Influence of ZnO seed layer precursor molar ratio on the density of interface defects in low temperature aqueous chemically synthesized ZnO nanorods/GaN light-emitting diodes

Journal Article · Thu Apr 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4947593· OSTI ID:22594665

Alnoor, Hatim; Iandolo, Donata; Willander, Magnus; Nur, Omer ^[1]; Pozina, Galia; Khranovskyy, Volodymyr; Liu, Xianjie ^[2]

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1. Department of Science and Technology (ITN), Linköping University, SE-601 74 Norrköping (Sweden)
2. Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-583 81 Linköping (Sweden)

Low temperature aqueous chemical synthesis (LT-ACS) of zinc oxide (ZnO) nanorods (NRs) has been attracting considerable research interest due to its great potential in the development of light-emitting diodes (LEDs). The influence of the molar ratio of the zinc acetate (ZnAc): KOH as a ZnO seed layer precursor on the density of interface defects and hence the presence of non-radiative recombination centers in LT-ACS of ZnO NRs/GaN LEDs has been systematically investigated. The material quality of the as-prepared seed layer as quantitatively deduced by the X-ray photoelectron spectroscopy is found to be influenced by the molar ratio. It is revealed by spatially resolved cathodoluminescence that the seed layer molar ratio plays a significant role in the formation and the density of defects at the n-ZnO NRs/p-GaN heterostructure interface. Consequently, LED devices processed using ZnO NRs synthesized with molar ratio of 1:5 M exhibit stronger yellow emission (∼575 nm) compared to those based on 1:1 and 1:3 M ratios as measured by the electroluminescence. Furthermore, seed layer molar ratio shows a quantitative dependence of the non-radiative defect densities as deduced from light-output current characteristics analysis. These results have implications on the development of high-efficiency ZnO-based LEDs and may also be helpful in understanding the effects of the ZnO seed layer on defect-related non-radiative recombination.

• OSTI ID: 22594665
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 16; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CATHODOLUMINESCENCE
COMPARATIVE EVALUATIONS
DEFECTS
DENSITY
ELECTROLUMINESCENCE
GALLIUM NITRIDES
INTERFACES
LAYERS
LIGHT EMITTING DIODES
NANOSTRUCTURES
POTASSIUM HYDROXIDES
PRECURSOR
TEMPERATURE RANGE 0065-0273 K
X-RAY PHOTOELECTRON SPECTROSCOPY
ZINC OXIDES