VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY LE THI HIEN UNDOPED AND DOPED ZNO – BASED THIN FILMS BY A SOLUTION PROCESS: PREPARATION AND CHARACTERIZATION MASTER’S THESIS Ha Noi, 2019 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY LE THI HIEN UNDOPED AND DOPED ZNO – BASED THIN FILMS BY A SOLUTION PROCESS: PREPARATION AND CHARACTERIZATION MAJOR: NANOTECHNOLOGY CODE: PILOT SUPERVISOR: Senior lecturer Dr Bui Nguyen Quoc Trinh Ha Noi, 2019 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com ACKNOWLEDGMENTS First of all, I would like to send special thanks to my supervisor, Dr Bui Nguyen Quoc Trinh, a Senior Lecturer at University of Engineering and Technology and Vietnam Japan University, Vietnam National University in Hanoi, for supporting a great academic environment, helpful advices and strong motivations, which should be an inspiration for me, now and future He always encourages me in doing experiments, in thinking physical meanings independently, and in writing the thesis Second, apart from my supervisor in Vietnam, I am grateful to Prof Akihiko Fujiwara at Department of Nanotechnology for Sustainable Energy, Kwansei Gakuin University in Japan, for his unforgettable supports to my internship program Also, I am thankful to MSc Nguyen Quang Hoa at VNU Hanoi University of Science for X-ray diffractormeter measurement and scanning electron microscope observation Third, I would like to thank all faculty members of Nanotechnology Program, Vietnam Japan University, Vietnam National University for teaching and helping me within 2-year master course Last but not least, my profound gratitude would be expressed to my parents, sisters, brother, and friends, because of their unconditional loves when facing difficulties in completion of master degree and whole life This thesis is supported by the research project in 2019 from Vietnam Japan University (VJU), Research Grant Program of Japan International Cooperation Agency (JICA), and the project No QG.19.02 of Vietnam National University, Hanoi i LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com TABLE OF CONTENTS ACKNOWLEDGMENTS i TABLE OF CONTENTS ii LIST OF FIGURES v LIST OF TABLES vii LIST OF ABBREVIATIONS viii ABSTRACT INTRODUCTION .2 CHAPTER LITERATURE REVIEW 1.1 Overview of ZnO material 1.1.1 Crystal structure 1.1.1.1 Wurtzite structure .6 1.1.1.2 Zinc blende structure 1.1.1.3 NaCl structure (Rocksalt) 1.1.2 Energy bandgap structure of ZnO 1.1.3 Properties of Zinc Oxide 1.1.3.1 Electrical property 1.1.3.2 Optical properties 1.2 Techniques of thin films preparation 10 1.2.1 Vacuum processes 10 1.2.1.1 Sputtering method 10 1.2.1.2 Pulse laser deposition 11 1.2.2 Non-vacuum processes .12 1.2.2.1 Chemical vapor deposition (CVD) 12 ii LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com 1.2.2.2 Chemical bath deposition (CBD) .12 1.2.2.3 Sol-gel 12 1.3 Potential applications 13 1.4 Thesis target 13 CHAPTER EXPERIMENTAL PROCEDURES 15 2.1 Precursor solutions 15 2.1.1 Preparation of precursor solutions 15 2.1.2 Precursor processing .16 2.2 Thin films deposition 18 2.2.1 Tool and equipment 18 2.2.2 Thin films fabrication .18 2.3 Thin films characterization .19 2.3.1 X-ray Diffractometer 19 2.3.2 Four- probe measurement systems 25 2.3.3 UV-Vis Spectroscopy .26 CHAPTER RESULTS AND DISCUSSION 29 3.1 Analysis on structural property .29 3.1.1 Effect of Cu doping concentration 29 3.1.2 Effect of annealing temperature .32 3.2 Analysis on morphological micrographs 35 3.2.1 Effect of Cu doping concentration 35 3.2.2 Effect of annealing temperature .38 3.3 Physical characterization 40 3.3.1 Optical property 40 iii LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com 3.3.1.1 The effect of Cu doped concentration 40 3.3.1.2 Effect of annealing temperature 44 3.3.2 Electrical property 50 3.3.2.1 The effect of Cu doped concentration 50 3.3.2.2 The effect of annealing temperature 51 CONCLUSIONS .53 REFERENCES 54 iv LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com LIST OF FIGURES Page Figure 1.1 Three crystal structures of ZnO [6] Figure 1.2 Wurtzite structure .6 Figure 1.3 Schematic of a Wurtzitic ZnO structure .6 Figure 1.4 Schematic representation of a Zinc blende Figure 1.5 Schematic representation of a NaCl (Rock salt) Figure 1.6 Energy bandgap structure of ZnO [4] Figure 1.7 Sputter deposition .11 Figure 1.8 Pulsed laser deposition .11 Figure 1.9 Sol- gel process 13 Figure 2.1 Zn(CH3COO)2.H2O] 15 Figure 2.2 Cu(CH3COO)2.H2O] 15 Figure 2.3 Ethanol 16 Figure 2.4 Mono Ethanol Amine 16 Figure 2.5 Hotplate .16 Figure 2.6 Analytical balance 16 Figure 2.7 Process of making precursor solution .18 Figure 2.8 Thin films fabrication .19 Figure 2.9 Bragg-Brentano XRD geometry .21 Figure 2.10 Glancing incidence geometry 21 Figure 2.11 Glancing incidence XRD and conventional XRD The sample is a thin film of metal on glass [26] 22 Figure 2.12 X-ray diffractometer (XRD, Bruker, D5005) 22 Figure 2.13 Schemantic representation of the basic SEM components .23 Figure 2.14 Scanning electron microscope (SEM, Nova NANOSEM 450) 25 Figure 2.15 Schematic of four-point probe configuration 26 Figure 2.16 Schematic of a conventional spectrophotometer 28 v LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Figure 3.1 XRD patterns with various Cu doped concentrations: 0%, 0.5%, 1%, 1.5% and 2% 29 Figure 3.2 XRD patterns of 0.5% Cu doping concentration, and temperarure changed: 400, 450, and 500oC 32 Figure 3.3 XRD patterns of 2% Cu doping concentration, and temperarure changed: 400, 450, and 500oC 34 Figure 3.4 SEM graph of CZO thin film with 0% Cu doped concentration 35 Figure 3.5 SEM graph of CZO thin film with 0.5% Cu doped concentration 36 Figure 3.6 SEM graph of CZO thin film with 1% Cu doped concentration 36 Figure 3.7 SEM graph of CZO thin film with 1.5% Cu doped concentration 36 Figure 3.8 SEM graph of CZO thin film with 2% Cu doped concentration 37 Figure 3.9 SEM graph of CZO thin film at 400oC, 0.5% 38 Figure 3.10 SEM graph of CZO thin film at 450oC, 0.5% 38 Figure 3.11 SEM graph of CZO thin film at 500oC, 0.5% 39 Figure 3.12 SEM graph of CZO thin film at 400oC, 2% .39 Figure 3.13 SEM graph of CZO thin film at 450oC, 2% .39 Figure 3.14 SEM graph of CZO thin film at 500oC, 2% .40 Figure 3.15 The absorbance spectra of CZO with various Cu doped concentration: 0%, 0.5%, 1%, 1.5% and 2% .41 Figure 3.16 The bandgap of CZO with various Cu doped concentration 42 Figure 3.17 The transmission spectra with various Cu doped concentration: 0%, 0.5%, 1%, 1.5% and 2% .43 Figure 3.18 The absorbance spectra with various annealing temperatures, 0.5% .45 Figure 3.19 The absorbance spectra with various annealing temperatures, 2% 46 Figure 3.20 The bandgap of CZO with various annealing temperatures, 0.5% 47 Figure 3.21 The bandgap of CZO with various annealing temperature, 2% .48 Figure 3.22 The transmission spectra with various annealing temperature, 0.5% 49 Figure 3.23 The transmission spectra with various annealing temperature, 2% 50 vi LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com LIST OF TABLES Page Table 1.1 Characteristics of ZnO material at room temperature [6] Table 2.1 The mass of starting materials following Cu doped ZnO with different doping concentrations 17 Table 3.1 The lattice parameter of CZO with various Cu doped concentration 31 Table 3.2 The lattice parameters of CZO with various annealing temperatures 34 Table 3.3 The lattice parameters of CZO with various annealing temperatures 35 Table 3.4 The bandgap energy and transmission of CZO thin films with various Cu doped concentration at 500oC 44 Table 3.5 The bandgap energy and transmission of CZO thin films with various annealing temperatures, and Cu doped concentration of 0.5% 48 Table 3.6 The bandgap energy and transmission of CZO thin films with various annealing temperatures, and