Green and low cost preparation of cigse thin film by a nanocrystals ink based spin coating method

Ph.D Thesis Green and low-cost preparation of CIGSe thin film by a nanocrystals ink based spin-coating method Graduate School of Yeungnam University School of Chemical Engineering Major in Chemical Engineering Le Thi Thuy Trang Advisor: Prof Chinho Park Co-advisor: Prof JaeHong Kim February 2020 i ii Ph.D Thesis Green and low-cost preparation of CIGSe thin film by a nanocrystals ink based spin-coating method Advisor: Prof Chinho Park Co-advisor: Prof JaeHong Kim Presented as Ph.D Thesis February 2020 Graduate School of Yeungnam University School of Chemical Engineering Major in Chemical Engineering Le Thi Thuy Trang iii Acknowledgements I woud like to express my deep gratitude to my advisor, Professor Chinho Park at the School of chemical engineering He has provided me the invaluable contributions in the research work by various profitable discussions His devoted instructions have been my sources of inspiration during Ph.D periods, and have given me the great encouragement to fulfill both the research and writing of this thesis I deeply thank to Professor JaeHong Kim, who has supported me to complete this Ph.D program My special thanks also go to Dr Babu, Dr Vasu and Dr Nguyen for their valuable comments and suggestions in my research I am thankful to the IMSL lab’s members who have ever helped me many things I will remember for their trust and friendship Your sentiments toward me are quite precious I thank to my family for giving me a wider perspective on things, unlimited forbearance, and the time deprived from them Last, I gratefully acknowledge Yeungnam university and BK 21 program because of their supports December, 2019 Le Thi Thuy Trang iv Abstract This thesis presents our efforts that aim towards a green and low cost prodedure to fabricate CIGSe thin films which would be used as absorber layers for the thin film solar cell industry So, an ―ink‖ solution based process, using spin-coating technique, followed by annealing in selenium environment with different temperature programs was utilized to prepare CIGSe thin film Firstly, CIGSe nanoparticles were synthesized using NaBH4 containing green solvent – ethanol by a sonochemical method The effect of the ultrasonification time intervals on the synthesis was investigated in the range of 2-5 hr, hr was found to be the most suitable time to obtain the expected CuIn0.7Ga0.3Se2 compounds The as-synthesized CIGSe nanoparticles possessed a tetragonal structure with quasi-spherical shape, and the targeted Cu(In0.7Ga0.3)Se2 composition A new reaction scheme is proposed to explain the role of NaBH4 in the plausible reaction paths The non-toxic solvent used in the synthesis with no additional heating makes the developed method cheaper and ―greener‖ than the previously reported methods Next, three different solvents: 2-propanol, 2-methoxyethanol, and their 2:1 mixture (v/v ratio) were investigated as a dispersion medium for the as-synthesized CIGSe nanocrystals to form a stable ink solution The last one – mixture of 2-propanol : 2-methoxyethanol = : (v/v) – was found to be the most suitable Furthermore, the influences of various annealing modes on the CIGSe grain size and density in the resulting film were also studied The as-prepared CIGSe thin film was around µm thick, possessed a tetragonal structure, and the band gap energy was estimated about ~ 1.3-1.4 eV The newly developed cheaper and ―greener‖ non-vacuum process was applied successfully from the nanocrystals synthesis to the formation of ―ink‖ solution, and produced v high quality thin films, which opens a new route to the cost-competitive commercialization of CIGSe thin film solar cells vi Contents Acknowledgements i Abstract v List of figures viii Chapter 1: Literature Overview 1.1 The material system of Cu(In,Ga)Se2 quaternary 1.1.1 Introduction of the structural property 1.1.2 Optical and electrical properties 1.2 Overview of solar cell 1.2.1 The story of solar cell 1.2.2 The operating principle of solar cell 10 1.3 Thin film deposition techniques 10 1.3.1 The vacuum method 11 1.3.1.1 Co-evaporation 11 1.3.1.2 Sputtering (two-step process) 13 1.3.1.3 Chemical vapor deposition (CVD) 14 1.3.2 The non-vacuum method 15 1.3.2.1 The nanoparticles based method 16 1.3.2.2 Direct solution based process 18 1.4 Physical methods for characterizing solids 18 1.4.1 X-ray diffraction 18 Chapter 2: Green and low-cost synthesis of CIGSe nanoparticles using ethanol as a solvent by a sonochemical method - a new approach 31 2.1 Introduction 31 2.2 Experiment details: 32 2.3 Results and discussion 34 Chapter 3: The formation of CIGSe thin film by a nanocrystals ink based spin-coating method 44 3.1 Introduction 44 3.2 Experiment detail 45 3.3 Results and discussion 48 Conclusions 56 References 57 List of puplications 70 vii List of figures Chapter Fig 1.1: The unit cell of the chalcopyrite lattice structure a) CuInSe2, b) Cu(In,Ga)Se2 Fig 1.2: The working of a silicon solar cell Fig 1.3: The structure of a dye sensitized solar cells Fig 1.4: Mechanism of dye sensitized solar cell Fig 1.5: Basic structure or Organic Solar Cell Fig 6: The operating principle of solar cell 10 Fig 7: Schematic of evaporation system 11 Fig 8: Schematic illustration of different coevaporation recipes 13 Fig 1.9: Schematic of sputtering system 14 Fig 1.10: Schematic of chemical vapor deposition system 15 Fig 1.11: Schematic illustration of X-ray generation system 20 Fig 12: (a) Section through an X-ray tube (b) An X-ray emission spectrum 20 Fig 1.13: Basic components of a monochromatic XPS system 23 Fig 1.14: Schematic illustration of a raman spectroscopy system 24 Fig 1.15: Schematic illustration of scanning electron microscopy system 26 Fig 1.16: Schematic illustration of Scanning electron microscopy system 28 Fig 1.17: Block diagram of DTA 29 Fig 1.18: Schematic illustration of differential scanning calorimetry system 30 viii Chapter Fig 2.1: XRD patterns of the CIGSe nanoparticles synthesized with difference ultrasonification time 36 Fig 2.2: SEM images of CIGSe NPs with ultrasonification time of hr (a), 3.5 hr (b), 4.5 hr (c) and hr (d) 37 Fig 2.3: Raman spectra of as-prepared CuIn0.7Ga0.3Se2 NPs with ultrasonification time of hr 38 Fig 2.4: a) XPS survey spectrum and Cu 2p (b), In 3d (c), Ga 2p (d) , and Se 3d (e ) core-level spectrum of as-synthesized CuIn0.7Ga0.3Se2 nanoparticles 40 Fig 2.5: TEM images of CIGSe nanoparticles with ultrasonification time of hr before (a) and after (b) annealed at 500 oC 41 Fig 2.6: XRD pattern of CuIn0.7Ga0.3Se2 NPs before and after annealed at 500 oC 42 Fig 2.7: Absorption spectrum (a) and plot of (αhν)2 versus photon energy hν (b) of the annealed CuIn0.7Ga0.3Se2 nanoparticles 43 Chapter Fig 3.1: The images of colloidal solutions with different dispersion mediums: 2-propanol (a), 2methoxyethanol (b) and solvent mixture of 2-propanol and 2-methoxyethanol (c) after being kept in month 48 Fig 2: The images of the spin coated films by 2-propanol solvent based ink solution (a), and solvent mixture based ink solution (b) 49 Fig 3: Cross-section SEM image of CIGSe thin film with the