İki aşamalı yöntem ile CZTS ince filmlerinin esnek Cu-folyo altlık üzerine büyütülmesi

Yıl 2024, , 826 - 834, 15.07.2024

Mehmet Ali Olğar , Recep Zan

https://doi.org/10.28948/ngumuh.1462925

Öz

Bu araştırmada, farklı sülfürleme süreleri ile esnek Cu-folyo üzerine büyütülmüş CZTS ince filmler incelendi. X-ışını kırınımı (XRD), Raman spektroskopisi, Enerji Dağılımlı X-ışını spektroskopisi (EDX), Taramalı Elektron Mikroskopisi (SEM), optik geçirgenlik ve fotolüminesans (PL) ölçümleri de dahil olmak üzere çeşitli karakterizasyon yöntemleri kullanıldı. XRD analizinde kesterit CZTS fazına özgü belirgin kırınım pikleri 2θ= 28.45° (112), 47° (220/204) ve 56° (312/116) civarında meydana gelen pikler gözlemlendi. Ayrıca, Cu2S ve SnS gibi bazı ikincil fazlar tespit edildi. Raman spektroskopisi, kesterit CZTS fazının varlığını doğruladı ve kesterit yapısı içindeki kükürt atomu titreşimlerine atfedilen yaklaşık ~336 cm-1'de belirgin bir pik tespit edildi. CZTS yapısının yanı sıra, Cu2SnS3 (CTS) fazının varlığını işaret eden az sayıda pik de tespit edildi. EDX analizi, tüm örneklerin Cu-fakiri ve Zn-zengini kompozisyona sahip olduğunu göstermiştir. Farklı büyütme oranlarında yapılan SEM görüntülemeleri yüzey morfolojisinde ve tane yapılarında değişiklikler olduğunu gösterdi. 30 ve 60 saniye süreyle sülfürlenmiş filmler taneli bir yapı morfolojisi sergilerken, bekleme süresini 120 saniyeye uzatmak daha kompakt bir yüzey morfolojisine katkı sağladığı tespit edilmiştir. Optik bant aralığı değerleri 1.57 ile 1.60 eV arasında değişkenlik göstermiştir. PL ölçümleri, tüm örneklerde 1.25 eV civarında güçlü bir PL emisyonu sergiledi ve bu, CZTS yapısı içindeki çeşitli geçişlere atfedildi. PL ölçümlerinde gözlemlenen banttan banta geçişlerinin olmaması, CZTS içindeki özden kusur seviyeleri ve rekombinasyon merkezlerinin varlığını işaret ettiği belirlenmiştir. Genel olarak, bu çalışmada CZTS ince filmlerin kısa sülfürleme süreleriyle esnek Cu-folyolar üzerine üretilebileceği ve bu sayede CZTS ince film güneş pillerinin uygulama alanlarının genişletilebileceği gösterilmiştir.

Anahtar Kelimeler

CZTS ince film, Cu-folyo, Saçtırma, RTP, Kısa sülfürleme süresi

Destekleyen Kurum

TÜBİTAK

Teşekkür

The authors gratefully acknowledge the funding from The Scientific and Technological Research Council of Turkey (TÜBİTAK-120F275).