Cu doped concentration of 2% .48 Table 3.7 The sheet resistance with various Cu doped concentrations 51 Table 3.8 The sheet resistance with various annealing temperatures 52 vii LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com LIST OF ABBREVIATIONS CZO Copper doped zinc oxide CuO Copper oxide ZnO Zinc oxide MEA Monoethanolamine SEM Scanning electronic microscope XRD X-ray diffraction UV-Vis Ultraviolet – Visible viii LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Figure 3.21 The bandgap of CZO with various annealing temperature, 2% Tables 3.5 and 3.6 indicate the Eg and T% of CZO thin films with various annealing temperatures for 0.5 and 2% doping concentrations Table 3.5 The bandgap energy and transmission of CZO thin films with various annealing temperatures, and Cu doped concentration of 0.5% CZO 0.5% 400oC 450oC 500oC Eg (eV) 3.18 3.22 3.16 T (%) 79.67 96.50 86.10 Table 3.6 The bandgap energy and transmission of CZO thin films with various annealing temperatures, and Cu doped concentration of 2% CZO 2% 400oC 450oC 500oC Eg (eV) 3.29 3.22 3.27 T (%) 87.50 87.10 40.30 48 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Figure 3.22 The transmission spectra with various annealing temperature, 0.5% From the transmission spectrum of CZO thin film of 0.5%, it is found that the CZO thin film has the largest transmittance with annealing temperature of 450oC All thin films are strongly absorbed in the ultraviolet region, and have high transmittance in the visible region In this region, the thin films have a transmittance of about 70% or more Here, with the annealing temperature of 450°C, the transmittance is the best CZO thin films at 400°C with low transmittance can be explained by the fact that the thin film quality is not optimum at this temperature, according to the XRD pattern, and the film coating process may contain some of impurities Lamen substrates such as Calcium and Magnesium may affect on the transparency of thin films [37] 49 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Figure 3.23 The transmission spectra with various annealing temperature, 2% 3.3.2 Electrical property 3.3.2.1 The effect of Cu doped concentration Table 3.7 displays the sheet resistance of CZO thin films with various Cu doped concentrations, at the annealing temperature of 500oC It can be extracted from the results below that the sheet resistance of CZO thin films is greatly affected by the Cu doping concentration: the sheet resistance of CZO thin films declines from 169.02 Ω/ sq to 85.46 Ω/ sq when the Cu doping concentration is raised from 0% to 2% Table 3.7 shows that the highest sheet resistance is 169.02 Ω/ sq when the Cu doping concentration is set to 0%, which means lowest value of conductivity The sheet resistance continues to reduce as the Cu concentration is raised to 0.5% and 1% However, at concentration of 1.5%, the sheet resistance rises sharply This shows that the effects of Cu doping concentration on the sheet resistance is still inconsistent [38] 50 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Another conclusion can be extracted from Table 3.7 that the Cu doping concentration of 2% yields the highest level of conductivity, i.e., the sheet resistance of 85.46 Ω/sq is the lowest These results is in agreement with the obtained results from XRD patterns and SEM images as shown before Table 3.7 The sheet resistance with various Cu doped concentrations Concentration Sheet resistance Rs (Ω/ sq) 0% 0.5% 1% 1.5% 2% 169.02 85.46 87.12 93.71 89.25 3.3.2.2 The effect of annealing temperature In addition to the Cu doping concentration, the annealing temperature also has a significant impact on the electrical properties of the CZO thin films Table 3.8 demonstrates the changes in the sheet resistance of CZO thin films at annealing temperatures of 400oC, 450oC and 500oC On the one hand, at 0.5% Cu doped concentration, the sheet resistance