Sol-jel Yöntemi ile Kaplanan Nb2O5 İnce Filmlerin Karakterizasyonu

Yıl 2020, Cilt: 6 Sayı: 1, 49 - 56, 22.05.2020

Tuğçe Ataşer

https://doi.org/10.28979/comufbed.595184

Öz

Bu çalışmada, hazırlanan niobyum pentoksit (Nb2O5) çözeltileri farklı sürelerde ve aynı koşullar altında yaşlandırıldı. Nb2O5 ince filmler, soda kireç cam ve silisyum alttaşlar üzerine aynı koşullar altında döndü-rerek kaplama cihazında sol-jel yöntemi ile kaplandı. Kaplanan Nb2O5 ince filmlerin yapısal ve optik özel-likleri ile yüzey morfolojilerinin çözeltinin yaşlanmasına olan bağımlılığı sırasıyla, X-ışını kırınımı (XRD), ikincil iyon kütle spektrometresi (SIMS), UV-Vis spektrofotometre ve atomik kuvvet mikroskobu (AFM) analizleri ile incelendi. XRD sonuçlarından, SG-1 (1 gün yaşlandırılan çözelti ile kaplanan film) numunesi-nin kristal yapıya sahip olduğu görüldü ve SG-1 numunesinin tanecik boyutu 46,12 nm olarak hesaplandı. SIMS analizi ile niobyum (Nb) ve oksijen (O) atomik türlerinin film derinliği boyunca homojen olarak dağıldığı tespit edildi. SG-1 numunesi görünür bölgede %80 civarında geçirgenliğe sahiptir ve soğurma spektrumundan elde edilen yasak enerji aralığı yaklaşık 3,65 eV olarak bulundu. Çözeltilerin yaşlandırılma süreleri artıkça, yansıtma değerleri kullanılarak hesaplanan kırılma indislerinin azaldığı görülmektir. AFM sonuçlarından, 5x5 µm2’lik alanda taranan yüzey görüntülerinden SG-1 numunesinin düzgün yüzey mor-folojisine ve 70 nm tanecik büyüklüğüne sahip olduğu görülmektedir. Ayrıca, AFM görüntülerinden çözelti yaşlandıkça RMS değerlerinin artığı görülmektedir. Elde edilen sonuçlar; Nb2O5 çözeltisinin yaşlandırılma süresinin kaplanan filmlerin yapısal, optik ve yüzey morfolojisini etkilediğini göstermektedir. Kaplanan Nb2O5 ince filmlerin Si temelli güneş hücrelerinde yansıma önleyici tabaka olarak kullanılması önerilmektedir.

Anahtar Kelimeler

Nb2O5, ince film, sol-jel, döndürerek kaplama, yaşlandırma, yaşlandırma

Destekleyen Kurum

CSBB

Proje Numarası

2016K121220

Teşekkür

Bu çalışma CSBB tarafından 2016K121220 nolu proje ile desteklenmiştir.

Characterization of Nb2O5 Thin Films Coated by Sol-gel Method

Öz

In this study, prepared niobium pentoxide (Nb2O5) solutions were aged for different times and under the same conditions. Nb2O5 thin films were deposited on the soda lime glass and silicon (Si) substrates under the same conditions by sol-gel spin coating method. The structural and optical properties and surface morphologies of the coated Nb2O5 thin films depending on the solution ageing were investigated by X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), UV-Vis spectrometer and atomic force mi-croscopy (AFM) analyzes, respectively. XRD results indicated that SG-1 sample (the film deposited using 1-day aged solution) had crystal structure and the particle size of the SG-1 sample was calculated as 46.12 nm. It was determined by SIMS analysis that the niobium (Nb) and oxygen (O) atomic species distributed homogeneously along the film depth. The SG-1 sample had 80% optical transmittance in the visible region and the energy band gap from the absorption spectrum was found to be about 3.65 eV. It was seen from the AFM surface images scanned in 5x5 µm2 area that SG-1 sample had smoother surface morphology with particle size value calculated as 70 nm. Also, it was seen from the AFM images that the RMS values increase as the solution ageing. The obtained results showed that the ageing time of Nb2O5 solution affects the structural, optical and surface morphology of the deposited films. It is suggested that the coated Nb2O5 thin films should be used as antireflective layer in crystal Si based solar cells.