first annealing mode 49 Fig 4: Cross-section SEM image of CIGSe thin film with the second annealing mode 51 Fig 5: Cross-section SEM image of CIGSe thin film with the third annealing mode 52 Fig 6: Surface SEM image of CIGSe thin film with the third annealing mode 53 ix Fig 7: XRD pattern of CIGSe thin film after being annealed with the third annealing mode 54 Fig 3.8: Plot of (αhν)2 versus photon energy hν of CIGSe thin film after being annealed with the third annealing mode 55 x [13] J Czochralski, Ein neues Verfahren zur Messung der Kristallisationsgeschwindigkeit von Metallen, Zeitschrift für Phys Chemie, 92 (1918) 219–221 [14] M.A Green, Y Hishikawa, E.D Dunlop, D.H Levi, J Hohl-Ebinger, M Yoshita, A.W.Y Ho-Baillie, Solar cell efficiency tables (Version 53), Progress in Photovoltaics: Research and Applications, 27 (2019) 3-12 [15] R.L Easton, and M J Votaw, Vanguard I IGY satellite (1958 Beta), Rev Sci Instrum., 30, 70-75, Feb 1959 [16] K Ranabhat, L Patrikeev, A Revina, K Andrianov, V Lapshinsky, E Sofronova, An introduction to solar cell technology, 14 (2016) 481-491 [17] M.G Brian O'Regan, A low-cost, high-efficiency solar cell based on dye-sensitized colloidal Ti02 films Nature, 353 (1991) 737-740 [18] A Ali, N Bakr, S Jassim, Fabrication of Dye Sensitized Solar Cell and Efficiency Enhancement by Using N719 and Z907 Dyes Mixture, Journal of Photonic Materials and Technology, (2016) [19] https://www.wikiwand.com/en/Dye-sensitized_solar_cell [20] https://en.wikipedia.org/wiki/Organic_solar_cell [21] D Vatansever, E Siores, T Shah, Alternative Resources for Renewable Energy: Piezoelectric and Photovoltaic Smart Structures, (2012) [22] R.A.M.a.W.S Chen, High photocurrent polycrystalline thin-film CdS/CuInSe2 solar cell, Appl Phys Lett., 36 (1980) 371–373 [23] R.A.M.a.W.S Chen, Development of a 9.4% efficient thin-film CuInSe2/CdS solar cell, Conference Record of the Fifteenth IEEE Photovoltaic Specialists Conference, (1981) 800–804 58 [24] W.S.C J M Stewart, W E Devaney, and R A Mickelsen, Thin film polycrystalline CuIn1−xGaxSe2 solar cells, Proc of the 7th Int Conf on Ternary and Multinary Compounds, (1987) 59–64 [25] J.S J Kessler, and L Stolt, Analysis of CIGS films and devices resulting from different Curich to Cu-poor transitions, Proceedings of the 17th European Photovoltaic Solar Energy Conference, (2001) 1019–1022 [26] A Romeo, M Terheggen, D Abou-Ras, D.L Bätzner, F.J Haug, M Kälin, D Rudmann, A.N Tiwari, Development of thin-film Cu(In,Ga)Se2 and CdTe solar cells, Progress in Photovoltaics: Research and Applications, 12 (2004) 93-111 [27] S.S.C T L Chu, S C Lin and J Yue, Large Grain Copper Indium Diselenide Films, J Electrochem Soc., 131 (1984) 2182–2185 [28] H Adachi, T Hata, K Wasa, - Basic Process of Sputtering Deposition, in: K Wasa, I Kanno, H Kotera (Eds.) Handbook of Sputtering Technology (Second Edition), William Andrew Publishing, Oxford, 2012, pp 295-359 [29] J Tang, S Hinds, S.O Kelley, E.H Sargent, Synthesis of Colloidal CuGaSe2, CuInSe2, and Cu(InGa)Se2 Nanoparticles, Chemistry of Materials, 20 (2008) 6906-6910 [30] M Ahmadi, S.S Pramana, L Xi, C Boothroyd, Y.M Lam, S Mhaisalkar, Evolution Pathway of CIGSe Nanocrystals for Solar Cell Applications, The Journal of Physical Chemistry C, 116 (2012) 8202-8209 [31] Y.C.L H.Z Zhong, M.F Ye, Z.Z Zhu, Y Zhou, C.H Yang, Nanotechnology, 18 (2007) 025602–025607 59 [32] M.-Y Chiang, S.-H Chang, C.-Y Chen, F.-W Yuan, H.