Deposition of Zinc Oxide Thin Films Using a Surface Reaction on Platinum Nanoparticles

2011 ◽  
Vol 1315 ◽  
Author(s):  
Kanji Yasui ◽  
Hitoshi Miura ◽  
Hiroshi Nishiyama
Keyword(s):  
Free Exciton ◽  
Exothermic Reaction ◽  
Chemical Vapor ◽  
Band Edge ◽  
Chemical Vapor Deposition Method ◽  
Zno Films ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Neutral Donor ◽  
Pl Spectra

ABSTRACTA new chemical vapor deposition method for the growth of ZnO films using the reaction between dimethylzinc (DMZn) and thermally excited H2O produced by a Pt-catalyzed H2–O2 reaction was investigated. The thermally excited H2O molecules formed by the exothermic reaction of H2 and O2 on the catalyst were ejected from a fine nozzle into the reaction zone and allowed to collide with DMZn ejected from another fine nozzle. The ZnO films were grown directly on a-plane (11-20) sapphire substrates at substrate temperatures of 773-873 K with no buffer layer. X-ray diffraction patterns exhibited intense (0002) and (0004) peaks from the ZnO(0001) index plane. The smallest full width at half maximum (FWHM) value of the ω- rocking curve of ZnO(0002) was less than 0.1º. The largest Hall mobility and the smallest residual carrier concentration of the ZnO films were 169 cm2V−1s−1 and 1.7×1017 cm−3, respectively. Photoluminescence (PL) spectra at room temperature exhibited a band edge emission at 3.29 eV, with a FWHM of 104 meV. Green luminescence from deeper levels was generally about 1.5% of the band edge emission intensity. PL spectra at 5 K showed a strong emission peak at 3.3603 eV, attributed to the neutral donor-bound exciton Dºx. The FWHM was as low as 1.0 meV. Free exciton emissions also appeared at 3.3757 eV (FXA, n=1) and 3.4221 eV (FXA, n=2).

Chemical Vapor Deposition of Porous GaN Particles on Silicon

2012 ◽  
Vol 18 (4) ◽  
pp. 905-911 ◽  
Author(s):  
Joan J. Carvajal ◽  
Oleksandr V. Bilousov ◽  
Dominique Drouin ◽  
Magdalena Aguiló ◽  
Francesc Díaz ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Band Edge ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Si Substrates ◽  
Internal Morphology ◽  
Simple Chemical

AbstractWe present a technique for the direct deposition of nanoporous GaN particles on Si substrates without requiring any post-growth treatment. The internal morphology of the nanoporous GaN particles deposited on Si substrates by using a simple chemical vapor deposition approach was investigated, and straight nanopores with diameters ranging between 50 and 100 nm were observed. Cathodoluminescence characterization revealed a sharp and well-defined near band-edge emission at ∼365 nm. This approach simplifies other methods used for this purpose, such as etching and corrosion techniques that can damage the semiconductor structure and modify its properties.

Structural, optical and magnetic properties of highly oriented transition metal (Mn/Co/Ni/Cu) doped ZnO thin films prepared by PLD

2012 ◽  
Vol 1454 ◽  
pp. 239-244 ◽  
Author(s):  
Arun Aravind ◽  
M.K. Jayaraj ◽  
Mukesh Kumar ◽  
Ramesh Chandra
Keyword(s):  
Thin Films ◽  
Transition Metal ◽  
Room Temperature Ferromagnetism ◽  
Visible Region ◽  
Band Edge ◽  
Zno Films ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Axis Orientation ◽  
Doped Zno

ABSTRACTZnO doped with transition metal (TM) thin films were grown by pulsed laser deposition. XRD pattern reveals that all the ZnTMO films have c-axis orientation normal to the substrate. The reciprocal space mapping shows that the crystallinity of ZnTMO film deteriorates at higher doping of TM. All the TM doped ZnO films have transmittance greater than 75% in the visible region. The band gap of the ZnTMO thin films shows red shift on doping with Ni and Cu where as blue shift is observed for Co and Mn which increases with TM concentration. The copper doped ZnO thin film shows green PL emission at 542 nm along with the band edge emission at 385 nm. But other TM doping shows only band edge emission (385nm) and its intensity decreases at higher doping percentage. The presence of non-polar E2high and E2lowRaman modes in thin films indicates that ‘TM’ doping do not alter the wurtzite structure of ZnO. The magnetic studies of the TM doped ZnO shows room temperature ferromagnetism

Photoluminescence of ZnO Nanocrystals Embedded in BaF2 Matrices by Magnetron Sputtering

2008 ◽  
Vol 8 (3) ◽  
pp. 1160-1164
Author(s):  
C. H. Zang ◽  
Y. C. Liu ◽  
R. Mu ◽  
D. X. Zhao ◽  
J. Y. Zhang ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Raman Scattering ◽  
Free Exciton ◽  
Wide Band ◽  
Zno Films ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Ultraviolet Emission ◽  
Pl Spectra ◽  
Zno Nanocrystals

This paper describes ZnO nanocrystals embedded in BaF2 matrices by the magnetron sputtering method in an attempt to use fluoride as a shell layer to embed ZnO nanocrystals core. BaF2 is a wide-band gap material, and can confine carriers in the ZnO films. As a result, the exciton emission intensity should be enhanced. The sample was annealed at 773 K, and X-ray diffraction (XRD) results showed that ZnO nanocrystals with wurtzite structure were embedded in BaF2 matrices. Raman-scattering spectra also confirmed the formation of ZnO nanoparticles. Abnormal longitudinal-optical (LO) phonon-dominant multiphonon Raman scattering was observed in the sample. Room-temperature photoluminescence (PL) spectra showed an ultraviolet emission peak at 374 nm. The origin of the ultraviolet emission is discussed here with the help of temperature-dependent PL spectra. The ultraviolet emission band was a mixture of free exciton and bound exciton recombination observed in the low temperature PL spectra (at 77 K). Abnormal temperature dependence of ultraviolet near-band-edge emission-integrated intensity of the sample was observed. The band tail state was observed in the absorption spectra, illustrating that the impurity-related defects were caused by the shell of the BaF2 grain layer. For comparison, ZnO films on BaF2 substrates were also fabricated by the magnetron sputtering method, and the same measurement methods were used.

