Electrical Characterization of ZnO (Al) / p-Si Heterojunctions Fabricated by SolGel Method

Abstract

In this work, the electrical properties of heterojunctions formed by coating of undoped Zinc Oxide (ZnO) and 2% Aluminum doped zinc oxid (AZO) on p-type silicon (p-Si) were investigated. ZnO and AZO nanoparticles were synthesized by Sol-Gel method and ZnO / p-Si, ZnO (Al) / p-Si heterojunctions were formed by spin coating technique. After the coating, the samples were thermally annealed at 450 oC for 30 minutes. Current-Voltage (I-V) and Capacitance-Voltage (C-V) measurements taken at 10K-300K show that the samples exhibit diode behavior with very low leakage current. Built-in potential (Vbi) and carrier concentrations (Nd) of diodes were calculated from C-V measurement results. Deep level transition spectroscopy (DLTS) technique was used to investigate trap levels around the depletion region. The presence of electron traps in both samples was determined.

Keywords

• ZnO thin film,Al doping,ZnO/p-Si heterojunction,DLTS

Sol-Jel Yöntemi ile Üretilen ZnO(Al)/p-Si Heteroekleminin Elektriksel Karakterizasyonu

Abstract

Bu çalışmada, p-tipi Silisyum (p-Si) üzerine katkısız Çinko Oksit (ZnO) ve %2 Alüminyum katkılı çinko oksit (ZnOAl) kaplanarak oluşturulan heteroeklemlerin elektriksel özellikleri incelenmiştir. ZnO ve ZnOAl nanoparçacıklar Sol-Jel yöntemi ile sentezlenmiş ve ZnO/p-Si, ZnOAl/p-Si heteroeklemleri döndürme kaplama tekniği ile oluşturulmuştur. Kaplama sonrası örneklere 450 ^oC’de 30 dk termal tavlama işlemi uygulanmıştır. 10K-300K aralığında alınan Akım-Voltaj (I-V) ve Kapasite-Voltaj (C-V) ölçümleri örneklerin çok düşük sızıntı akımına sahip diyot davranışı sergilediğini göstermektedir. C-V ölçüm sonuçlarından diyotların bariyer yüksekliği (V_bi) ve taşıyıcı konsantrasyonları (N_d) hesaplandı. Derin seviye geçiş spektroskopisi (DLTS) tekniği ile arınma bölgesi civarında bulunan tuzak seviyeleri araştırılmıştır. Her iki örnekte de elektron tuzaklarının varlığı tespit edilmiştir.

Keywords

• ZnO ince film,Al katkılama,ZnO/p-Si heteroeklemi,DLTS

References

1. N. Akçay, G. Algün, N. Ü. Kılıç, S. Shawuti, and M. M. Can, “Europium dependent absorption properties of Zn1−(y+0.01)(Al0.01,Euy)O (y = 0.00, 0.01, 0.03 and 0.05) thin films grown on the soda-lime glass substrates by spin coating,” J. Mater. Sci. Mater. Electron., vol. 28, no. 5, pp. 4492–4497, 2017.
2. N. Zebbar, Y. Kheireddine, K. Mokeddem, A. Hafdallah, M. Kechouane, and M. S. Aida, “Structural, optical and electrical properties of n-ZnO/p-Si heterojunction prepared by ultrasonic spray,” Mater. Sci. Semicond. Process., vol. 14, no. 3–4, pp. 229–234, 2011.
3. C. H. Chu, H. W. Wu, and J. L. Huang, “AZO/Au/AZO tri-layer thin films for the very low resistivity transparent electrode applications,” Mater. Sci. Eng. B Solid-State Mater. Adv. Technol., vol. 186, no. 1, pp. 117–121, 2014.
4. Y. Liu, Y. Li, and H. Zeng, “ZnO-based transparent conductive thin films: Doping, performance, and processing,” J. Nanomater., vol. 2013, no. Cvd, 2013.
5. L. Zhu and W. Zeng, “Room-temperature gas sensing of ZnO-based gas sensor: A review,” Sensors Actuators, A Phys., vol. 267, pp. 242–261, 2017.
6. R. Ghosh and D. Basak, “Electrical and ultraviolet photoresponse properties of quasialigned ZnO nanowires/ p-Si heterojunction,” Appl. Phys. Lett., vol. 90, no. 24, pp. 2005–2008, 2007.
7. X. Zong and R. Zhu, “Zinc oxide nanorod field effect transistor for long-time cellular force measurement,” Sci. Rep., vol. 7, no. October 2016, pp. 1–8, 2017.
8. G. Algün, “Humidity sensing properties of fluorine doped zinc oxide thin films,” J. Mater. Sci. Mater. Electron., vol. 29, no. 19, pp. 17039–17046, 2018.

