Theoretical Investigation of Structural and Electronic Properties of Selenium Doped Zinc Oxide

Öz

Due to its electronic properties, Zinc Oxide (ZnO) is one of the important materials used in new generation solar cells. However, it is necessary to increase the working efficiency of pure ZnO with the rays coming from the sun. Doping with foreign atoms is one of the important techniques in this sense. In this study, the doping of ZnO crystal with Se atom was investigated theoretically. Density functional theory (DFT) was used in the calculations. However, DFT+U correction was made in the calculations to correct the known errors of the theory. With this method, the band gap of pure ZnO was calculated at 3.27 eV. This value is close to the experimental value of 3.44 eV. The Se atom causes local distortions in the crystal structure. However, these deteriorations do not significantly change the characteristic properties of the ZnO crystal. Doping with Se mainly leads to a change in the electronic structure. When the Se and Zn atoms, which have more valence electrons, are replaced, two occupied energy levels are formed in the band gap, above the valence band maximum, due to impurity. These energy levels increase the light absorption activity of ZnO in the visible region. Another important data obtained is that the lack of oxygen in the Se-doped ZnO crystal positively affects the absorption activity in the visible region

Anahtar Kelimeler

• Zinc oxide
• Selenium
• DFT+U
• Dopping
• Solar cells

Selenyum Katkılı Çinko Oksit'in Yapısal ve Elektronik Özelliklerinin Teorik İncelenmesi

Öz

Sahip olduğu elektronik özelliklerden dolayı Çinko Oksit (ZnO) yeni nesil güneş pillerinde kullanılan önemli malzemelerdendir. Ancak saf ZnO’nun güneşten gelen ışınlar ile çalışma veriminin arttırılması gerekmektedir. Yabancı atomlar ile katkılama bu anlamda önemli tekniklerden biridir. Bu çalışmada ZnO kristalinin Se atomu ile katkılanması teorik olarak incelenmiştir. Hesaplamalarda yoğunluk fonksiyoneli teorisi (YFT) kullanıldı. Ancak teorinin bilinen hatalarını düzeltmek için hesaplamalarda YFT+U düzeltmesi yapıldı. Bu metot ile saf ZnO’nun bant aralığı 3.27 eV değerinde hesaplandı. Bu değer deneysel değer olan 3.44 eV değerine yakındır. Se atomu kristal yapı içerisinde yerel bozulmalara yol açmaktadır. Ancak bu bozulmalar ZnO kristalinin karakteristik özelliklerini kayda değer değiştirmemektedir. Se ile katkılama esas olarak elektronik yapıda değişime yol açmaktadır. Daha fazla değerlik elektronuna sahip Se ile Zn atomu yer değiştirdiğinde bant aralığında, valans bant maksimumunun üzerinde safsızlıktan kaynaklanan iki dolu enerji seviyesi oluşmaktadır. Oluşan bu enerji seviyeleri ZnO’nun görünür bölgedeki ışığın absorpsiyonu aktivitesini artırmaktadır. Elde edilen diğer bir önemli veri ise Se katkılı ZnO kristalinde oksijen eksikliğinin olmasının görünür bölgedeki absorpsiyon aktivitesini olumlu yönde etkilemesidir.

Anahtar Kelimeler

• Selenyum
• Çinko Oksit
• YFT+U
• Katkılama
• Güneş hücreleri

Kaynakça

1. Bando, K., Sawabe, T., Asaka, K., and Masumoto, Y. (2004). Room-temperature excitonic lasing from ZnO single nanobelts. Journal of Luminescence, 108(1):385-388. Proceedings of the Fourteenth International Conference on Dynamical Processes in Excited States of Solids.
2. Cao, H., Lu, P., Cai, N., Zhang, X., Yu, Z., Gao, T., and Wang, S. (2014). First-principles study on electronic and magnetic properties of (Mn,Fe)-codoped ZnO. Journal of Magnetism and Magnetic Materials, 352:66-71.
3. Chen, Y., Wang, L., Wang, W., & Cao, M. (2017). Synthesis of Se-doped ZnO nanoplates with enhanced photoelectrochemical and photocatalytic properties. Materials Chemistry and Physics, 199, 416-423.
4. Cho, S., Jang, J.-W., Lee, J. S., and Lee, K.-H. (2012). Porous ZnO-ZnSe nanocomposites for visible light photocatalysis. Nanoscale, 4:2066-2071.
5. Clark, S. J., Segall, M. D., Pickard, C. J., Hasnip, P. J., Probert, M. J., Refson, K., and Payne, M. (2005). First principles methods using CASTEP. Z. Kristall., 220:567-570.
6. Dejam, L., Kulesza, S., Sabbaghzadeh, J., Ghaderi, A., Solaymani, S., Țălu, Ștefan, H. Sari, A. (2023). ZnO, Cu-doped ZnO, Al-doped ZnO and Cu-Al doped ZnO thin films: Advanced micro-morphology, crystalline structures and optical properties. Results in Physics, 44, 106209.
7. Dudarev, S. L., Botton, G. A., Savrasov, S. Y., Humphreys, C. J., and Sutton, A. P. (1998). Electron-energy-loss spectra and the structural stability of nickel oxide: An LSDA+U study. Phys. Rev. B, 57:1505-1509.
8. Göpel, W., Pollmann, J., Ivanov, I., and Reihl, B. (1982). Angle-resolved photoemission from polar and nonpolar zinc oxide surfaces. Phys. Rev. B, 26:3144-3150.