of CZO thin films reduces from 93.34 Ω/sq to 73.42 Ω/sq as the annealing temperature rises from 400oC to 500oC At the same time, at 2% Cu doped concentration, as the annealing temperature increases from 400oC to 500oC the sheet resistance of CZO thin films gradually declines from 85.46 Ω/sq to 81.07 Ω/sq Hence, it is empirical that the rising of annealing temperature reduces the sheet resistance, thus enhancing conductivity From the calculated results, it is obvious that the lowest sheet resistance of CZO thin films (73.42 Ω/sq), which means highest conductivity, corresponds to 0.5% Cu doped concentration with annealing temperature of 450oC [9, 39] 51 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Table 3.8 The sheet resistance with various annealing temperatures Concentration 0.5% 2% 93.34 (Ω/sq) 83.28 (Ω/sq) 450oC 73.42 (Ω/sq) 81.07 (Ω/sq) 500oC 89.25 (Ω/sq) 85.46 (Ω/sq) Annealing temperature 400oC 52 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com CONCLUSIONS Cu doped ZnO (CZO) thin films were successfully fabricated by by using a solution-processed method, with various Cu doping concentration of 0%, 0.5%, 1%, 1.5% and 2% The XRD results indicated that CZO thin films were polycrystalline with (100), (002) and (101) preferred orientations, and they were determined in a single phase of Wurtzite structure The optimum crystallization is corresponded to the dopant concentration of 0.5%, and the annealing temperature of 500oC Observation of SEM micrographs showed that the grain size is relatively uniform, but some porous spaces existed One obtained that the grain size decreased with the increase of doped concentration, but increased with the increase of annealing temperature Bandgap energy of CZO thin films is in range of 3.13 - 3.24 eV Sheet resistance of CZO thin films is lower than 100 Ω/sq The achievement results bring the fabricated CZO thin film to be a promising candidate for p-type semiconducting layer in transistor, solar cell or light emitting diode application 53 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com REFERENCES [1] Espitia, P J P., Soares, N D F F., dos Reis Coimbra, J S., de Andrade, N J., Cruz, R S., & Medeiros, E A A (2012) Zinc oxide nanoparticles: synthesis, antimicrobial activity and food packaging applications Food and Bioprocess Technology, 5(5), 1447-1464 Retrievedfrom https://link.springer.com/article/ [2] Gómez-Pozos, H., Arredondo, E., Maldonado Álvarez, A., Biswal, R., Kudriavtsev, Y., Pérez, J., & Olvera Amador, M (2016) Cu-Doped ZnO thin films deposited by a sol-gel process using two copper precursors: Gassensing performance in a propane atmosphere Materials, 9(2), 87 doi:10.3390/ma9020087 [3] Morkoỗ, H., & ệzgỹr, Ü (2008) Zinc oxide: fundamentals, materials and device technology John Wiley & Sons [4] Özgür, Ü., Alivov, Y I., Liu, C., Teke, A., Reshchikov, M., Doğan, S., & Morkoc, H (2005) A comprehensive review of ZnO materials and devices Journal of applied physics, 98(4), 11 [5] U.Ozgur, Y I Alivov and C Liu, "A comprehensive review of ZnO materials and devices," Journal of applied physics, 2005.doi: 10.1063/1.1992666 [6] Touam, T., Boudjouan, F., Chelouche, A., Khodja, S., Dehimi, M., Djouadi, D., & Boudrioua, A (2015) Effect of silver doping on the structural, morphological, optical and electrical properties of sol–gel deposited nanostructured ZnO thin films Optik, 126(24), 5548-5552 doi: 10.1016/j.ijleo.2015.09.066 [7] Eckertova, L (2012) Physics of thin films Springer Science & Business Media 54 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com [8] Boukaous, C., Benhaoua, B., Telia, A., & Ghanem, S (2017) Effect of copper doping sol-gel ZnO thin films: physical properties and sensitivity to ethanol vapor Materials Research Express, 4(10), 105024 doi: 10.1088/2053- 1591/aa8cff [9] Wu, H Y., Cheng, X L., Hu, C H., & Zhou, P (2010) The structure and thermodynamic properties of zinc