Fabrication of CZTS thin film on flexible Cu-foil substrate by two-stage process

Öz

In this research, CZTS thin films were grown on flexible Cu-foil substrates with varying sulfurization times. Distinct characterization methods were employed, including X-ray diffraction (XRD), Raman spectroscopy, Energy-Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM), optical transmission, and Photoluminescence (PL) measurements. Distinctive diffraction peaks characteristic of the kesterite CZTS phase were observed in the XRD analysis, occurring around at 2θ= 28.45° (112), 47° (220/204), and 56° (312/116). Additionally, some secondary phases such as Cu2S and SnS were identified. Raman spectroscopy confirmed the presence of the kesterite CZTS phase, with a prominent peak detected at approximately ~336 cm-1, attributed to sulfur atom vibrations within the kesterite structure. Apart from CZTS structure, minor peaks suggesting the presence of the Cu2SnS3 (CTS) phase was detected. EDX analysis revealed compositions with Cu-poor content and Zn-rich content across all samples, with slight variations in sulfurization dwell times affecting the chemical composition. SEM imaging at different magnifications showed alterations in surface morphology and grain structures. Films sulfurized for 30 s and 60 s displayed a granular structure morphology, while extending the dwell time to 120 s resulted in a more compact surface morphology. Optical band gap values ranged between 1.57 and 1.60 eV. PL measurements consistently exhibited strong PL emission around 1.25 eV for all samples, attributed to various transitions within the band structure of CZTS film. The absence of observable band-to-band transitions in the PL measurements indicated the presence of intrinsic defect levels and recombination centers within CZTS. Overall, it was demonstrated in this study that CZTS thin films can be produced on flexible Cu-foils with short sulfurization times, thereby expanding the application areas of CZTS thin-film solar cells.