9. Greene, L. E., Law, M., Goldberger, J., Kim, F., Johnson, J. C., Zhang, Y., Saykally, R. J., and Yang, P. (2003). Low-temperature wafer-scale production of zno nanowire arrays. Angewandte Chemie International Edition, 42(26):3031-3034.
10. Hagendorfer, H., Lienau, K., Nishiwaki, S., Fella, C. M., Kranz, L., Uhl, A. R., Jaeger, D., Luo, L., Gretener, C., Buecheler, S., Romanyuk, Y. E., and Tiwari, A. N. (2014). Highly transparent and conductive ZnO: Al thin films from a low temperature aqueous solution approach. Advanced Materials, 26(4):632-636.
11. Hohenberg, P. and Kohn, W. (1964). Inhomogeneous electron gas. Phys. Rev., 136:B864-B871.
12. Illy, B., Shollock, B. A., MacManus-Driscoll, J. L., and Ryan, M. P. (2005). Electrochemical growth of zno nanoplates. Nanotechnology, 16(2):320.
13. Kara, R., Mentar, L., and Azizi, A. (2020). Synthesis and characterization of Mg-doped ZnO thin-films electrochemically grown on fto substrates for optoelectronic applications. RSC Adv., 10:40467-40479.
14. Kohn, W. and Sham, L. J. (1965). Self-consistent equations including exchange and correlation effects. Phys. Rev., 140:A1133-A1138.
15. Lany, S. and Zunger, A. (2010). Many-body GW calculation of the oxygen vacancy in ZnO. Phys. Rev. B, 81:113201.
16. Liu, L., Mei, Z., Tang, A., Azarov, A., Kuznetsov, A., Xue, Q.-K., and Du, X. (2016). Oxygen vacancies: The origin of n-type conductivity in zno. Phys. Rev. B, 93:235305.
17. Ma, H., Williams, P. L., and Diamond, S. A. (2013a). Ecotoxicity of manufactured ZnO nanoparticles - a review. Environmental Pollution, 172:76–85.
18. Ma, X., Wu, Y., Lv, Y., and Zhu, Y. (2013b). Correlation effects on lattice relaxation and electronic structure of zno within the GGA+U formalism. The Journal of Physical Chemistry C, 117(49):26029-26039.
19. Monkhorst, H. J. and Pack, J. D. (1976). Special points for Brillouin-zone integrations. Phys. Rev. B, 13:5188-5192.
20. Nouri, H. and Habibi-Yangjeh, A. (2014). Microwave-assisted method for preparation of Zn1-xMgxO nanostructures and their activities for photodegradation of methylene blue. Advanced Powder Technology, 25(3):1016-1025.
21. Omidi, A., Habibi-Yangjeh, A., and Pirhashemi, M. (2013). Application of ultrasonic irradiation method for preparation of ZnO nanostructures doped with Sb+3 ions as a highly efficient photocatalyst. Applied Surface Science, 276:468-475.
22. Perdew, J. P., Burke, K., and Ernzerhof, M. (1996). Generalized gradient approximation made simple. Phys. Rev. Lett., 77:3865-3868.
23. Rezaei, M. and Habibi-Yangjeh, A. (2013a). Microwave-assisted preparation of Ce-doped ZnO nanostructures as an efficient photocatalyst. Materials Letters, 110:53-56.
24. Rezaei, M. and Habibi-Yangjeh, A. (2013b). Simple and large scale refluxing method for preparation of ce-doped ZnO nanostructures as highly efficient photocatalyst. Applied Surface Science, 265:591-596.
25. Sanakousar, F. M., Vidyasagar, C. C., Jiménez-Pérez, V. M., & Prakash, K. (2022). Recent progress on visible-light-driven metal and non-metal doped ZnO nanostructures for photocatalytic degradation of organic pollutants. Materials Science in Semiconductor Processing, 140, 106390.
26. Snigurenko, D., Jakiela, R., Guziewicz, E., Przezdziecka, E., Stachowicz, M., Kopalko, K., Barcz, A., Lisowski, W., Sobczak, J., Krawczyk, M., and Jablonski, A. (2014). Xps study of arsenic doped zno grown by atomic layer deposition. Journal of Alloys and Compounds, 582:594-597.
27. Sun, Y., Fuge, G., Fox, N., Riley, D., and Ashfold, M. (2005). Synthesis of aligned arrays of ultrathin ZnO nanotubes on a si wafer coated with a thin ZnO film. Advanced Materials, 17(20):2477-2481.
28. Taha, K. K., Mustafa, M. M., Ahmed, H. A. M., and Talab, S. (2019). Selenium zinc oxide (Se/ZnO) nanoparticles: Synthesis, characterization, and photocatalytic activity. Zeitschrift für Naturforschung A, 74(12):1043-1056.
29. Tien, L. C., Sadik, P. W., Norton, D. P., Voss, L. F., Pearton, S. J., Wang, H. T., Kang, B. S., Ren, F., Jun, J., and Lin, J. (2005). Hydrogen sensing at room temperature with Pt-coated ZnO thin films and nanorods. Applied Physics Letters, 87(22):222106.
30. Xie, W., Li, R., and Xu, Q. (2018). Enhanced photocatalytic activity of Se-doped TiO2 under visible light irradiation. Scientific Reports, 8(1):8752.
31. Zeng, Y., Ye, Z., Xu, W., Liu, B., Che, Y., Zhu, L., and Zhao, B. (2007). Study on the Hall-effect and photoluminescence of N-doped p-type ZnO thin films, 61(1):41-44.