9. N. Üzar, G. Algün, N. Akçay, D. Akcan, and L. Arda, “Structural, optical, electrical and humudity sensing properties of (Y/Al) co-doped ZnO thin films,” J. Mater. Sci. Mater. Electron., vol. 28, no. 16, 2017.
10. R. Pietruszka, B. S. Witkowski, E. Zielony, K. Gwozdz, E. Placzek-Popko, and M. Godlewski, “ZnO/Si heterojunction solar cell fabricated by atomic layer deposition and hydrothermal methods,” Sol. Energy, 2017.
11. D. C. Look, G. M. Renlund, R. H. Burgener, and J. R. Sizelove, “As-doped p-type ZnO produced by an evaporation/sputtering process,” Appl. Phys. Lett., vol. 85, no. 22, pp. 5269–5271, 2004.
12. G. Brauer, J. Kuriplach, C. C. Ling, and A. B. Djurišić, “Activities towards p-type doping of ZnO,” J. Phys. Conf. Ser., vol. 265, no. 1, 2011.
13. F. Yakuphanoglu, Y. Caglar, M. Caglar, and S. Ilican, “ZnO/p-Si heterojunction photodiode by solgel deposition of nanostructure n-ZnO film on p-Si substrate,” Mater. Sci. Semicond. Process., vol. 13, no. 3, pp. 137–140, 2010.
14. X. Wang et al., “ZnO thin film grown on silicon by metal-organic chemical vapor deposition,” J. Cryst. Growth, vol. 243, no. 1, pp. 13–18, 2002.
15. Y. S. Ocak, “Electrical characterization of DC sputtered ZnO/p-Si heterojunction,” J. Alloys Compd., vol. 513, pp. 130–134, 2012.
16. A. A. Ibrahim and A. Ashour, “ZnO/Si solar cell fabricated by spray pyrolysis technique,” J. Mater. Sci. Mater. Electron., 2006.
17. K. Gwozdz et al., “Deep traps in the ZnO nanorods/Si solar cells,” J. Alloys Compd., vol. 708, pp. 247–254, 2017.
18. T. Hanada, “Basic Properties of ZnO, GaN, and Related Materials,” in Oxide and Nitride Semiconductors, T. Yao and S.-K. Hong, Eds. Springer, Berlin, Heidelberg, 2009, pp. 1–19.
19. W. C. Dunlap and R. L. Watters, “Direct measurement of the dielectric constants of silicon and germanium,” Phys. Rev., vol. 92, no. 6, pp. 1396–1397, 1953.
20. D. V. Lang, “Deep-level transient spectroscopy: A new method to characterize traps in semiconductors,” J. Appl. Phys., vol. 45, no. 7, pp. 3023–3032, 1974.
21. M. U. Shahid, K. M. Deen, A. Ahmad, M. A. Akram, M. Aslam, and W. Akhtar, “Formation of Al-doped ZnO thin films on glass by sol–gel process and characterization,” Appl. Nanosci., vol. 6, no. 2, pp. 235–241, 2016.
22. C. E. Stutz, “Electrochemical Schottky characteristics of ZnO for capacitance-voltage measurements,” J. Electron. Mater., vol. 30, no. 12, pp. 2–4, 2001.
23. J.-C. Lin, M.-C. Huang, T. Wang, J.-N. Wu, Y.-T. Tseng, and K.-C. Peng, “Structure and characterization of the sputtered ZnO, Al-doped ZnO, Ti-doped ZnO and Ti, Al-co-doped ZnO thin films,” Mater. Express, vol. 5, no. 2, pp. 153–158, 2015.
24. A. Kaphle and P. Hari, “Characterization of Aluminum Doped Nanostructured ZnO/p-Si Heterojunctions,” Int. J. Eng. Sci., pp. 2319–1813, 2016.