Anahtar Kelimeler

CZTS thin film, Cu-foil, Sputtering, RTP, Short sulfurization time

Kaynakça

• A. Luque and S. Hegedus, Handbook of photovoltaic science and engineering, John Wiley & Sons, 2011.
• H. Katagiri, N. Ishigaki, T. Ishida and K. Saito, Characterization of Cu2ZnSnS4 thin films prepared by vapor phase sulfurization, Japanese Journal of Applied Physics, 40, 500, 2001. https://doi.org/10.1143/JJAP.40.500.
• W. Shockley and H.J. Queisser, Detailed balance limit of efficiency of p‐n junction solar cells, 32, 510-519, 1961.
• Y. Gong, Q. Zhu, B. Li, S. Wang, B. Duan, L. Lou, C. Xiang, E. Jedlicka, R. Giridharagopal and Y. Zhou, Elemental de-mixing-induced epitaxial kesterite/CdS interface enabling 13%-efficiency kesterite solar cells, Nature Energy, 1-12, 2022. https://doi.org/10.1038/s41560-022-01132-4
• J. Jiang, L. Zhang, W. Wang and R. Hong, The role of sulphur in the sulfurization of CZTS layer prepared by DC magnetron sputtering from a single quaternary ceramic target, Ceramics International, 44, 11597-11602, 2018. https://doi.org/10.1016/j.ceramint.2018.03.225
• N. Akcay, E. Zaretskaya and S. Ozcelik, Development of a CZTS solar cell with CdS buffer layer deposited by RF magnetron sputtering, Journal of Alloys and Compounds, 772, 782-792, 2019. https://doi.org/10.1016/j.jallcom.2018.09.126.
• M.A. Olgar, A. Seyhan, A.O. Sarp and R. Zan, The choice of Zn or ZnS layer in the stacked precursors for preparation of Cu2ZnSnS4 (CZTS) thin films, Superlattice Microst, 146, 106669, 2020. https://doi.org/10.1016/j.spmi.2020.106669.
• E. Garcia-Llamas, J. Merino, R. Gunder, K. Neldner, D. Greiner, A. Steigert, S. Giraldo, V. Izquierdo-Roca, E. Saucedo and M. León, Cu2ZnSnS4 thin film solar cells grown by fast thermal evaporation and thermal treatment, Solar Energy, 141, 236-241, 2017. https://doi.org/10.1016/j.solener.2016.11.035.
• A. Lokhande, R. Chalapathy, J. Jang, P. Babar, M. Gang, C. Lokhande and J.H. Kim, Fabrication of pulsed laser deposited Ge doped CZTSSe thin film based solar cells: Influence of selenization treatment, Solar Energy Materials and Solar Cells, 161, 355-367, 2017. https://doi.org/10.1016/j.solmat.2016.12.016.
• M. Azim-Araghi and N. Safaie, Structural, optical and electrical properties of Cu2ZnSnS4 thin film deposited by electron beam evaporation method, Optik, 258, 168936, 2022. https://doi.org/10.1016/j.ijleo.2022.168936.
• H. Xin, J.K. Katahara, I.L. Braly and H.W. Hillhouse, 8% Efficient Cu2ZnSn(S,Se)4 solar cells from redox equilibrated simple precursors in DMSO, Advanced Energy Materials, 4, 1301823, 2014. https://doi.org/10.1002/aenm.201301823.
• A. Ziti, B. Hartiti, H. Labrim, S. Fadili, H.J. Tchognia Nkuissi, A. Ridah, M. Tahri and P. Thevenin, Effect of copper concentration on physical properties of CZTS thin films deposited by dip-coating technique, Applied Physics A, 125, 1-9, 2019. https://doi.org/10.1007/s00339-019-2513-0.
• M. Courel, E. Valencia-Resendiz, J. Andrade-Arvizu, E. Saucedo and O. Vigil-Galán, Towards understanding poor performances in spray-deposited Cu2ZnSnS4 thin film solar cells, Solar energy materials and solar cells, 159, 151-158, 2017. https://doi.org/10.1016/j.solmat.2016.09.004.
• C. Chan, H. Lam and C. Surya, Preparation of Cu2ZnSnS4 films by electrodeposition using ionic liquids, Solar Energy Materials and Solar Cells, 94, 207-211, 2010. https://doi.org/10.1016/j.solmat.2009.09.003.
• S. Alamri, Effect of Working Pressure on the Composition of a Cu2ZnSnS4 Thin Film Deposited by RF Sputtering of a Single Target, Arabian Journal for Science and Engineering, 1-8, 2022. https://doi.org/10.1007/s13369-022-06991-3.