-Y Tuan, Quaternary CuIn(S1−xSex)2 Nanocrystals: Facile Heating-Up Synthesis, Band Gap Tuning, and Gram-Scale Production, The Journal of Physical Chemistry C, 115 (2011) 1592-1599 [33] M Singh, J Jiu, T Sugahara, K Suganuma, Photonic sintering of thin film prepared by dodecylamine capped CuInxGa1−xSe2 nanoparticles for printed photovoltaics, Thin Solid Films, 565 (2014) 11-18 [34] Y.G Chun, K.H Kim, K.H Yoon, Synthesis of CuInGaSe2 nanoparticles by solvothermal route, Thin Solid Films, 480-481 (2005) 46-49 [35] Y.X B Li, J Huang, Y Qian, Synthesis by a solvothermal route and characterization of CuInSe2 nanowhiskers and nanoparticles, in: Adv Mater., 1999, pp 1456–1459 [36] S.-I Gu, H.-S Shin, D.-H Yeo, Y.-W Hong, S Nahm, Synthesis of the single phase CIGS particle by solvothermal method for solar cell application, Current Applied Physics, 11 (2011) S99-S102 [37] C.-H Wu, F.-S Chen, S.-H Lin, C.-H Lu, Preparation and characterization of CuInSe2 particles via the hydrothermal route for thin-film solar cells, Journal of Alloys and Compounds, 509 (2011) 5783-5788 [38] J.B Shim, C.G Kim, D.J Jeon, T.-M Chung, K.-S An, S.S Lee, J.S Lim, S.J Jeong, B.K Park, Y.K Lee, Hydrothermal synthesis of CuInSe2 nanoparticles in acetic acid, Journal of Physics and Chemistry of Solids, 74 (2013) 867-871 [39] J Ramkumar, S Ananthakumar, S Moorthy Babu, Hydrothermal synthesis and characterization of CuInSe2 nanoparticles using ethylenediamine as capping agent, Solar Energy, 106 (2014) 177-183 60 [40] F Fievet, J.P Lagier, B Blin, B Beaudoin, M Figlarz, Homogeneous and heterogeneous nucleations in the polyol process for the preparation of micron and submicron size metal particles, Solid State Ionics, 32-33 (1989) 198-205 [41] H Grisaru, O Palchik, A Gedanken, V Palchik, M.A Slifkin, A.M Weiss, MicrowaveAssisted Polyol Synthesis of CuInTe2 and CuInSe2 Nanoparticles, Inorganic Chemistry, 42 (2003) 7148-7155 [42] J Der Wu, L Ting Wang, C Gau, Synthesis of CuInGaSe2 nanoparticles by modified polyol route, Solar Energy Materials and Solar Cells, 98 (2012) 404-408 [43] J.-H Cha, S.J Noh, D.-Y Jung, Synthesis and Nanostructures of Metal Selenide Precursors for Cu(In,Ga)Se2 Thin-Film Solar Cells, ChemSusChem, (2015) 2407-2413 [44] A.C Badgujar, R.O Dusane, S.R Dhage, Sonochemical synthesis of CuIn0.7Ga0.3Se2 nanoparticles for thin film photo absorber application, Materials Science in Semiconductor Processing, 81 (2018) 17-21 [45] https://vi.wikipedia.org/wiki/Wilhelm_R%C3%B6ntgen [46] L Smart, Moore, E (2012) Solid State Chemistry Boca Raton: CRC Press, https://doi.org/10.1201/b12047 [47] https://en.wikipedia.org/wiki/X-ray_photoelectron_spectroscopy [48] https://www3.nd.edu/~kamatlab/facilities_spectroscopy.html [49] https://science.howstuffworks.com/scanning-electron-microscope2.htm [50] http://www.biosciencenotes.com/transmission-electron-microscope-tem/ [51] R Sah, S.K Dutta, Kinetic Studies of Iron Ore–Coal Composite Pellet Reduction by TG– DTA, Transactions of the Indian Institute of Metals, 64 (2011) 583-591 61 [52] S Bibi, D.H Bremner, M Macdougall-Heasman, R Reid, K Simpson, A Tough, S Waddell, I.J Stewart, K.H Matthews, A preliminary investigation to group disparate batches of licit and illicit diazepam tablets using differential scanning calorimetry, Analytical Methods, (2015) 8597-8604 [53] K.R M.A Contreras, J AbuShama, F Hasoon, D L Young, B Egaas, R Noufi, Diode characteristics in state-of-the-art ZnO/CdS/ Cu(In1-xGax)Se2 solar cells, Prog Photovolt: Res Appl , 13 (2005) 209–216 [54] M.J.R M.A Contreras, R Noufi, Characterization of Cu(In,Ga)Se2 materials used in record performance solar cells, Thin Solid Films 511-512 (2006) 51–54 [55] M.A.C I Repins, B Egaas, C DeHart, J Scharf, C.L Perkins, B To, R Noufi, 19.9%efficient ZnO/CdS/ CuInGaSe2 Solar Cell with 81.2% Fill Factor, Prog Photovolt: Res Appl., 16 (2008) 235–239 [56] P.