oxide with wurtzite and rocksalt structure under high pressures Physica B: Condensed Matter, 405(2), 606-612 doi:10.1016/j.physb.2009.09.074 [10] Wu, G M., Chen, Y F., & Lu, H C (2011) Aluminum-doped zinc oxide thin films prepared by sol-gel and RF magnetron sputtering Acta Physica Polonica A, 120(1), 149-152 [11] Bedia, A., Bedia, F Z., Aillerie, M., Maloufi, N., & Benyoucef, B (2015) Morphological and Optical properties of ZnO thin films prepared by spray pyrolysis on glass substrates at various temperatures for integration in solar cell Energy Procedia, 74, 529-538 doi:10.1016/j.egypro.2015.07.740 [12] Lai, L W., & Lee, C T (2008) Investigation of optical and electrical properties of ZnO thin films Materials Chemistry and Physics, 110(2-3), 393396 doi:10.1016/j.matchemphys.2008.02.029 [13] Rudolf, H (Ed.) (2000) Applications of fractional calculus in physics World Scientific [14] Musat, V., Teixeira, B., Fortunato, E., & Monteiro, R C C (2006) Effect of post-heat treatment on the electrical and optical properties of ZnO: Al thin films Thin Solid Films, 502(1-2), 219-222 doi:10.1016/j.tsf.2005.07.278/ [15] Willmott, P R., & Huber, J R (2000) Pulsed laser vaporization and deposition Reviews of Modern Physics, 72(1), 315 55 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com doi:https://doi.org/10.1103/RevModPhys.72.315 [16] Belouet, C (1996) Thin film growth by the pulsed laser assisted deposition technique Applied surface science, 96, 630-642 doi:10.1016/0169- 4332(95)00535-8 [17] Chand, P., Gaur, A., Kumar, A., & Kumar Gaur, U (2014) Structural and optical study of Li doped CuO thin films on Si (100) substrate deposited by pulsed laser deposition Applied Surface Science, 307, 280–286 doi:10.1016/j.apsusc.2014.04.027 [18] Faiz, H., Siraj, K., Rafique, M S., Naseem, S., & Anwar, A W (2015) Effect of zinc induced compressive stresses on different properties of copper oxide thin films Indian Journal of Physics, 89(4), 353-360 [19] Emslie, A G., Bonner, F T., & Peck, L G (1958) Flow of a viscous liquid on a rotating disk Journal of Applied Physics, 29(5), 858-862 doi:10.1063/1.1723300 [20] Danks, A E., Hall, S R., & Schnepp, Z (2016) The evolution of „sol– gel‟chemistry as a technique for materials synthesis Materials Horizons, 3(2), 91-112 doi: 10.1039/C5MH00260E [21] Uche, D O V (2013) Sol-gel technique: A veritable tool for crystal growth Advances in applied science research, 4(1), 506-510 [22] Kojima, I., & Li, B (1999) Structural characterization of thin films by X-ray reflectivity The Rigaku Journal, 16(2), 31 [23] Nesa, M (2016) Characterization of zinc doped copper oxide thin films synthesized by spray pyrolysis technique [24] Kohli, S., Rithner, C D., Dorhout, P K., Dummer, A M., & Menoni, C S (2005) Comparison of nanometer-thick films by x-ray reflectivity and 56 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com spectroscopic ellipsometry Review of scientific instruments, 76(2), 023906 doi:10.1063/1.1848660 [25] Bouroushian, M., & Kosanovic, T (2012) Characterization of thin films by low incidence X-ray diffraction Cryst Struct Theory Appl, 1(3), 35-39 [26] Ryan, T (2001) The Development of Instrumentation for Thin-Film X-ray Diffraction doi:10.1021/ed078p613 [27] Fewster, P F (1996) X-ray analysis of thin films and multilayers Reports on Progress in Physics, 59(11), 1339 [28] Goldstein, J I., Newbury, D E., Michael, J R., Ritchie, N W., Scott, J H J., & Joy, D C (2017) Scanning electron microscopy and X-ray microanalysis Springer [29] Lawes, G (1987) Scanning electron microscopy and X-ray microanalysis [30] Y S "Electrical resistivity measurements: a review," Int J.Mod Phys.: Conf.Series, vol 22, pp 745-756 [31] Shariffudin, S S., Khalid, S S., Sahat, N M., Sarah, M S P., & Hashim, H (2015) Preparation and characterization of nanostructured CuO thin films using sol-gel dip coating In IOP Conference Series: Materials Science and