• A. Moholkar, S. Shinde, G.L. Agawane, S. Jo, K. Rajpure, P. Patil, C. Bhosale and J. Kim, Studies of compositional dependent CZTS thin film solar cells by pulsed laser deposition technique: An attempt to improve the efficiency, Journal of Alloys and Compounds, 544, 145-151, 2012. https://doi.org/10.1016/j.jallcom.2012.07.108.
• M.A. Olgar, S. Erkan and R. Zan, Dependence of CZTS thin film properties and photovoltaic performance on heating rate and sulfurization time, J Alloy Compd, 963, 171283, 2023. https://doi.org/10.1016/j.jallcom.2023.171283.
• O.P. Singh, A. Sharma, K. Gour, S. Husale and V. Singh, Fast switching response of Na-doped CZTS photodetector from visible to NIR range, Solar Energy Materials and Solar Cells, 157, 28-34, 2016. https://doi.org/10.1016/j.solmat.2016.04.058.
• A. Migdadi, F.Y. Alzoubi, H. Al-Khateeb and M. Alqadi, Structural and optoelectronic characterization of synthesized undoped CZTS and Cd-doped CZTS thin films, 60, 138-149, 2022. https://doi.org/10.56042/ijpap.v60i2.54638.
• K. Kaur, K. Arora, B. Behzad, Q. Qiao and M. Kumar, Nanoscale charge transport and local surface potential distribution to probe defect passivation in Ag doped Cu2ZnSnS4 absorbing layer, Nanotechnology, 30, 065706, 2018. https://doi.org/10.1088/1361-6528/aaf185.
• S. Englund, Alternative back contacts for CZTS thin film solar cells, in, Acta Universitatis Upsaliensis, 2020.
• E. Ojeda-Durán, K. Monfil-Leyva, J. Andrade-Arvizu, I. Becerril-Romero, Y. Sánchez, R. Fonoll-Rubio, M. Guc, Z. Jehl, J. Luna-López and A. Muñoz-Zurita, CZTS solar cells and the possibility of increasing VOC using evaporated Al2O3 at the CZTS/CdS interface, Solar Energy, 198, 696-703, 2020. https://doi.org/10.1016/j.solener.2020.02.009.
• M. Vishwakarma, N. Thota, O. Karakulina, J. Hadermann and B. Mehta, Role of graphene inter layer on the formation of the MoS2-CZTS interface during growth, in: AIP Conf. Proc., AIP Publishing LLC, 1953 100064, 2018. https://doi.org/10.1063/1.5033000.
• J. He, L. Sun, K. Zhang, W. Wang, J. Jiang, Y. Chen, P. Yang and J. Chu, Effect of post-sulfurization on the composition, structure and optical properties of Cu2ZnSnS4 thin films deposited by sputtering from a single quaternary target, Applied Surface Science, 264, 133-138, 2013. https://doi.org/10.1016/j.apsusc.2012.09.140.
• M.A. Olgar, A. Seyhan, A.O. Sarp and R. Zan, Impact of sulfurization parameters on properties of CZTS thin films grown using quaternary target, J Mater Sci-Mater El, 31, 20620-20631, 2020. https://doi.org/10.1007/s10854-020-04582-2.
• M.A. Olgar, Enhancement in photovoltaic performance of CZTS Thin-film solar cells through varying stacking order and sulfurization time, J Mater Sci-Mater El, 33, 20121-20133, 2022. https://doi.org/10.1007/s10854-022-08829-y.
• J. Ajayan, D. Nirmal, P. Mohankumar, M. Saravanan, M. Jagadesh and L. Arivazhagan, A review of photovoltaic performance of organic/inorganic solar cells for future renewable and sustainable energy technologies, Superlattices and Microstructures, 143, 106549, 2020. https://doi.org/10.1016/j.spmi.2020.106549.
• K. Ahn, S.-Y. Kim, S. Kim, D.-H. Son, S.-H. Kim, S. Kim, J. Kim, S.-J. Sung, D.-H. Kim and J.-K. Kang, Flexible high-efficiency CZTSSe solar cells on stainless steel substrates, Journal of Materials Chemistry A, 7, 24891-24899, 2019. https://doi.org/10.1039/C9TA08265D.
• Q. Tian, X. Xu, L. Han, M. Tang, R. Zou, Z. Chen, M. Yu, J. Yang and J. Hu, Hydrophilic Cu 2 ZnSnS 4 nanocrystals for printing flexible, low-cost and environmentally friendly solar cells, CrystEngComm, 14, 3847-3850, 2012. https://doi.org/10.1039/C2CE06552E.