-m.J ZSW sets new thin film solar world record with 22.6% efficient CIGS PV cell [57] A Chirila, S Buecheler, F Pianezzi, P Bloesch, C Gretener, A.R Uhl, C Fella, L Kranz, J Perrenoud, S Seyrling, R Verma, S Nishiwaki, Y.E Romanyuk, G Bilger, A.N Tiwari, Highly efficient Cu(In,Ga)Se2 solar cells grown on flexible polymer films, Nature materials, 10 (2011) 857-861 [58] R Wuerz, A Eicke, M Frankenfeld, F Kessler, M Powalla, P Rogin, O Yazdani-Assl, CIGS thin-film solar cells on steel substrates, Thin Solid Films, 517 (2009) 2415-2418 [59] R Wuerz, A Eicke, F Kessler, S Paetel, S Efimenko, C Schlegel, CIGS thin-film solar cells and modules on enamelled steel substrates, Solar Energy Materials and Solar Cells, 100 (2012) 132-137 62 [60] A.C F Pianezzi, P Bloesch, S Seyrling, S Buecheler, L Kranz, C Fella, A.N Tiwari, Electronic properties of Cu(In,Ga)Se2 solar cells on stainless steel foils without diffusion barrier, Prog Photovolt: Res Appl , 20 (2012) 253–259 [61] M Powalla, P Jackson, W Witte, D Hariskos, S Paetel, C Tschamber, W Wischmann, High-efficiency Cu(In,Ga)Se2 cells and modules, Solar Energy Materials and Solar Cells, 119 (2013) 51-58 [62] G Shen, D Chen, K Tang, Z Fang, J Sheng, Y Qian, Polyol-mediated synthesis of porous nanocrystalline CuInS2 foam, Journal of Crystal Growth, 254 (2003) 75-79 [63] C.-J Wang, S.-C Shei, S.-J Chang, Novel solution process for synthesis of CIGS nanoparticles using polyetheramine as solvent, Materials Letters, 122 (2014) 52-54 [64] M.G Panthani, V Akhavan, B Goodfellow, J.P Schmidtke, L Dunn, A Dodabalapur, P.F Barbara, B.A Korgel, Synthesis of CuInS2, CuInSe2, and Cu(InxGa1-x)Se2 (CIGS) Nanocrystal ―Inks‖ for Printable Photovoltaics, Journal of the American Chemical Society, 130 (2008) 16770-16777 [65] C Yu, Q Fan, Y Xie, J Chen, Q shu, J.C Yu, Sonochemical fabrication of novel squareshaped F doped TiO2 nanocrystals with enhanced performance in photocatalytic degradation of phenol, Journal of Hazardous Materials, 237-238 (2012) 38-45 [66] T.J Mason, The uses of ultrasound in chemistry, Royal Society of Chemistry, Cambridge, 1990 [67] R Kerner, O Palchik, A Gedanken, Sonochemical and Microwave-Assisted Preparations of PbTe and PbSe A Comparative Study, Chemistry of Materials, 13 (2001) 1413-1419 [68] H Tanino, H Deai, H Nakanishi, Raman Spectra of CuGaxIn1-xSe2, Japanese Journal of Applied Physics, 32 (1993) 436 63 [69] R.K Wolfram Witte, Axel Eicke and Michael Powalla, INFLUENCE OF THE GA CONTENT ON THE MO/CU(IN,GA)SE2 INTERFACE FORMATION, Proceedings of the fourth IEEE World Conference on Photovoltaic Energy Conversion (WCPEC-4) Waikoloa, USA, (2006) 553-556 [70] L Vegard, Die Konstitution der Mischkristalle und die Raumfüllung der Atome, Zeitschrift für Physik, 5(1) (1921) 17-26 [71] A.R Denton, N.W Ashcroft, Vegard's law, Physical Review A, 43 (1991) 3161-3164 [72] M.C Biesinger, L.W.M Lau, A.R Gerson, R.S.C Smart, Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn, Applied Surface Science, 257 (2010) 887-898 [73] A.V.N C.D Wagner, A Kraut-Vass, J.W Allison, C.J Powell, J.R.Jr Rumble, NIST Standard Reference Database 20, Version 3.4 (web version) (http:/srdata.nist.gov/xps) 2003 [74] D Briggs, Handbook of X-ray Photoelectron Spectroscopy C D Wanger, W M Riggs, L E Davis, J F Moulder and G E.Muilenberg Perkin-Elmer Corp., Physical Electronics Division, Eden Prairie, Minnesota, USA, 1979 190 pp $195, Surface and Interface Analysis, (1981) v-v [75] D Cahen, P.J Ireland, L.L Kazmerski, F.A