Tailoring the Optical and Electrical Properties of ZnO Films: Co-Doping with F and In

Abstract

In this study, undoped ZnO, 3% In doped ZnO and 5% F: 3% In co-doped ZnO films were successfully synthesized via ultrasonic spray pyrolysis. The study objective is to investigate the changes in physical properties especially opto-electrical of ZnO films with F:In co-doping strategy and thus contribute to developing high-performance materials for opto-electronic devices. Structural analysis showed that obvious changes occurred in the ZnO crystal structure with doping and the dopant atoms were successfully integrated into the ZnO lattice. Morphological studies showed that 5% F: 3% In co-doped ZnO films exhibit a homogeneous, nanostructured, and compact surface, with surface roughness being lower than undoped ZnO films. Moreover, SEM images identified granular nanostructures in 3% In doped and 5% F: 3% In co-doped ZnO films, which were attributed to the stabilization of grain boundaries by dopant atoms, promoting a uniform structure. Optical analysis revealed that the 5% F: 3% In co-doped ZnO film exhibited a transmittance of 83% in the visible region and a wider optical band gap of 3.32 eV compared to other films. Electrical characterization demonstrated that the carrier concentration of ZnO films was 1.031017 cm-3, increasing markedly to 1.141018 cm-3 in 5% F: 3% In co-doped ZnO film. Additionally, the resistivity of the 5% F: 3% In co-doped ZnO film was detected at the lowest level of 1.6510-1 cm. This data reveals the potential of 5% F: 3% In co-doped ZnO films for advanced opto-electronic applications, including photovoltaic cells, display technologies, and LEDs. Co-doping ZnO films with fluorine and indium emerge as a promising strategy to enhance electrical and optical properties.

Keywords

• Ultrasonic Spray Pyrolysis
• TCO Materials
• Optical Properties
• Electrical Properties
• F:In Co-doped ZnO

Ethical Statement

The author of this article declares that the materials and methods they use in their work do not require ethical committee approval and/or legal-specific permission.

Thanks

I would like to thank Assoc. Prof. Dr. Emrah SARICA, faculty member of the Electrical and Electronics Engineering Department of Başkent University, for providing laboratory facilities and support in conducting the Hall effect measurements.

ZnO Filmlerin Optik ve Elektriksel Özelliklerinin Düzenlenmesi: F ve In ile Eş-Katkılama

Abstract

Bu çalışmada, katkısız ZnO, %3 In katkılı ZnO ve %5 F: %3 In eş-katkılı ZnO filmleri ultrasonik sprey pirolizi ile başarıyla sentezlendi. Çalışmanın amacı, F:In eş-katkılama stratejisi ile ZnO filmlerinin fiziksel özelliklerindeki (özellikle opto-elektriksel) değişimleri incelemek ve böylece opto-elektronik cihazlar için yüksek performanslı malzemeler geliştirmeye katkıda bulunmaktır. Yapısal analiz, katkılama ile ZnO kristal yapısında belirgin değişimler meydana geldiğini ve katkı atomlarının ZnO örgüsüne başarıyla entegre olduğunu göstermiştir. Morfolojik çalışmalar, %5 F: %3 In eş-katkılı ZnO filmlerinin homojen, nanoyapılı ve kompakt bir yüzey sergilediğini, yüzey pürüzlülüğünün katkısız ZnO filmlerinden daha düşük olduğunu göstermiştir. Dahası, SEM görüntüleri, katkı atomları tarafından tane sınırlarının stabilizasyonuna atfedilen ve düzgün bir yapıyı destekleyen %3 In katkılı ve %5 F: %3 In eş katkılı ZnO filmlerinde granüler nanoyapıları tanımladı. Optik analiz, %5 F: %3 In eş-katkılı ZnO filminin görünür bölgede %83’lük bir geçirgenlik ve diğer filmlere kıyasla 3.32 eV’lik daha geniş bir optik bant aralığı sergilediğini ortaya koydu. Elektriksel karakterizasyon, ZnO filmlerinin taşıyıcı konsantrasyonunun 1.031017 cm-3 olduğunu, %5 F: %3 In eş-katkılı ZnO filminde 1.141018 cm-3’e belirgin bir şekilde arttığını gösterdi. Ek olarak, %5 F: %3 In eş katkılı ZnO filminin özdirenci en düşük seviyede, 1.6510-1 cm’de tespit edildi. Bu veriler, fotovoltaik hücreler, ekran teknolojileri ve LED’ler dahil olmak üzere gelişmiş opto-elektronik uygulamalar için %5 F: %3 In eş-katkılı ZnO filmlerinin potansiyelini ortaya koymaktadır. ZnO filmlerinin flor ve indiyumla eş-katkılanması, elektriksel ve optik özellikleri geliştirmek için umut verici bir strateji olarak ortaya çıkmaktadır.