• L. Sun, H. Shen, H. Huang, A. Raza, Q. Zhao and J. Yang, Influence of Ge layer location on performance of flexible CZTSSe thin film solar cell, Vacuum, 165, 186-192, 2019. https://doi.org/10.1016/j.vacuum.2019.04.026.
• Y. Zhang, Q. Ye, J. Liu, H. Chen, X. He, C. Liao, J. Han, H. Wang, J. Mei and W. Lau, Earth-abundant and low-cost CZTS solar cell on flexible molybdenum foil, Rsc Advances, 4, 23666-23669, 2014. https://doi.org/10.1039/C4RA02064B.
• C.-Y. Peng, T.P. Dhakal, S. Garner, P. Cimo, S. Lu and C.R. Westgate, Fabrication of Cu2ZnSnS4 solar cell on a flexible glass substrate, Thin Solid Films, 562, 574-577, 2014. https://doi.org/10.1016/j.tsf.2014.03.054.
• I. Becerril‐Romero, L. Acebo, F. Oliva, V. Izquierdo‐Roca, S. López‐Marino, M. Espíndola‐Rodríguez, M. Neuschitzer, Y. Sánchez, M. Placidi and A. Pérez‐Rodríguez, CZTSe solar cells developed on polymer substrates: Effects of low‐temperature processing, Progress in Photovoltaics: Research and Applications, 26, 55-68, 2018. https://doi.org/10.1002/pip.2945.
• M. Insider, Price of Metals, 2023.
• M. Ohring, Engineering materials science, Elsevier, 1995.
• P. Desai, T. Chu, H.M. James and C. Ho, Electrical resistivity of selected elements, Journal of physical and chemical reference data, 13, 1069-1096, 1984. https://doi.org/10.1063/1.555723.
• ThoughtCo., Table of Electrical Resistivity and Conductivity, 2023.
• S. Zee, Physics of semiconductor devices/In 2 books. Book. 1. Per. from English.-2nd revision. and additional ed, M.: Mir, 1984.
• A. Kumar and A.D. Thakur, Role of contact work function, back surface field, and conduction band offset in Cu2ZnSnS4 solar cell, Japanese Journal of Applied Physics, 57, 08RC05, 2018. https://doi.org/10.7567/JJAP.57.08RC05.
• T. Jäger, Y.E. Romanyuk, B. Bissig, F. Pianezzi, S. Nishiwaki, P. Reinhard, J. Steinhauser, J. Schwenk and A.N. Tiwari, Improved open-circuit voltage in Cu (In, Ga) Se2 solar cells with high work function transparent electrodes, Journal of Applied Physics, 117, 2015. https://doi.org/10.1063/1.4922351.
• B. Theler, S.K. Kauwe and T.D. Sparks, Materials Abundance, Price, and Availability Data from the Years 1998 to 2015, Integrating Materials and Manufacturing Innovation, 9, 144-150, 2020. https://doi.org/10.1007/s40192-020-00173-5.
• U. Ugur and G. Elert, Resistivity of steel, in: The physics factbook, School Sci., 2006.
• L. MatWeb, Material property data, MatWeb,[Online]. Available: http://www. matweb. com, 2016.
• J. Hölzl and F.K. Schulte, Work function of metals, Solid surface physics, 1-150, 2006.
• B. Singh and B. Mehta, Relationship between nature of metal-oxide contacts and resistive switching properties of copper oxide thin film based devices, Thin Solid Films, 569, 35-43, 2014. https://doi.org/10.1016/j.tsf.2014.08.030
• Best Research-Cell Efficiency chart, regularly updated by NREL, http://www.nrel.gov/ncpv/images/efficiency_chart.jpg, 2021.
• E. ToolBox, Thermal Expansion - Linear Expansion Coefficients, 2023.
• S. Chen, A. Walsh, X.G. Gong and S.H. Wei, Classification of lattice defects in the kesterite Cu2ZnSnS4 and Cu2ZnSnSe4 earth-abundant solar cell absorbers, Adv Mater, 25, 1522-1539, 2013. https://doi.org/10.1002/adma.201203146
• H.R. Jung, S.W. Shin, K. Gurav, M. Suryawanshi, C.W. Hong, H.S. Yang, J.Y. Lee, J.H. Moon and J.H. Kim, Phase evolution of Cu2ZnSnS4 (CZTS) kesterite thin films during the sulfurization process, Ceramics International, 41, 13006-13011, 2015. https://doi.org/10.1016/j.ceramint.2015.06.145.