Engineering (Vol 99, No 1, p 012007) IOP Publishing doi:10.1088/1757899X/99/1/012007 [32] Alharbi, F., Bass, J D., Salhi, A., Alyamani, A., Kim, H C., & Miller, R D (2011) Abundant non-toxic materials for thin film solar cells: Alternative to conventional materials Renewable Energy, 36(10), 2753-2758 doi:10.1016/j.renene.2011.03.010 [33] Khan, Z R., Khan, M S., Zulfequar, M., & Khan, M S (2011) Optical and structural properties of ZnO thin films fabricated by sol-gel method Materials 57 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com Sciences and applications, 2(05), 340 doi:10.4236/msa.2011.25044 [34] Zhao, X., Shen, H., Zhou, C., Lin, S., Li, X., Zhao, X., & Lin, H (2016) Preparation of aluminum doped zinc oxide films with low resistivity and outstanding transparency by a sol–gel method for potential applications in perovskite solar cell Thin solid films, 605, 208-214 doi:10.1016/j.tsf.2015.11.001 [35] Chen, G J., Jian, S R., & Juang, J Y (2018) Surface Analysis and Optical Properties of Cu-Doped ZnO Thin Films Deposited by Radio Frequency Magnetron Sputtering Coatings, 8(8), 266 doi:10.3390/coatings8080266 [36] Aravind, A., & Jayaraj, M K (2013) Optical properties of Cu doped ZnO thin films grown by pulsed laser deposition Phys Exp., 3(7), 1-4 [37] Chongsri, K., Aunpang, S., Techitdheera, W., & Pecharapa, W (2013) Preparation and characterization of Cu-doped ZnO sol-gel derived optical thin films In Advanced Materials Research(Vol 802, pp 124-128) Trans Tech Publications doi:https://doi.org/10.4028/www.scientific.net/AMR.802.124 [38] Samarasekara, P., Wijesinghe, U., & Jayaweera, E N (2017) Impedance and electrical properties of Cu doped ZnO thin films arXiv preprint arXiv:1703.02030 [39] Jagadish, C., & Pearton, S J (Eds.) (2011) Zinc oxide bulk, thin films and nanostructures: processing, properties, and applications Elsevier [40] Oxide, Z (2009) Fundamentals, Materials and Device Technology, ed H Morkoỗ and ĩ ệzgỹr [41] Lamri, Z M Cupric Oxide thin films deposition for gas sensor application [42] Morales, J., Sanchez, L., Martin, F., Ramos-Barrado, J R., & Sanchez, M (2005) Use of low-temperature nanostructured CuO thin films deposited by 58 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com spray-pyrolysis in lithium cells Thin Solid Films, 474(1-2), 133-140 doi:10.1016/j.tsf.2004.08.071 [43] Walker, D E., Major, M., Baghaie Yazdi, M., Klyszcz, A., Haeming, M., Bonrad, K., & von Seggern, H (2012) High mobility indium zinc oxide thin film field-effect transistors by semiconductor layer engineering ACS applied materials & interfaces, 4(12), 6835-6841 doi:10.1021/am302004j [44] Wu, H Y., Cheng, X L., Hu, C H., & Zhou, P (2010) The structure and thermodynamic properties of zinc oxide with wurtzite and rocksalt structure under high pressures Physica B: Condensed Matter, 405(2), 606-612 [45] Shen, Y (2014) Development of Thin Film Photovoltaic Cells based on low cost metal Oxides (Doctoral dissertation, University of Bolton) [46] Wu, D., Zhang, Q., & Tao, M (2006) LSDA+ U study of cupric oxide: Electronic structure and native point defects Physical Review B, 73(23), 235206 doi: 10.1021/acsami.5b02545 [47] Akaltun, Y (2015) Effect of thickness on the structural and optical properties of CuO thin films grown by successive ionic layer adsorption and reaction Thin Solid Films, 594, 30-34 doi: https://doi.org/10.1016/j.tsf.2015.10.003 [48] Gopalakrishna, D., Vijayalakshmi, K., & Ravidhas, C (2013) Effect of pyrolytic temperature on the properties of nano-structured Cuo optimized for ethanol sensing applications Journal of Materials Science: Materials in Electronics, 24(3), 1004-1011 [49] Dhanasekaran, V., Mahalingam, T., Chandramohan, R., Rhee, J K., & Chu, J P (2012) Electrochemical deposition and characterization of cupric oxide thin films Thin Solid Films, 520(21), 6608-6613 doi: https://doi.org/10.1016/j.tsf.2012.07.021 59 