Thiel, X‐ray photoelectron and Auger electron spectroscopic analysis of surface treatments and electrochemical decomposition of CuInSe2 photoelectrodes, Journal of Applied Physics, 57 (1985) 4761-4771 [76] M Gr tzel, Heterogeneous photochemical electron transfer, CRC Press, Boca Raton, Fla., 1989 [77] G.S Chen, J.C Yang, Y.C Chan, L.C Yang, W Huang, Another route to fabricate singlephase chalcogenides by post-selenization of Cu–In–Ga precursors sputter deposited from a single ternary target, Solar Energy Materials and Solar Cells, 93 (2009) 1351-1355 64 [78] A Ihlal, K Bouabid, D Soubane, M Nya, O Ait-Taleb-Ali, Y Amira, A Outzourhit, G Nouet, Comparative study of sputtered and electrodeposited CI(S,Se) and CIGSe thin films, Thin Solid Films, 515 (2007) 5852-5856 [79] V Garg, B.S Sengar, P Sharma, A Kumar, Aaryashree, S Kumar, S Mukherjee, Sputterinstigated plasmon-enhanced optical backscattering layer in ultrathin solar cells: Application of GZO in CIGSe material system, Solar Energy, 174 (2018) 35-44 [80] B Ayachi, T Aviles, J.-P Vilcot, C Sion, P Miska, Room temperature pulsed-DC sputtering deposition process for CIGS absorber layer: Material and device characterizations, Thin Solid Films, 660 (2018) 175-179 [81] Z Yu, C Yan, Y Yan, Y Zhang, T Huang, W Huang, S Li, L Liu, Y Zhang, Y Zhao, Effect of annealing temperature on properties of RF sputtered Cu(In,Ga)Se2 thin films, Applied Surface Science, 258 (2012) 8527-8532 [82] M.A Contreras, K Ramanathan, J AbuShama, F Hasoon, D.L Young, B Egaas, R Noufi, SHORT COMMUNICATION: ACCELERATED PUBLICATION: Diode characteristics in state-of-the-art ZnO/CdS/Cu(In1−xGax)Se2 solar cells, Progress in Photovoltaics: Research and Applications, 13 (2005) 209-216 [83] M.A.C I Repins, B Egaas, C DeHart, J Scharf, C.L Perkins, B To, R Noufi, 19,9%efficient ZnO/CdS/ CuInGaSe2 Solar Cell with 81,2% Fill Factor, Prog Photovolt: Res Appl , 16 (2008) 235–239 [84] A Drici, M Mekhnache, A Bouraoui, A Kachouane, J.C Bernède, A Amara, M Guerioune, Cu(In1−xGax)Se2 co-evaporated thin films from simple tungsten baskets—Influence of the gallium source, Materials Chemistry and Physics, 110 (2008) 76-82 65 [85] T Drobiazg, L Arzel, A Dönmez, P Zabierowski, N Barreau, Influence of indium/gallium gradients on the Cu(In,Ga)Se2 devices deposited by the co-evaporation without recrystallisation, Thin Solid Films, 582 (2015) 47-50 [86] R Caballero, V Izquierdo-Roca, X Fontané, C.A Kaufmann, J Álvarez-García, A Eicke, L Calvo-Barrio, A Pérez-Rodríguez, H.W Schock, J.R Morante, Cu deficiency in multi-stage co-evaporated Cu(In,Ga)Se2 for solar cells applications: Microstructure and Ga in-depth alloying, Acta Materialia, 58 (2010) 3468-3476 [87] J López-García, H Xie, V Izquierdo-Roca, D Sylla, X Fontané, M Blanes-Guardia, F Ramos, M Espindola-Rodriguez, S López-Marino, E Saucedo, A Pérez-Rodriguez, Synthesis of CuIn(S,Se)2 quaternary alloys by screen printing and selenization-sulfurization sequential steps: Development of composition graded absorbers for low cost photovoltaic devices, Materials Chemistry and Physics, 160 (2015) 237-243 [88] J Kubo, Y Matsuo, T Wada, A Yamada, M Konagai, Fabrication of Cu(In,Ga)Se2 Films by a Combination of Mechanochemical Synthesis, Wet Bead Milling, and a Screen Printing/sintering Process, MRS Proceedings, 1165 (2011) 1165-M1105-1113 [89] M Pscherer, M Günthner, C.A Kaufmann, A Rahm, G Motz, Thin-film silazane/alumina high emissivity double layer coatings for flexible Cu(In,Ga)Se2 solar cells, Solar Energy Materials and Solar Cells, 132 (2015) 296-302 [90] D Zhao, Q Tian, Z Zhou, G Wang, Y Meng, D Kou, W Zhou, D Pan, S Wu, Solutiondeposited pure selenide CIGSe solar cells from elemental Cu, In, Ga, and Se, Journal of Materials Chemistry A, (2015) 19263-19267 [91] J.