• Y. Wei, D. Zhuang, M. Zhao, Q. Gong, R. Sun, G. Ren, Y. Wu, L. Zhang, X. Lyu and X. Peng, An investigation on the relationship between open circuit voltage and grain size for CZTSSe thin film solar cells fabricated by selenization of sputtered precursors, Journal of alloys and compounds, 773, 689-697, 2019. https://doi.org/10.1016/j.jallcom.2018.09.258.
• B.G. Mendis, M.C. Goodman, J.D. Major, A.A. Taylor, K. Durose and D.P. Halliday, The role of secondary phase precipitation on grain boundary electrical activity in Cu2ZnSnS4 (CZTS) photovoltaic absorber layer material, Journal of applied physics, 112, 124508, 2012. https://doi.org/10.1063/1.4769738
• M.A. Olgar, B.M. Basol, M. Tomakin and E. Bacaksiz, Phase transformation in Cu2SnS3 (CTS) thin films through pre-treatment in sulfur atmosphere, J Mater Sci-Mater El, 32, 10018-10027, 2021. https://doi.org/10.1007/s10854-021-05660-9
• P. Fernandes, P. Salomé and A. Da Cunha, Study of polycrystalline Cu2ZnSnS4 films by Raman scattering, Journal of alloys and compounds, 509, 7600-7606, 2011. https://doi.org/10.1016/j.jallcom.2011.04.097
• M. Guc, S. Levcenko, I.V. Bodnar, V. Izquierdo-Roca, X. Fontane, L.V. Volkova, E. Arushanov and A. Pérez-Rodríguez, Polarized Raman scattering study of kesterite type Cu2ZnSnS4 single crystals, Scientific reports, 6, 1-7, 2016. https://doi.org/10.1038/srep19414
• P. Prabeesh, V. Sajeesh, I.P. Selvam, M.D. Bharati, G.M. Rao and S.J.S.E. Potty, CZTS solar cell with non-toxic buffer layer: A study on the sulphurization temperature and absorber layer thickness, 207, 419-427, 2020. https://doi.org/10.1016/j.solener.2020.06.103
• M.Y. Valakh, O. Kolomys, S. Ponomaryov, V. Yukhymchuk, I. Babichuk, V. Izquierdo‐Roca, E. Saucedo, A. Perez‐Rodriguez, J.R. Morante, S. Schorr and I. V. Bodnar, Raman scattering and disorder effect in Cu2ZnSnS4, 7, 258-261, 2013. https://doi.org/10.1002/pssr.201307073
• X. Liu, X. Li, X. Li, Q. Li, D. Zhang, N. Yu and S. Wang, Fabrication of Cu2SnS3 thin film solar cells via a sol-gel technique in air, Physica B: Condensed Matter, 627, 413613, 2022. https://doi.org/10.1016/j.physb.2021.413613
• M.A. Olgar, Improvement in the structural and optical properties of Cu2SnS3 (CTS) thin films through soft-annealing treatment, Superlattice Microst, 138, 106366, 2020. https://doi.org/10.1016/j.spmi.2019.106366
• J. Pankove, Photoelectric Emission, Optical Processes in Semiconductors, Dover Publications Inc., New York, 287, 301, 1971.
• J. Tauc, Optical properties and electronic structure of amorphous Ge and Si, Mater. Res. Bull., 3, 37-46, 1968. https://doi.org/10.1016/0025-5408(68)90023-8
• W. Wang, M.T. Winkler, O. Gunawan, T. Gokmen, T.K. Todorov, Y. Zhu and D.B. Mitzi, Device characteristics of CZTSSe thin‐film solar cells with 12.6% efficiency, Advanced energy materials, 4, 1301465, 2014. https://doi.org/10.1002/aenm.201301465.
• C. Kim and S. Hong, Band gap shift of Cu2ZnSnS4 thin film by residual stress, Journal of Alloys and Compounds, 799, 247-255, 2019. https://doi.org/10.1016/j.jallcom.2019.05.290
• S. Chen, X.-G. Gong, A. Walsh and S.-H. Wei, Structural, electronic and defect properties of Cu2ZnSn (S, Se) 4 alloys, MRS Online Proceedings Library (OPL), 1370, 2011. https://doi.org/10.1557/opl.2011.764
• D. Han, Y. Sun, J. Bang, Y. Zhang, H.-B. Sun, X.-B. Li and S.J.P.R.B. Zhang, Deep electron traps and origin of p-type conductivity in the earth-abundant solar-cell material Cu2ZnSnS4, 87, 155206, 2013. https://doi.org/10.1103/PhysRevB.87.155206.