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com [50] Walker, D E., Major, M., Baghaie Yazdi, M., Klyszcz, A., Haeming, M., Bonrad, K., & von Seggern, H (2012) High mobility indium zinc oxide thin film field-effect transistors by semiconductor layer engineering ACS applied materials & interfaces, 4(12), 6835-6841.doi: https://doi.org/10.1021/am302004j [51] Yasaka, M (2010) X-ray thin-film measurement techniques The Rigaku Journal, 26(2), 1-9 [52] Jeong, J H., Yang, H W., Park, J S., Jeong, J K., Mo, Y G., Kim, H D., & Hwang, C S (2008) Origin of subthreshold swing improvement in amorphous indium gallium zinc oxide transistors Electrochemical and Solid-State Letters, 11(6), H157-H159 [53] X Yu, J Smith, N Zhou, L Zeng, P Guo, Y Xia, A Albarez, S Aghion, H Lin, J Yu, R Chang, M Bedzyk, R Ferragut, T Marks and A Facchetti, "Spary-Combustion synthesis: efficient solution route to high-performance oxide transistors," Proc Natl Acad Sci USA, pp 3217-3222, 2015 doi: 10.1149/1.2903209 [54] Smith, J., Zeng, L., Khanal, R., Stallings, K., Facchetti, A., Medvedeva, J E., & Marks, T J (2015) Cation Size Effects on the Electronic and Structural Properties of Solution‐ Processed In–X–O Thin Films Advanced Electronic Materials, 1(7), 1500146 doi:https://doi.org/10.1002/aelm.201500146 [55] Lee, D H., Chang, Y J., Herman, G S., & Chang, C H (2007) A general route to printable high‐ mobility semiconductors Advanced transparent Materials, 19(6), amorphous 843-847 oxide doi: https://doi.org/10.1002/adma.200600961 [56] Niederberger, M., Garnweitner, G., Buha, J., Polleux, J., Ba, J., & Pinna, N 60 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com (2006) Nonaqueous synthesis of metal oxide nanoparticles: Review and indium oxide as case study for the dependence of particle morphology on precursors and solvents Journal of Sol-Gel Science and Technology, 40(2-3), 259-266 [57] Norris, B J., Anderson, J., Wager, J F., & Keszler, D A (2003) Spin-coated zinc oxide transparent transistors Journal of Physics D: Applied Physics, 36(20), L105 [58] Park, J H., Yoo, Y B., Lee, K H., Jang, W S., Oh, J Y., Chae, S S., & Baik, H K (2013) Boron-doped peroxo-zirconium oxide dielectric for highperformance, low-temperature, solution-processed indium oxide thin-film transistor ACS applied materials & interfaces, 5(16), 8067-8075 doi: https://doi.org/10.1021/am402153g [59] H Hoang (2018) Solution-proccessed In-Si-O thin-film transistor fabricated via spin coating method, Master thesis [60] D V Nguyen (2018) Chacterrization on solution-proccessed P-type Cuo thin films for electronic devices application, Master thesis 61 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com LIST OF PRESENTATIONS/PUBLICATIONS [1] Nguyen Van Dung, Le Thi Hien, Nguyen Quang Hoa, Bui Nguyen Quoc Trinh (2018), “YEP Channel CuO thin film transistors fabricateed by solution processing”, International Workshop on Advanced Materials and Nanotechnology 2018 (IWAMN 2016), Ninh Binh City, Vietnam, November 7-11, 2018 [2] Le Thi Hien, Nguyen Quang Hoa, Bui Nguyen Quoc Trinh (2019), “Characterization on Cu doped ZnO thin films prepared by solution processing”, The 2019 Hanoi International Symposium on Advanced Materials and Devices (HISAMD 2019), Hanoi, Vietnam, 10-12th January, 2019 62 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com ...VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY LE THI HIEN UNDOPED AND DOPED ZNO – BASED THIN FILMS BY A SOLUTION PROCESS: PREPARATION AND CHARACTERIZATION MAJOR: NANOTECHNOLOGY... The transmission spectra with various annealing temperature, 2% 50 vi LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com LIST OF TABLES Page Table 1.1 Characteristics of ZnO material at room... researched and 13 LUAN VAN CHAT LUONG download : add luanvanchat@agmail.com fabricated two materials with both benefits, that is, they have good conductivity and transparent as well Some are known as