Abstract
Growth of nanostructured ZnO by solution process always lead to the formation of various kinds of defects. Defect states also can aid in improving different properties of the material. In the case of light-emitting diodes (LEDs), major research is focused on tuning the emission colour so as to achieve white emission without the use of any phosphors. Vertically aligned ZnO nanorods were grown over Mg:GaN substrate by hydrothermal process. High-resolution X-ray diffraction (HRXRD) analysis confirms the epitaxial growth of nanorods over the substrate. The photoluminescence (PL) studies revealed a narrow near band edge emission and a broad defect-induced deep level emission. The intensity of deep level emissions related to Zni, Vo, O i defects decreases on annealing. The V–I characteristics of the heterojunction showed excellent rectifying nature with electroluminescence emission on forward bias. Device fabricated by as-grown ZnO nanorods emits in the UV–blue region and broad emission in the visible region. While the annealed device emitted only in UV–blue region. The emission wavelengths closely matched with that of defect state emissions obtained in the PL studies. By annealing, various defect states density can be controlled, thereby emission colour tuned from white to blue.
Similar content being viewed by others
References
Nakamura S, Yasuhiro H and Masayuki S 1991 Appl. Phys. Lett. 58 2021
Akasaki I 1997 MRS Proc. 482 3
Verma J, Prem K K, Vladimir P, Amit V, Huili G X and Debdeep J 2013 Appl. Phys. Lett. 102 041103
Mao Z, Ying-Chun Z, Yang W and Lin G 2014 J. Mater. Sci. 49 4439
Viana B, Pauporte T, Lupan O, Devis L and Gacoin T 2014 Proc. SPIE 8987 89871T
Wang J, Xiping J, Chunhua Y and Jianhua L 2005 J. Electrochem. Soc. 152 G186
Kim D C, Won S H, Bo H K, Hyung K C and Chang H H 2007 Physica B: Condens. Matter 401 386
Schuster F, Bernhard L, Reza R Z, Cesar M, Joan R M, Jordi A and Martin S 2014 ACS Nano 8 4376
Abbasi M A, Zafar H I, Mushtaque H, Omer N and Magnus W 2013 Nanoscale Res. Lett. 8 320
Ng A M C, Xi Y Y, Hsu Y F, Djurisić A B, Chan W K, Gwo S, Tam H L, Cheah K W, Fong P W K, Lui H F and Surya C 2009 Nanotechnology 20 445201
Jha S, Wang C D, Luan C Y, Liu C P, Bin H, Kutsay O, Bello I, Zapien J A, Zhang W J and Lee S T 2012 J. Electron. Mater. 41 853
Yin Z, Xiaoyan L, Hanchao Y, Yongzhong W, Xiaopeng H, Min H and Xiangang X 2013 IEEE Photonic Technol. Lett. 25 1989
Yin Z, Xiaoyan L, Yongzhong W, Xiaopeng H and Xiangang X 2012 Opt. Express 20 1013
Wu J H, Shu Y L, Shuti L, Yu L J, Guo P R and Xin P Q 2012 Appl. Phys. A 109 489
Zhu H, Javed I, Hongjun X and Dapeng Y 2008 J. Chem. Phys. 129 124713
Gomi M, Naoko O, Kenichi O and Mikio K 2003 Jpn. J. Appl. Phys. 42 481
Davydov V, Yu K, Goncharuk I, Smirnov A, Graul J, Semchinova O, Uffmann D, Smirnov M, Mirgorodsky A and Evarestov R 1998 Phys. Rev. B 58 12899
Kaufmann U, Kunzer M, Maier M, Obloh H, Ramakrishnan A, Santic B and Schlotter P 1998 Appl. Phys. Lett. 72 1326
Monemar B, Paskov P P, Pozina G, Hemmingsson C, Bergman J P, Khromov S, Izyumskaya V N, Avrutin V, Li X, Morkoc H, Amano H, Iwaya M and Akasaki I 2014 J. Appl. Phys. 115 053507
Monemar B, Sergey K, Galia P, Plamen P, Peder B, Carl H, Lars H, Hiroshi A, VItaliy A, Xing L and Madis M 2013 Jpn. J. Appl. Phys. 52 08JJ03
Song J O and Tae Y S 2004 Appl. Phys. Lett. 85 6374
Song J O, Hyun G H, Joon W J, Jung I S, Ja S J and Tae Y S 2008 Electrochem. Solid-State Lett. 11 H36
Song J O, Jun S H and Tae Y S 2010 IEEE Trans. Electron. Devices 57 42
Song J O, Dong S L, Park Y, Chae S W and Tae Y S 2005 IEEE Photonics Technol. Lett. 17 291
Rodnyi P A and Khodyuk I V 2011 Opt. Spectrosc. 111 776
Ahn C H, Young Y K, Dong C K, Sanjay K M and Hyung K C 2009 J. Appl. Phys. 105 013502
Myoung J M, Shim K H, Kim C, Gluschenkov O, Kim K, Kim S, Turnbull D A and Bishop S G 1996 Appl. Phys. Lett. 69 2722
Jeong M C, Byeong Y O, Moon H H, Sang W L and Jae M M 2007 Small 3 568
Acknowledgements
We also acknowledge DST Nanomission for the financial support. L S Vikas acknowledges UGC for fellowship under UGC-RFSMS scheme.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
VIKAS, L.S., SRUTHI, C.K. & JAYARAJ, M.K. Defect-assisted tuning of electroluminescence from p-GaN/n-ZnO nanorod heterojunction. Bull Mater Sci 38, 901–907 (2015). https://doi.org/10.1007/s12034-015-0920-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12034-015-0920-1