-J Park, J.-G Lee, D.-Y Kim, J.-H Lee, J.H Yun, J Gwak, Y.-J Eo, A Cho, M.T Swihart, S.S Al-Deyab, S Ahn, D Kim, S.S Yoon, Rapid supersonic spraying of 66 Cu(In,Ga)(S,Se)2 nanoparticles to fabricate a solar cell with 5.49% conversion efficiency, Acta Materialia, 123 (2017) 44-54 [92] J.-J Park, J.-G Lee, S.C James, S.S Al-Deyab, S Ahn, S.S Yoon, Thin-film metallization of CuInGaSe2 nanoparticles by supersonic kinetic spraying, Computational Materials Science, 101 (2015) 66-76 [93] H.S Choi, E Choi, A Kim, S.P Yoon, S.G Pyo, Microstructrual evolution of all-wetprocessed CIGS films using Raman spectroscopy, physica status solidi (a), 211 (2014) 18771881 [94] G.S Park, S.J Park, J.S Jeong, V.B Chu, Y.J Hwang, B.K Min, Synthesis of the solutionprocessed wide band-gap chalcopyrite CuGa(S,Se)2 thin film and its application to photovoltaics, Thin Solid Films, 621 (2017) 70-75 [95] J Bi, L Yao, J Ao, S Gao, G Sun, Q He, Z Zhou, Y Sun, Y Zhang, Pulse electrodeposition of copper on molybdenum for Cu(In,Ga)Se2 and Cu2ZnSnSe4 solar cell applications, Journal of Power Sources, 326 (2016) 211-219 [96] S Rampino, M Bronzoni, L Colace, P Frigeri, E Gombia, C Maragliano, F Mezzadri, L Nasi, L Seravalli, F Pattini, G Trevisi, M Motapothula, T Venkatesan, E Gilioli, Lowtemperature growth of single-crystal Cu(In,Ga)Se2 films by pulsed electron deposition technique, Solar Energy Materials and Solar Cells, 133 (2015) 82-86 [97] M Kaelin, D Rudmann, F Kurdesau, H Zogg, T Meyer, A.N Tiwari, Low-cost CIGS solar cells by paste coating and selenization, Thin Solid Films, 480-481 (2005) 486-490 [98] D Lee, Y Choi, K Yong, Morphology and crystal phase evolution of doctor-blade coated CuInSe2 thin films, Journal of Crystal Growth, 312 (2010) 3665-3669 67 [99] F Huang, A.-H Yan, H Zhao, Z Li, X.-P Cai, Y.-H Wang, Y.-C Wu, S.-B Yin, Y.-H Qiang, CIS and CIGS nanomaterials prepared by solvothermal method and their spectral properties, Crystal Research and Technology, 49 (2014) 953-958 [100] Y.-C Wang, Y.-T Yen, C.-H Liu, C.-H Chen, W.-C Kuo, J.-Y Juang, C.-H Lai, Y.-L Chueh, Fabrication of large-scale single-crystal Cu(In,Ga)Se2 nanotip arrays solar cell by onestep ion milling processes, Thin Solid Films, 546 (2013) 347-352 [101] M Latha, R Aruna Devi, S Velumani, Hot injection synthesis of Cu(In, Ga)Se2 nanocrystals with tunable bandgap, Optical Materials, 79 (2018) 450-456 [102] J Lee, J Chang, J.-H Cha, Y Lee, J Han, D.-Y Jung, E Choi, B Hong, Large‐Scale, Surfactant‐Free Solution Syntheses of Cu(In,Ga)(S,Se)2 Nanocrystals for Thin Film Solar Cells, European Journal of Inorganic Chemistry, 2011 (2011) 647-651 [103] P Jackson, D Hariskos, E Lotter, S Paetel, R Wuerz, R Menner, W Wischmann, M Powalla, New world record efficiency for Cu(In,Ga)Se2 thin-film solar cells beyond 20%, Progress in Photovoltaics: Research and Applications, 19 (2011) 894-897 [104] D Abou-Ras, G Kostorz, D Bremaud, M Kälin, F.V Kurdesau, A.N Tiwari, M Döbeli, Formation and characterisation of MoSe2 for Cu(In,Ga)Se2 based solar cells, Thin Solid Films, 480-481 (2005) 433-438 [105] D Abou-Ras, D Mukherji, G Kostorz, D Brémaud, M Kälin, D Rudmann, M Döbeli, A.N Tiwari, Dependence of the MoSe2 Formation on the Mo Orientation and the Na Concentration for Cu(In,Ga)Se2 Thin-Film Solar Cells, MRS Proceedings, 865 (2011) F8.1 [106] R Krishnan, E.A Payzant, R Kacnyzki, U Schoop, J Britt, R Noufi, T.J Anderson, Reaction kinetics and pathways of MoSe2, in: 2010 35th IEEE Photovoltaic Specialists Conference, 2010, pp 001006-001008 68 [107] T Eisenbarth, T Unold, R Caballero, C.A Kaufmann, H.