Keywords

• Ultrasonik Sprey Piroliz
• TCO Malzemeler
• F:In Eş-katkılı ZnO
• Optik Özellikler
• Elektriksel Özellikler

Ethical Statement

Bu makalenin yazarı çalışmalarında kullandıkları materyal ve yöntemlerin etik kurul izni ve/veya yasal-özel bir izin gerektirmediğini beyan ederler.

Thanks

Hall etkisi ölçümlerinin gerçekleştirilmesinde sağladığı laboratuvar imkânları ve desteği için, Başkent Üniversitesi Elektrik-Elektronik Mühendisliği Bölümü öğretim üyesi Doç. Dr. Emrah Sarıca’ya, teşekkürlerimi sunarım.

References

1. [1] A.H. Ali, Z. Hassan, A. Shuhaimi, Enhancement of optical transmittance and electrical resistivity of post-annealed ITO thin films RF sputtered on Si, Appl. Surf. Sci. 443 (2018) 544–547.
2. [2] H. Liu, H. Li, J. Tao, J. Liu, J. Yang, J. Li, J. Song, J. Ren, M. Wang, S. Yang, X. Song, Y. Wang, Single Crystalline Transparent Conducting F, Al, and Ga Co-Doped ZnO Thin Films with High Photoelectrical Performance, ACS Appl. Mater. Interfaces. 15 (2023) 22195–22203.
3. [3] Ü. Özgür, Y.I. Alivov, C. Liu, A. Teke, M.A. Reshchikov, S. Doǧan, V. Avrutin, S.J. Cho, H. Morko̧, A comprehensive review of ZnO materials and devices, J. Appl. Phys. 98 (2005) 1–103.
4. [4] H. Benali, B. Hartiti, F. Lmai, A. Batan, S. Fadili, P. Thevenin, Synthesis and characterization of Al-doped ZnO thin-films for photovoltaic applications, Mater. Today Proc. (2024).
5. [5] 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 (2015) 55–58.
6. [6] K.M. Kang, Y. Wang, M. Kim, C. Lee, H.H. Park, Al/F codoping effect on the structural, electrical, and optical properties of ZnO films grown via atomic layer deposition, Appl. Surf. Sci. 535 (2021) 147734.
7. [7] B.Y.R.D. Shannon, M. H, N.H. Baur, O.H. Gibbs, M. Eu, V. Cu, Revised Effective Ionic Radii and Systematic Studies of Interatomie Distances in Halides and Chaleogenides, Acta Cryst. A32 (1976) 751–767.
8. [8] T.H. Nguyen, A.T.T. Pham, T.N. Le Pham, T.M. Le, T.T. Duong, D. Van Hoang, K.D. Nguyen, T.D.T. Ung, T.B. Phan, V.C. Tran, Co-doping effects of fluorine and indium on ZnO transparent electrode films, Ceram. Int. 50 (2024) 16698–16703.

