Study of the structural and optical properties of ZnO films deposited by magnetron sputtering at room temperature

Saenko A.V., Bilyk G.E., Zheits V.V., Khubezhov S.A., Vakulov Z.E., Smirnov V.A.

For Russian citation (Opticheskii Zhurnal):

Саенко А.В., Билык Г.Е., Жейц В.В., Хубежов С.А., Вакулов З.Е., Смирнов В.А. Исследование структурных и оптических свойств пленок ZnO, полученных методом магнетронного распыления при комнатной температуре // Оптический журнал. 2025. Т. 92. № 1. С. 90–99. http://doi.org/10.17586/1023-5086-2025-92-01-90-99

Saenko A.V., Bilyk G.E., Zheits V.V., Khubezhov S.A., Vakulov Z.E., Smirnov V.A. Study of the structural and optical properties of ZnO films deposited by magnetron sputtering at room temperature [in Russian] // Opticheskii Zhurnal. 2025. V. 92. № 1. P. 90–99. http://doi.org/10.17586/1023-5086-2025-92-01-90-99

For citation (Journal of Optical Technology):

Abstract:

Subject of study. Nanocrystalline ZnO films on glass and flexible substrates for applications in solar energy, transparent and flexible electronics. Aim of study. Determination of the radio-frequency magnetron sputtering optimal power for obtaining a homogeneous crystalline structure with low surface roughness during the deposition of ZnO films. Method. The deposition of ZnO films was carried out by high-frequency magnetron sputtering of a ceramic target in an oxygen-free environment at room temperature. The ZnO films were studied using scanning electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and spectrophotometry. Main results. It has been shown that the dependence of the deposition rate of ZnO films on the power of high-frequency magnetron sputtering in an oxygen-free environment at room temperature is linear. It has been shown that the deposition rate of ZnO films from high-frequency magnetron sputtering power in an oxygen-free environment at room temperature is linear. The resulting ZnO films have a nanocrystalline structure with a dominant diffraction peak (002) for the hexagonal ZnO structure and a predominant crystallite growth direction perpendicular to the substrate surface. It is shown that an increase in sputtering power from 25 to 100 W leads to an increase in grain size from 12.8 to 35.7 nm and surface roughness of ZnO films from 2.8 to 11.4 nm. It was found that ZnO films have a transmittance in the visible region of the spectrum about 90% and an optical band gap of 3.27–3.28 eV. X-ray photoelectron spectroscopy studies confirmed the chemical composition of ZnO films. Practical significance. It has been established that the optimal power of magnetron sputtering in an oxygen-free environment at room temperature is 75 W, at which ZnO films have a relatively smooth surface and a uniform nanocrystalline structure, which is promising for the effective separation of photogenerated electron-hole pairs and the transfer of charge carriers to electrodes in solar cell structures, including on a flexible substrate.

Keywords:

ZnO films, magnetron sputtering, room temperature, sputtering power, grain size, surface roughness, crystal structure, optical transmission

OCIS codes: 310.0310, 160.0160, 180.0180

References:

1. Subhash Chander, Surya Kant Tripathi. Recent advancement in efficient metal oxide-based flexible perovskite solar cells: A short review // Materials Adv. 2022. V. 3. P. 7198–7211. https://doi.org/10.1039/ D2MA00700B
2. Wisz G., Sawicka-Chudy P., Wal A., et al. TiO2:ZnO/CuO thin film solar cells prepared via reactive direct-current (DC) magnetron sputtering // Appl. Materials Today. 2022. V. 29. P. 101673. https://doi.org/10.1016/j. apmt.2022.101673
3. Достанко А.П., Агеев О.А., Голосов Д.А. и др. Электрические и оптические свойства пленок оксида цинка, нанесенных методом ионно-лучевого распыления оксидной мишени // Физика и техника полупроводников. 2014. Т. 48. № 9. C. 1274–1279.
Dostanko A.P., Ageev O.A., Golosov D.A., et al. Electrical and optical properties of zinc-oxide films deposited by the ion-beam sputtering of an oxide target // Semiconductors. 2014. V. 48. P. 1242–1247. https://doi. org/10.1134/S1063782614090073
4. Саенко А.В., Билык Г.Е., Малюков С.П. Моделирование оксидного солнечного элемента на основе гетероперехода ZnO/Cu2O // Прикладная физика. 2023. № 4. C. 66–77. https://doi.org/10.51368/1996-0948-2023-4-66-77
Saenko A.V., Bilyk G.E., Malyukov S.P. Modeling of an oxide solar cell based on a ZnO/Cu2O heterojunction // Appl. Phys. 2023. № 4. P. 66–77. https://doi. org/ 10.51368/1996-0948-2023-4-66-77
5. Kaim Paulina, Lukaszkowicz Krzysztof, Szindler Marek, et al. The influence of magnetron sputtering process temperature on ZnO thin-film properties // Coatings. 2021. V. 11. P. 1507. https://doi.org/10.3390/ coatings11121507
6. Kavindra Kandpal, Jitendra Singh, Navneet Gupta, et al. Effect of thickness on the properties of ZnO thin films prepared by reactive RF sputtering // J. Materials Sci.: Materials in Electronics. 2018. V. 29. P. 14501–14507. https://doi.org/10.1007/s10854-018-9584-0
7. Абдуев А.Х., Ахмедов А.К., Асваров А.Ш. и др. Прозрачные проводящие слои на основе ZnO, полученные магнетронным распылением композитной металлокерамической мишени ZnO:Ga-Zn: часть 2 // Поверхность. Рентгеновские, синхротронные и нейтронные исследования. 2021. № 2. С. 27–33. https:// doi.org/10.31857/ S1028096021010039
Abduev A.K., Akhmedov A.K., Asvarov A.S., et al. ZnO-based transparent conductive layers obtained by the magnetron sputtering of a composite cermet ZnO:Ga-Zn target: Part 2 // J. Surface Investigation. X-Ray, Synchrotron and Neutron Techniques. 2021. V. 15. P. 121–127. https://doi.org/10.1134/ S1027451021010031
8. Shinho Cho. Effects of growth temperature on the properties of ZnO thin films grown by radio-frequency magnetron sputtering // Trans. on Electrical and Electronic Materials. 2009. V. 10. № 6. P. 185–188. https:// doi.org/10.4313/TEEM.2009.10.6.185
9. Tominov R.V., Vakulov Z.E., Avilov V.I., et al. Synthesis and memristor effect of a forming-free ZnO nanocrystalline films // Nanomaterials. 2020. V. 10. P. 1007. https://doi.org/10.3390/nano10051007
10. Najeeb Al-Khalli, Mohamed F. Aly Aboud, Abdulaziz A. Bagabas, et al. Structural, optical, and electrical characteristics of thermal treated ZnO thin films deposited by RF sputtering on glass substrates // Materials Trans. 2021. V. 62. № 7. P. 915–920. https://doi.org/10.2320/matertrans.MT-M2020350
11. Spasova S., Dikov Hr., Ganchev M. Preparation and characterization of RF sputtered ZnO layers for application in thin films solar cells // J. Phys.: Conf. Ser. 2023. V. 2436. P. 012017. https://doi.org/10.1088/ 1742-6596/2436/1/012017
12. Саенко А.В., Вакулов З.Е., Климин В.С. и др. Влияние мощности магнетронного распыления на осаждение пленок ITO при комнатной температуре // Микроэлектроника. 2023. Т. 52. № 4. С. 329–335. https://doi.org/10.31857/S0544126923700394
Saenko A.V., Vakulov Z.E., Klimin V.S., et al. Effect of magnetron sputtering power on ITO film deposition at room temperature // Russian Microelectronics. 2023. V. 52. № 4. P. 297–302. https://doi.org/10.1134/S1063739723700452
13. Агекян В.Ф., Борисов Е.В., Гудовских А.С. и др. Формирование кристаллических слоев Cu2O и ZnO методом магнетронного распыления и их оптическая характеризация // Физика и техника полупроводников. 2018. Т. 52. № 3. P. 402–408. https://doi.org/10.21883/FTP.2018.03.45629.8682
Agekyan V.F., Borisov E.V., Gudovskikh A.S., et al. Formation of Cu2O and ZnO crystal layers by magnetron assisted sputtering and their optical characterization // Semiconductors. 2018. V. 52. P. 383–389. https://doi.org/10.1134/S1063782618030028
14. Mohammed Rasheed, Regis Barille. Room temperature deposition of ZnO and Al:ZnO ultrathin films on glass and PET substrates by DC sputtering technique // Optical and Quantum Electronics. 2017. V. 49. P. 190. https://doi.org/10.1007/ s11082-017-1030-7
15. Li Gong, Yun-Zhen Liu, Fang-Yang Liu, et al. Roomtemperature deposition of flexible transparent conductive Ga-doped ZnO thin films by magnetron sputtering on polymer substrates // J. Materials Sci.: Materials in Electronics. 2017. V. 28. P. 6093–6098. https://doi.org/10.1007/ s10854-016-6286-3
16. Hajara P., Priya Rose T., Saji K.J. Effect of substrate temperature and RF power on the structural and optical properties of sputtered ZnO thin films // J. Phys.: Conf. Ser. 2022. V. 2357. P. 012018. https://doi.org/ 10.1088/1742-6596/2357/1/012018
17. Шомахов З.В., Налимова С.С., Бобков А.А. и др. Рентгеновская фотоэлектронная спектроскопия