-W Schock, Interpretation of admittance, capacitance-voltage, and current-voltage signatures in Cu(In,Ga)Se2 thin film solar cells, Journal of Applied Physics, 107 (2010) 034509 [108] T Wada, N Kohara, S Nishiwaki, T Negami, Characterization of the Cu(In,Ga)Se2/Mo interface in CIGS solar cells, Thin Solid Films, 387 (2001) 118-122 [109] R Caballero, C.A Kaufmann, T Eisenbarth, A Grimm, I Lauermann, T Unold, R Klenk, H.W Schock, Influence of Na on Cu(In,Ga)Se2 solar cells grown on polyimide substrates at low temperature: Impact on the Cu(In,Ga)Se2/Mo interface, Applied Physics Letters, 96 (2010) 092104 [110] R Caballero, M Nichterwitz, A Steigert, A Eicke, I Lauermann, H.W Schock, C.A Kaufmann, Impact of Na on MoSe2 formation at the CIGSe/Mo interface in thin-film solar cells on polyimide foil at low process temperatures, Acta Materialia, 63 (2014) 54-62 [111] M Gratzel, Heterogeous Photochemical Electron Transfer, CRC Press, Boca Raton, FL, 1988 69 List of puplications Trang T.T Le, Tuan V Vu, Hyoeun Kim, Dong-seob Jeong, Babu Pejjai, Nguyen Tam Nguyen Truong and Chinho Park Green and low-cost synthesis of CIGSe nanoparticles using ethanol as a solvent by a sonochemical method - a new approach Materials Chemistry and Physics (IF =2.781 ) Trang T.T Le, Nam Le, Mohan Reddy Pallavolu, Dong-seob Jeong, Babu Pejjai, Nguyen Tam Nguyen Truong and Chinho Park Green and low-cost preparation of CIGSe thin film by a nanocrystals ink based spincoating method Korean Journal of Chemical Engineering (IF=2.199) Babu Pejjai, Vasudeva Reddy Minnam Reddy, Kondaiah Seku, Haeyun Cho, Mohan Reddy Pallavolu, Trang T.T Le, Dong-seob Jeong, Tulasi Ramakrishna Reddy Kotte, and Chinho Park Fabrication of CuInSe2 thin film solar cells using cherry blossom tree gum assisted binary Cu-Se and In-Se nanoparticles Korean Journal of Chemical Engineering (IF=2.199) 70 나노 결정 기반 스핀코팅법에 의한 CIGSe 박막의 녹색 및 저비용 합성 연구 레티투이트랑 엥남대 학교 대 학원 화학공학과 화학공학전공 지도교수: 박진호, 김재홍 교수 요약 이 녺문은 박막 태양젂지 산업의 흡수기 층으로 사용될 CIGSe 박막을 제작하기 위핚 녹색과 저비용 계획을 목표로 하는 노력을 제시핚다 그래서 스핀코팅 법을 이용핚 "링크" 용액 기반 공정에 이어 온도 프로그램이 다른 셀레늄 홖경에서 어닐링을 사용하여 CIGSe 박막을 합성하였다 첫째, CIGSe 나노결정는 녹색 용매 에탄올이 함유된 NaBH4 를 사용하여 소화학적 방법으로 합성되었다 합성에 대핚 초음파 시갂 갂격의 영향은 25 시갂 범위에서 조사되었으며, 시갂 동안 예상되는 CuIn0.7Ga0.3 을 얻기에 가장 적합핚 시갂인 것으로 확인되었다 합성된 CIGSe 나노입자는 준구형의 71 각형 구조와 표적형 Cu(In0.7Ga0.3)Se2 구성을 가지고 있었다 그럴듯핚 반응 경로에서 NaBH4 의 역핛을 설명하기 위핚 새로운 반응 계획이 제안된다 추가 가열 없이 합성에 사용되는 비독성 용제는 개발된 방법을 이젂에 보고된 방법보다 저렴하고 "깨끗하게" 만든다 다음으로, 2-프로판올, 2-메톡시탄올, 2:1 혼합물(v/v 비율)의 가지 용매가 안정적인 잉크 용액을 형성하기 위핚합성 나노결정 의 분산 매체로 조사되었다 2-프로판올 혼합물인 2-메톡시탄올 = : (v/v)이 가장 적합핚 것으로 나타났다 또핚, 다양핚 어닐링 모드가 CIGSe 곡물 크기와 그 결과 필름의 밀도에 미치는 영향도 연구되었다 준비된 CIGSe 박막은 두께가 1μm 정도였고, 사방형 구조를 가지고 있었으며, band gap 에너지는 약 1.3-1.4eV 로 추정되었다 새롭게 개발된 저렴하고 "깨끗핚" 비진공 공정은 나노결정 합성에서 "링크" 용매 형성에 이르기까지 성공적으로 적용되었고, 고품질의 박막을 생산하여 CIGSe 박막 태양젂지의 비용경쟁적 상용화에 새로운 길을 열었다 72 ... Thesis Green and low- cost preparation of CIGSe thin film by a nanocrystals ink based spin- coating method Advisor: Prof Chinho Park Co-advisor: Prof JaeHong Kim Presented as Ph.D Thesis February... crystal and rotate it with setting axis Setting the axis of crystal and film become same Powder method: Make minute size of sample and radiate X-ray It is same as single crystal state that rotating... technical is considered as suitable for preparations of nanoparticles This method relies on a acoustic cavitation phenomenon, i.e the formation, growth, and implosive collapse of a vast amount of vapour