RAPID THERMAL ANNEALING INDUCED ENHANCED BAND-EDGE EMISSION FROM ZnO NANOWIRES, NANORODS AND NANORIBBONS

2011 ◽  
Vol 04 (01) ◽  
pp. 25-29 ◽  
Author(s):  
SOUMEN DHARA ◽  
P. K. GIRI
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Green Emission ◽  
Spectral Shift ◽  
Zno Nanowires ◽  
Band Edge ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Zno Nanostructures ◽  
Time Resolved

In this letter, we report on the enhanced near band edge (NBE) photoluminescence (PL) emission by rapid thermal annealing (RTA) of ZnO nanowires, nanoribbons and nanorods synthesized by vapor transport method using a ZnO nanopowder source. As a result of RTA, the intensity ratio of NBE to green emission peak is nearly doubled for the nanowires, while this enhancement is one order of magnitude for the nanoribbons and nanorods. Time-resolved PL studies on the green emission band shows a single-exponential decay (time constant ~ns) after RTA. The Raman spectral shift of the RTA treated samples indicates reduced tensile strain in the annealed ZnO nanostructures. Our results demonstrate the effectiveness of RTA process for improving the crystallinity and optical properties of ZnO nanostructures.

Stable enhancement of near-band-edge emission of ZnO nanowires by hydrogen incorporation

2010 ◽  
Vol 21 (6) ◽  
pp. 065709 ◽  
Author(s):  
A Dev ◽  
R Niepelt ◽  
J P Richters ◽  
C Ronning ◽  
T Voss
Keyword(s):  
Zno Nanowires ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Hydrogen Incorporation

scholarly journals Electrical properties and near band edge emission of Bi-doped ZnO nanowires

2007 ◽  
Vol 90 (8) ◽  
pp. 083113 ◽  
Author(s):  
Congkang Xu ◽  
Junghwan Chun ◽  
Dong Eon Kim ◽  
Ju-Jin Kim ◽  
Bonghwan Chon ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Zno Nanowires ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Doped Zno

Effect of Thermal Annealing on Deep and Near-band Edge Emission from ZnO Films Grown by Plasma-assisted MBE

2008 ◽  
Author(s):  
Vitaliy Avrutin ◽  
Michael A. Reshchikov ◽  
Natalia Izyumskaya ◽  
Ryoko Shimada ◽  
Steve W. Novak ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Zno Films ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission

Effect of hydrogen plasma treatment on the luminescence and photoconductive properties of ZnO nanowires

2009 ◽  
Vol 1206 ◽  
Author(s):  
Yanbo Li ◽  
Ryohei Uchino ◽  
Takero Tokizono ◽  
Alexander Paulsen ◽  
Miao Zhong ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Oxygen Vacancies ◽  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Green Emission ◽  
Zno Nanowires ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Hydrogen Atoms ◽  
Edge Emission

AbstractZnO nanowires with strong green emission synthesized by chemical vapor deposition were treated using hydrogen plasma. The effect of hydrogen plasma treatment was studied by means of photoluminescence and photoconductivity. A strong passivation of the green emission and a significant enhancement of the near band edge emission were found after the hydrogen plasma treatment. The conductivity of the nanowires in dark was increased by more than 3 orders of magnitude. The photoconductivity also increased after the hydrogen plasma treatment. The observed changes in the luminescence and photoconductive properties of the ZnO nanowires were likely caused by hydrogen atoms occupying both oxygen vacancies and interstitial sites.

Enhanced near-band-edge emission and field emission properties from plasma treated ZnO nanowires

2010 ◽  
Vol 100 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Qing Zhao ◽  
Tuocheng Cai ◽  
Sheng Wang ◽  
Rui Zhu ◽  
Zhimin Liao ◽  
...  
Keyword(s):  
Field Emission ◽  
Zno Nanowires ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Emission Properties ◽  
Field Emission Properties

scholarly journals Non-monotonous size-dependent photoluminescence and excitonic relaxations in nanostructured ZnO thin films

RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 2180-2188 ◽  
Author(s):  
Ashish C. Gandhi ◽  
Ching-Hao Liao ◽  
Wei-Li Yeh ◽  
Yue-Lin Huang
Keyword(s):  
Thin Films ◽  
Green Emission ◽  
Band Edge ◽  
Dead Layer ◽  
Zno Thin Films ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Size Dependent

To comprehensively understand the behaviors of the near-band-edge emission and green emission (NBE, GE), the volume-weighting (VW) model is adapted to take into account a dead layer of confined excitons.

Photoluminescence and Raman Studies of Annealed ZnO Nanostructures

2012 ◽  
Vol 501 ◽  
pp. 179-183 ◽  
Author(s):  
Siti Khadijah Mohd Bakhori ◽  
Chuo Ann Ling ◽  
Shahrom Mahmud
Keyword(s):  
Optical Signal ◽  
High Mode ◽  
Raman Shift ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Zno Nanostructures ◽  
Zno Nanostructure ◽  
Band Emission ◽  
Crystallite Sizes ◽  
Tem Microscopy

The influence of annealing on the optical properties of as-grown ZnO nanostructures prepared in pellets has been investigated by photoluminescence (PL) and Raman spectroscopy. The annealing temperatures of ZnO nanostructure at 600°C, 650°C and 700 °C were conducted in oxygen (O2) and nitrogen (N2) ambient. The near band edge emission (NBE) of samples recorded in the PL spectra demonstrates significant changes on optical signal whereby the NBE is redshifted after O2 annealed and became slightly higher in N2 annealed. Apart from that, weak green luminescence (GL) namely deep band emission (DBE) is observed centre at 532.95 nm (2.23 eV) and 511.00 nm (2.42 eV) for annealed in O2 and N2 respectively, whereas lower DBE observed in as-grown ZnO. On the other hand, Raman shift reveal the phonon mode of the ZnO nanostructures and the E2 (high) mode were downshifted as annealed in O2 ambient, and upshifted in N2 ambient. The downshift and upshift of the E2 (high) mode are correlated to tensile and compressive stress. Moreover the crystallite sizes were calculated from FWHM of XRD and TEM microscopy reveals the nanoplates structure of ZnO nanostructures.

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