Anahtar Kelimeler

Nb2O5, thin film, sol-gel, spin coating, ageing

Proje Numarası

2016K121220

Kaynakça

• Aegerter M. A. (2001). Sol-Gel Niobium Pentoxide: A Promising Material for Electrochromic Coatings, Batteries, Nanocrystalline Solar Cells and Catalysis. Solar Energy Materials Solar Cells (68), 401-422. Erişim adresi: https://doi.org/10.1016/S0927-0248(00)00372-X
• Agarwal G. ve Reddy G. B. (2005). Study of Surface Morphology and Optical Properties of Nb2O5 Thin Films with Annealing. Journal of Materials Science: Materials in Electronics (16), 21–24. Erişim adresi: https://link.springer.com/content/pdf/10.1007%2Fs10854-005-4953-x.pdf
• Bahuguna G. Mishra N.K. Chaudhary P. Kumar A. ve Singh R. (2016). Thin Film Coating through Sol-Gel Technique. Research Journal of Chemical Sciences 6(7), 65-72. Erişim adresi: https://www.researchgate.net/publication/314093443
• Casey H. C. Sell D.D. ve Panish M.B. (1974). Refractive index of AlxGa1−xAs between 1.2 and 1.8 eV. Appl. Phys. Lett (24), 63-65. Erişim adresi: https://doi.org/10.1063/1.1655095
• Cha J.-H. Ashok K. Kissinger N.J. S. Ra Y.-H. Sim J.-K. Kim J.-S. ve Lee C.-R. (2011). Effect of Thermal Annealing on the Structure, Morphology, and Electrical Properties of Mo Bottom Electrodes for Solar Cell Applications. Journal of the Korean Physical Society (59), 2280-2285. Erişim adresi: https://doi.org/10.3938/jkps.59.2280.
• Chen K.-N. Hsu C.-M. Li J. Liou Y.-C. ve Yang C.-F. (2016). Investigation of Antireflection Nb2O5 Thin Films by the Sputtering Method under Different Deposition Parameters. Micromachines 7(151), 2-12. Erişim adresi: https://doi.org/10.3390/mi7090151
• Danish M. ve Pandey A. (2016). Influence of Thickness and Calcination under Ammonia Gas Flow on Topographical, Optical and Photocatalytic Properties of Nb2O5 Thin Films Prepared by Sol–Gel: A Comparative Study. Mater Sci: Mater Electron (27), 6939–6946. Erişim adresi: https://doi.org/10.1007/s10854-016-4648-5
• Dash J.K. Chen L. Topka M.R. Dinolfo P.H. Zhang L.H. Kisslinger K. Lua T.-M. ve Wanga G.-C. (2015). A Simple Growth Method for Nb2O5 Films and Their Optical Properties, RSC Adv., (5), 36129–36139. Erişim adresi: https://doi.org/10.1039/C5RA05074J
• Fang S.J. Haplepete S. Chen W. ve Helms C.R. (1997). Analyzing atomic force microscopy images using spectral methods. Journal of Applied Physics, (82), 5891-5898. Erişim adresi: https://doi.org/10.1063/1.366489
• Friedbacher G. ve Bubert H. (2016). Surface and Thin Film Analysis: A Compendium of Principles, Instrumentation, and Applications. Wiley-VCH part 1, page 11.
• Georgiev R. Georgieva B. Vasileva M. Ivanov P. ve Babeva T, (2015). Optical Properties of Sol-Gel Nb2O5 Films with Tunable Porosity for Sensing Applications. Advances in Condensed Matter Physics, (2015), 1-8. Erişim adresi: http://dx.doi.org/10.1155/2015/403196
• Hall D. B. ve Underhill P. (1998). Spin Coating of Thin and Ultrathin Polymer Films. Polymer Engineering and Science (38), 2039-2045. Erişim adresi: https://doi.org/10.1002/pen.10373
• Lazarova K. Vasileva M. Marinov G. ve Babeva T. (2014). Optical Characterization of Sol–Gel Derived Nb2O5 Thin Films. Optics Laser Technology (58), 114–118. Erişim adresi: https://doi.org/10.1016/j.optlastec.2013.11.014
• Lazarova K. Vasileva M. Marinov G. ve Babeva T. (2013). Sol-Gel Derived Nb2O5 Thin Films for Photonic Applications. Bulgarian Chemical Communications, (45), 23-27. Erişim adresi: https://www.researchgate.net/publication/259468977
• Livage J. ve Ganguli D. (2001). Sol-Gel Electrochromic Coatings and Devices: A Review. Solar Energy Materials Solar Cells (68), 365-381. Erişim adresi: https://doi.org/10.1016/S0927-0248(00)00369-X
• Ozer N. Barreto T. Büyüklimanli T. ve Lampert C.M. (1995). Characterization of Sol-Gel Deposited Niobium Pentoxide Films for Electrochromic Devices. Solar Energy Materials and Solar Cells (36), 433-443. Erişim adresi: https://doi.org/10.1016/0927-0248(94)00197-9
• Ozer N. Chen D.-G. ve Lampert C.M. (1996). Preparation and Properties of Spin-Coated Nb2O5 Films by The Sol-Gel Process for Electrochromic Applications. Thin Solid Films (277), 162-168. Erişim adresi: https://pdf.sciencedirectassets.com/271603/1-s2.0-S0040609099X00009/
• Pehlivan E. Tepehan F. Z. ve Tepehan G. G. (2003). Comparison of Optical, Structural and Electrochromic Properties of Undoped and WO3-Doped Nb2O5. Solid State Ionics (165), 105-110. Erişim adresi: https://doi.org/10.1016/j.ssi.2003.08.021
• Rabaa A.M. Bautista-Ruíza J.ve Joya M.R. (2015). Synthesis and Structural Properties of Niobium Pentoxide Powders: A Comparative Study of the Growth Process. Materials Research 1-7. Erişim adresi: http://dx.doi.org/10.1590/1980-5373-MR-2015-0733
• Sancho-Parramon J. Janicki V. ve Zorc H. (2008). Compositional Dependence of Absorption Coefficient and Band-Gap for Nb2O5–SiO2 Mixture Thin Films. Thin Solid Films (516), 5478–5482. Erişim adresi: http://dx.doi.org/10.1016/j.tsf.2007.07.028
• Wood D. L. ve Tauc L. (1972). Weak absorption tails in amorphous semiconductors. Physical Review B (5), 3144-3151. Erişim adresi: https://doi.org/10.1103/PhysRevB.5.3144