Preparation and characterization of nitrogen doped ZnO films and homojunction diodes

Authors

  • A. E. RAKHSHANI Department of Physics, Faculty of Science, Kuwait University, P. O. Box 5969, Safat 13060, Kuwait
  • A. BUMAJDAD Department of Chemistry, Faculty of Science, Kuwait University, P. O. Box 5969, Safat 13060, Kuwait.
  • J. KOKAJ Department of Physics, Faculty of Science, Kuwait University, P. O. Box 5969, Safat 13060, Kuwait
  • S. THOMAS Department of Physics, Faculty of Science, Kuwait University, P. O. Box 5969, Safat 13060, Kuwait

Keywords:

Composition, homojunction, optoelectronic, XPS, ZnO, N

Abstract

Nitrogen-doped ZnO (ZnO:N) films were prepared by the reactive magnetron sputtering technique using a zinc target. The effect of thermal annealing in different ambient on the films composition, chemical bonding states, structure, optical transmittance and photoconductivity was investigated. The as-grown films are composed from 9-nm large grains with strained unit cell. The annealing process relaxes the strain and increases the grain size to 39 nm. Annealing also increases the direct band gap of the film from 2.42 eV to 3.26 eV. The as-grown and annealed films show photoconductivity in the visible region which is partly due to the effect of a nitrogen-related defect level with the ionization energy of 1.71 eV. The conversion of the as-grown n-type films to p-type ZnO was achieved by annealing the films in air. The converted p-ZnO and electrodeposited n-ZnO films were used in the fabrication of light-emitting homojunction diodes. Diodes with a reasonably good current-voltage rectification factor exhibited electroluminescence property in the ultraviolet-visible region. From the junction capacitance of these diodes the density of holes in p-ZnO films grown on stainless steel substrates was determined as 1.5x1017 cm-3.

References

Auret, F. D., Goodman, S. A., Legodi, M. J., Meyer, W. E. Look, D. C. 2002. Electrical characterization of vapor-phase-grown single-crystal ZnO. Applied Physics Letters 80: 1340.

Djurisic, A. B., Leung, Y. H., Tam, K. H., Hsu, Y. F., Ding, L., Ge, W. K., Zhong, Y. C., Wong, K. S., Chan, W. K., Tam, H. L., Cheah, K. W., Kwok, W. M. Phillips, D. L. 2007. Defect emissions in ZnO nanostructures. Nanotechnology 18: 095702.

Fons, P., Tampo, H., Kolobov, A. V., Ohkubo, M., Niki, S., Tominaga, J., Carboni, R., Boscherini, F. Friedrich, S. 2006. Direct observation of nitrogen location in molecular beam epitaxy grown nitrogen-doped ZnO. Physical Review Letters 96: 045504.

Kato H., Yamamuro T., Ogawa A., Kyotani C. Sano M. 2011. Impact of Mixture Gas Plasma of N2 and O2 as the N source on ZnO-based ultraviolet light-emitting diodes fabricated by molecular beam epitaxy. Applied Physics Express 4: 091105.

Khan, W. S. Cao, C. 2010. Synthesis, growth mechanism and optical characterization of zinc nitride hollow structures. Journal of Crystal Growth 312: 1838-1843.

Kokaj, J. Rakhshani, A. E. 2004. Photocurrent spectroscopy of solution-grown CdS films annealed in CdCl2 vapour. Journal of Physics D: Applied Physics 37: 1970-1975.

Konenkamp, R., Word, R. C., Dosmailov, M., Meiss, J. Nadarajah, A. 2007. Selective growth of single-crystalline ZnO nanowires on doped silicon. Journal of Applied Physics 102: 056103.

Li, B. S., Liu, Y. C., Zhi, Z. Z., Shen, D. Z., Lu, Y. M., Zhang, J. Y., Fan, X. W., Mu, R. X. Henderson, Don. O. 2003. Optical properties and electrical characterization of p-type ZnO thin films prepared by thermally oxidizing Zn3N2thin films. Journal of Materials Research 18: 8-13.

Li, L., Shan, C. X., Li, B. H., Yao, B., Zhang, J. Y., Zhao, D. X., Zhang, Z. Z., Shen, D. Z., Fan, X. W., Lu, Y. M. 2008. The compensation source in nitrogen doped ZnO. Journal of Physics D: Applied Physics 41:245402.

Liu J. S., Shan C. X., Shen H., Li B. H., Zhang Z. Z., Liu L., Zhang L. G. Shen D. Z. 2012. ZnO light-emitting devices with a lifetime of 6.8 hours. Applied Physics Letters 101: 011106.

Liu, W. W., Yao, B., Zhang, Z. Z., Li, Y. F., Li, B. H., Shan, C. X., Zhang, J. Y., Shen, D. Z. Fan, X. W. 2011. Doping efficiency, optical and electrical properties of nitrogen-doped ZnO films. Journal of Applied Physics 109: 093518.

Look, D. C. 2005. Electrical and optical properties of p-type ZnO. Semiconductor Science and Technology 20: S55-S61.

Lyons J. L., Janotti A. Van de Walle C. G. 2009. Why nitrogen cannot lead to p-type conductivity in ZnO. Applied Physics Letters 95: 252105.