9. [9] G. Zheng, J. Song, J. Zhang, J. Li, B. Han, X. Meng, F. Yang, Y. Zhao, Y. Wang, Investigation of physical properties of F-and-Ga co-doped ZnO thin films grown by RF magnetron sputtering for perovskite solar cells applications, Mater. Sci. Semicond. Process. 112 (2020) 105016.
10. [10] F.H. Hsu, N.F. Wang, Y.Z. Tsai, M.C. Chuang, Y.S. Cheng, M.P. Houng, Study of working pressure on the optoelectrical properties of Al-Y codoped ZnO thin-film deposited using DC magnetron sputtering for solar cell applications, Appl. Surf. Sci. 280 (2013) 104–108.
11. [11] G. V. Colibaba, D. Rusnac, V. Fedorov, P. Petrenko, E. V. Monaico, Low-temperature sintering of highly conductive ZnO:Ga:Cl ceramics by means of chemical vapor transport, J. Eur. Ceram. Soc. 41 (2021) 443–450.
12. [12] Y.J. Choi, K.M. Kang, H.H. Park, Anion-controlled passivation effect of the atomic layer deposited ZnO films by F substitution to O-related defects on the electronic band structure for transparent contact layer of solar cell applications, Sol. Energy Mater. Sol. Cells. 132 (2015) 403–409.
13. [13] E.F. Keskenler, G. Turgut, S. Doǧan, Investigation of structural and optical properties of ZnO films co-doped with fluorine and indium, Superlattices Microstruct. 52 (2012) 107–115.
14. [14] A. Hadri, M. Taibi, M. Loghmarti, C. Nassiri, T. Slimani Tlemcąni, A. Mzerd, Development of transparent conductive indium and fluorine co-doped ZnO thin films: Effect of F concentration and post-annealing temperature, Thin Solid Films. 601 (2016) 7–12.
15. [15] L.H. Kathwate, V.D. Mote, Optical and Electrical Properties of In-doped ZnO Films via the Spray Pyrolysis Technique for Optoelectronics Device Applications, J. Electron. Mater. 51 (2022) 6894–6902.
16. [16] I. Gunes, E. Sarica, V. Bilgin, Enhancing Physical Properties: Chromium-Doped Zinc Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis, Tekirdag Namik Kemal Univ. Inst. Nat. Appl. Sci. 2 (2023) 62–70.
17. [17] O.G. Morales-Saavedra, L. Castañeda, J.G. Bañuelos, R. Ortega-Martínez, Morphological, optical, and nonlinear optical properties of fluorine-indium-doped zinc oxide thin films, Laser Phys. 18 (2008) 283–291.
18. [18] I. Gunes, Enhancing π-SnS thin films and fabrication of p-SnS/n-Si heterostructures through flow rate control in ultrasonic spray pyrolysis for improved photovoltaic performance, Appl. Phys. A. 130 (2024) 574.
19. [19] F. Yang, J. Song, X. Chen, X. Lu, J. Li, Q. Xue, B. Han, X. Meng, J. Li, Y. Wang, Ultrasonic spray pyrolysis-induced growth of highly transparent and conductive F, Cl, Al, and Ga co-doped ZnO films, Sol. Energy. 228 (2021) 168–174.
20. [20] T.H. Huang, P.K. Yang, D.H. Lien, C.F. Kang, M.L. Tsai, Y.L. Chueh, J.H. He, Resistive memory for harsh electronics: Immunity to surface effect and high corrosion resistance via surface modification, Sci. Rep. 4 (2014) 1–5.
21. [21] S.S. Shinde, P.S. Shinde, S.M. Pawar, A. V. Moholkar, C.H. Bhosale, K.Y. Rajpure, Physical properties of transparent and conducting sprayed fluorine doped zinc oxide thin films, Solid State Sci. 10 (2008) 1209–1214.
22. [22] B.D. Cullity, Elements of X-Ray Diffraction, Addison-Wesley Publishing Company, Inc., 1956.
23. [23] A. Tubtimtae, M.W. Lee, ZnO nanorods on undoped and indium-doped ZnO thin films as a TCO layer on nonconductive glass for dye-sensitized solar cells, Superlattices Microstruct. 52 (2012) 987–996.
24. [24] S.P. Bharath, K. V. Bangera, G.K. Shivakumar, Enhanced gas sensing properties of indium doped ZnO thin films, Superlattices Microstruct. 124 (2018) 72–78.
25. [25] P. Dhamodharan, J. Chen, C. Manoharan, Fabrication of In doped ZnO thin films by spray pyrolysis as photoanode in DSSCs, Surfaces and Interfaces. 23 (2021) 100965.
26. [26] T. V. Vimalkumar, N. Poornima, K.B. Jinesh, C.S. Kartha, K.P. Vijayakumar, On single doping and co-doping of spray pyrolysed ZnO films: Structural, electrical and optical characterisation, Appl. Surf. Sci. 257 (2011) 8334–8340.
27. [27] P. Nuthongkum, P. Yansakorn, K. Chongsri, R. Noonuruk, P. Junlabhut, Improvement of structural, optical and electrical properties of indium-doped ZnO nanoparticles synthesized by Co-precipitation method, J. Mater. Sci. Mater. Electron. 34 (2023) 1–10.
28. [28] A.T.T. Pham, N.M. Ngo, O.K.T. Le, D. Van Hoang, T.H. Nguyen, T.B. Phan, V.C. Tran, High-mobility sputtered F-doped ZnO films as good-performance transparent-electrode layers, J. Sci. Adv. Mater. Devices. 6 (2021) 446–452.
29. [29] G. Haacke, New figure of merit for transparent conductors *, J. Appl. Phys. 47 (1976) 4086–4089.