were observed by AFM. Hall effect measurements revealed that the electrical properties of samples were dominated largely by the crystallinity and the minimum resistivity of 6.10 × 10−4 Ω cm was obtained when GZO film grown at 160 mJ. Optical transmission spectra displayed an average transmittance higher than 90.6% for all GZO samples in the visible range. The film deposited at 160 mJ exhibited the maximum figure of merit of 22.70 × 10−3 Ω−1, owing to the low resistivity and high transmittance.
This work was financially supported by the National Natural Science Foundation of China (61474030), the Guangxi Natural Science Foundation (2015GXNSFAA139265), the Foundation of Guangxi Science & Technology Development Project (1598008-15) and the Foundation of Nanning Municipal Science & Technology Development Project (20151268).
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Conflict of interest
The authors declare that they have no conflict of interest.
- 3.A. Tomeda, T. Ishibe, T. Taniguchi, R. Okuhata, K. Watanabe, Y. Nakamura, Enhanced thermoelectric performance of Ga-doped ZnO film by controlling crystal quality for transparent thermoelectric films. Thin Solid Films 666, 185–190 (2018). https://doi.org/10.1016/j.tsf.2018.09.045 CrossRefGoogle Scholar
- 4.J. Chen, Y. Sun, X. Lv, D. Li, L. Fang, H. Wang, X. Sun, C. Huang, H. Yu, P. Feng, Preparation and characterization of high-transmittance AZO films using RF magnetron sputtering at room temperature. Appl. Surf. Sci. 317, 1000–1003 (2014). https://doi.org/10.1016/j.apsusc.2014.08.051 CrossRefGoogle Scholar
- 6.H. Chin, L. Chao, C. Wu, Crystal, optical, and electrical characteristics of transparent conducting gallium-doped zinc oxide films deposited on flexible polyethylene naphthalate substrates using radio frequency magnetron sputtering. Mater. Res. Bull. 79, 90–96 (2016). https://doi.org/10.1016/j.materresbull.2016.03.017 CrossRefGoogle Scholar
- 8.H. Kajii, Y. Mohri, H. Okui, M. Kondow, Y. Ohmori, Improved characteristics of conventional and inverted polymer photodetectors using phosphonic acid-based self-assembled monolayer treatment for interfacial engineering of Ga-doped ZnO electrodes. Jpn. J. Appl. Phys. 57, 03DA03 (2018). https://doi.org/10.7567/JJAP.57.03DA03 CrossRefGoogle Scholar
- 13.M.T. Ferdaous, S.A. Shahahmadi, M.M.I. Sapeli, P. Chelvanathan, M. Akhtaruzzaman, S.K. Tiong, N. Amin, Interplay between variable direct current sputtering deposition process parameters and properties of ZnO: Ga thin films. Thin Solid Films 660, 538–545 (2018). https://doi.org/10.1016/j.tsf.2018.06.005 CrossRefGoogle Scholar
- 18.R.S. Ajimsha, A.K. Das, P. Misra, M.P. Joshi, L.M. Kukreja, R. Kumar, T.K. Sharma, S.M. Oak, Observation of low resistivity and high mobility in Ga doped ZnO thin films grown by buffer assisted pulsed laser deposition. J. Alloys Compd. 638, 55–58 (2015). https://doi.org/10.1016/j.jallcom.2015.02.162 CrossRefGoogle Scholar
- 22.H. Mahdhi, S. Alaya, J.L. Gauffier, K. Djessas, Z.B. Ayadi, Influence of thickness on the structural, optical and electrical properties of Ga-doped ZnO thin films deposited by sputtering magnetron. J. Alloys Compd. 695, 697–703 (2017). https://doi.org/10.1016/j.jallcom.2016.11.117 CrossRefGoogle Scholar
- 23.S. Yu, W. Zhang, L. Li, H. Dong, D. Xu, Y. Jin, Structural, electrical, photoluminescence and optical properties of n-type conducting, phosphorus-doped ZnO thin films prepared by pulsed laser deposition. Appl. Surf. Sci. 298, 44–49 (2014). https://doi.org/10.1016/j.apsusc.2014.01.037 CrossRefGoogle Scholar
- 29.H.J. Al-Asedy, N. Bidin, K.N. Abbas, M.A. Al-Azawi, Structure, morphology and photoluminescence attributes of Al/Ga co-doped ZnO nanofilms: role of annealing time. Mater. Res. Bull. 97, 71–80 (2018). https://doi.org/10.1016/j.materresbull.2017.08.050 CrossRefGoogle Scholar
- 33.H. Chin, L. Chao, C. Wu, Crystal, optical, and electrical characteristics of transparent conducting gallium-doped zinc oxide films deposited on flexible polyethylene naphthalate substrates using radio frequency magnetron sputtering. Mater. Res. Bull. 79, 90–96 (2016). https://doi.org/10.1016/j.materresbull.2016.03.017 CrossRefGoogle Scholar
- 37.A.S. Pugalenthi, R. Balasundaraprabhu, V. Gunasekaran, N. Muthukumarasamy, S. Prasanna, S. Jayakumar, Effect of thickness on the structural, optical and electrical properties of RF magnetron sputtered GZO thin films. Mater. Sci. Semicond. Process. 29, 176–182 (2015). https://doi.org/10.1016/j.mssp.2014.02.014 CrossRefGoogle Scholar
- 38.K. Seo, H. Shin, J. Lee, K. Chung, H. Kim, The effects of thickness on the electrical, optical, structural and morphological properties of Al and Ga co-doped ZnO films grown by linear facing target sputtering. Vacuum 101, 250–256 (2014). https://doi.org/10.1016/j.vacuum.2013.09.009 CrossRefGoogle Scholar