Nakahara K., Akasaka S., Yuji H., Tamura K., Fujii T., Nishimoto Y., Takamizu D., Sasaki A., Tanabe T., Takasu H., Amaike H., Onuma T., Chichibu S. F., Tsukazaki A., Ohtomo A. Kawasaki M. 2010. Nitrogen doped MgxZn1-xO/ZnO single heterostructure ultraviolet light-emitting diodes on ZnO substrates. Applied Physics Letters 97: 013501.

Nakano, Y., Morikawa, T., Ohwaki, T. Taga, Y. 2005. Deep level characterization of N-doped ZnO films prepared by reactive magnetron sputtering. Applied Physics Letters 87: 232104.

Nakano, Y., Morikawa, T., Ohwaki, T. Taga, Y. 2006. Electrical characterization of p-type N-doped ZnO films prepared by thermal oxidation of sputtered Zn3N2 films. Applied Physics Letters 88: 172103.

Neamen, D. A. 2003. Semiconductor Physics and Devices: Basic Principles. McGraw Hill, New York. Pp 252.

Nunez, C. G., Pau, J. L., Hernandez, M. J., Cervera, M., Ruiz, E. Piqueras, J. 2012. On the zinc nitride properties and the unintentional incorporation of oxygen. Thin Solid Films 520: 1924-1929.

Ozgur U., Alivov, Ya. I., Liu, C., Teke, A., Reshchikov, M. A., Dog an, S., Avrutin, V., Cho, S. -J. Morko٥d, H. 2005. A comprehensive review of ZnO materials and devices. Journal of Applied Physics 98: 041301.

Paniconi, G., Stoeva, Z., Smith, R. I., Dippo, C. P., Gallagherd, B. L. Gregory, D. H. 2008. Synthesis, stoichiometry and thermal stability of Zn3N2 powders prepared by ammonolysis reactions. Journal of Solid State Chemistry 181: 158-165.

Pearton, S. J., Norton, K. I., Heo, Y. W. Steiner, T. 2003. Recent progress in processing and properties of ZnO. Superlattices and Microstructures 34: 3-32.

Perkins, C., Lee, S. H., Lee, X., Asher, S. E. Coutts, T. J. 2005. Identification of nitrogen chemical states in N-doped ZnO via x-ray photoelectron spectroscopy. Journal of Applied Physics 97: 034907.

Qureshi, A., Shah, S., Pelagade, S., Singh, N. L., Mukherjee, S., Tripathi, A., Despande, U. P. Shripathi, T. 2010. Surface modification of polycarbonate by plasma treatment. Journal of Physics: Conference Series 208: 012108.

Rakhshani, A. E. 2002. Optoelectrical properties of electrodeposited CdxHg1-xTe with a bandgap energy of 1.35 eV. Semiconductor Science and Technology 17: 924-930.

Rakhshani, A. E. 2008. Optical and electrical characterization of well-aligned ZnO rods electrodeposited on stainless steel foil. Applied Physics A 92: 303-308.

Rakhshani, A. E. 2010. Optoelectronic properties of p-n and p-i-n heterojunction devices prepared by electrodeposition of n-ZnO on p-Si. Journal of Applied Physics 108: 094502.

Sun F., Shan C. X., Li B. H., Zhang Z. Z., Shen D. Z., Zhang Z. Y. Fan D. 2011. A reproducible route to p-ZnO films and their application in light-emitting devices. Optics Letters 36: 499-501.

Tarun M. C., Zafar Iqbal M. McCluskey M. D. 2011. Nitrogen is a deep acceptor in ZnO. AIP Advances 1: 022105.

Wang, C., Ji, Z., Liu, K., Xiang, Y., Ye, Z. 2003. p-Type ZnO thin films prepared by oxidation of Zn3N2 thin films deposited by DC magnetron sputtering. Journal of Crystal Growth 259: 279-281.

Wang, D., Liu, Y. C., Mu, R., Zhang, J. Y., Lu, Y. M., Shen, D. Z. Fan, X. W. 2004. The photoluminescence properties of ZnO:N films fabricated by thermally oxidizing Zn3N2 films using plasma-assisted metal-organic chemical vapour deposition. Journal of Physics: Condensed Matter 16: 4635-4642.

Watanabe, F., Shirai, H., Fujii, Y. Hanajiri, T. 2011. Rapid thermal annealing of sputter-deposited ZnO/ZnO:N/ZnO multilayered structures. Thin solid Films 520: 3729-3735.

Yang, T., Zhang, Z., Li, Y., Lv, M., Song, S., Wub, Z., Yan, J. Han, S. 2009. Structural and optical properties of zinc nitride films prepared by rf magnetron sputtering. Applied Surface Science 255: 3544-3547.

Zhang, J. P., Zhang, L. D., Zhu, L. Q., Zhang, Y., Liu, M. Wang, X. J. 2007. Characterization of ZnO:N films prepared by annealing sputtered zinc oxynitride films at different temperatures. Journal of Applied Physics 102:114903.

Zong, F., Ma, H., Xue, C., Du, W., Zhang, X., Xiao, H., Ma, J. Ji, F. 2006. Structural properties of zinc nitride empty balls. Materials Letters 60: 905-908.

Zou, C. W., Chen, R. Q. Gao, W. 2009. The microstructures and the electrical and optical properties of ZnO:N films prepared by thermal oxidation of Zn3N2 precursor. Solid State Communications 149: 2085-2089.

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Published

07-01-2014