The compositional and optical characterizations of InGaAsN alloy semiconductor grown by MOVPE

2002 ◽  
Vol 744 ◽  
Author(s):  
Sakuntam Sanorpim ◽  
Fumihiro Nakajima ◽  
Ryuji Katayama ◽  
Kentaro Onabe ◽  
Yashihiro Shiraki
Keyword(s):  
Room Temperature ◽  
Excitation Power ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Optical Investigation ◽  
Edge Emission ◽  
Alloy Films ◽  
Pl Spectra

ABSTRACTWe report on the compositional and optical investigation of InGaAs(N) alloy films grown on GaAs (001) substrates by low-pressure (60 Torr) metalorganic vapor phase epitaxy (MOVPE). The alloy films with the room-temperature photoreflactance (PR) signal (Eo transition) wavelength range of 0.98–1.36 m have been grown. The variation in PL characteristics of the InGaAs(N) alloy films has been investigated as a function of alloy composition, excitation power and temperature. At low temperatures (T<100K), the PL spectra with several sub-peaks include localization emission as well as near-band-edge emission. On the other hand, the room-temperature PL properties for InxGa1-xAs1-yNy (x = 10.5% and 17.0% and y < 2%) are excellent with a single near-band-edge emission peak corresponding to their own Eo transition. The evolution of PL spectra with excitation power and temperature led to an insight into the nature of the near-band-edge states. The temperature dependence of integrated PL intensity indicates the presence of a large density of non-radiative recombination centers, showing a behavior characterized by two activation energies. Our results suggest that the origin of localization in InGaAsN alloy films is the alloy inhomogeneities of both In and N, which may results in the characteristic carrier dynamics.

Properties of Different Room-Temperature Photoluminescence Bands in 4H-SiC Substrates Investigated by Mapping Techniques

2007 ◽  
Vol 556-557 ◽  
pp. 411-414
Author(s):  
Bharat Krishnan ◽  
Sashi Kumar Chanda ◽  
Yaroslav Koshka
Keyword(s):  
Room Temperature ◽  
Free Exciton ◽  
Band Edge ◽  
Reverse Correlation ◽  
Band Edge Emission ◽  
Free Electron Concentration ◽  
Edge Emission ◽  
Room Temperature Photoluminescence ◽  
Mapping Techniques ◽  
Commercial Nitrogen

The room-temperature photoluminescence (RTPL) was investigated in commercial nitrogen-doped 4H-SiC substrates. In a typical RTPL spectrum of n-type 4H-SiC substrate, the ‘band-edge’ emission was similar to PL signatures that are typically attributed to free-exciton recombination in high-quality thick epitaxial layers. The origin of the deep-defect ‘red’ emission and its influence on recombination properties of SiC remain unclear. In most of the substrates in which the ‘red’ RTPL band was strong, clear reverse correlation between the ‘red’ and ‘band-edge’ RTPL intensities was observed. In contrast, direct correlation was observed between the ‘bandedge’ PL map and distribution of the net free electron concentration. There is a possibility that incorporation of nitrogen donors is influenced by (or influences) incorporation of lifetime-limiting deep defects.

scholarly journals Annealing Behavior of The Photoluminescence Lines in CdTe and Znx Cd1−x Te Single Crystals

1989 ◽  
Vol 161 ◽  
Author(s):  
J. Gonzalez-Hernandez ◽  
A. Reyes-Mena ◽  
Elias Lopez-Cruz ◽  
D.D. Allred ◽  
Worth P. Allred
Keyword(s):  
Single Crystals ◽  
Mixed Crystals ◽  
Band Edge ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Photoluminescence Spectra ◽  
Edge Emission ◽  
Annealing Behavior ◽  
Pl Spectra ◽  
Compositional Range

ABSTRACTThe main lines in the photoluminescence spectra of Zn1Cd1−xTe single crystals grown by a modified Bridgman method in the compositional range of 0 ≤ X ≤ 0.25 have been identified. All crystals show only near-band-edge emission. To assist in the identification, various samples with different compositions were annealed under a Cd atmosphere. In the pure crystals, the prominent (A°,X) bound exciton line, as well as the doublet at longer wavelengths, disappear after the annealing. In contrast, the treatments do not change significantly the PL spectra of the mixed crystals.

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

Nitride-Rich Hexagonal GaNP Growth Using Metalorganic Chemical Vapor Deposition

2000 ◽  
Vol 639 ◽  
Author(s):  
Seikoh Yoshida ◽  
Yoshiteru Itoh ◽  
Junjiroh Kikawa
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Different Temperatures ◽  
Metalorganic Chemical

ABSTRACTThe growth of GaNP using laser-assisted metalorganic chemical vapor deposition (LA-MOCVD) was carried out for the fabrication of a light-emitting diode (LED). We used an Ar-F laser in order to decompose the source gases at lower temperatures. Trimethylgallium (TMG), ammonia (NH3) and tertialybuthylphosphine (TBP) were used for the growth. GaNP growth was carried out at different temperatures. After that, annealing was carried out at 1273-1373 K to improve the crystal quality.As a result, N-rich GaNP could be grown at 1123-1223 K. The surface morphologies of GaNP were improved when the growth temperature was increased to above 1173 K. We investigated the photoluminescence (PL) of GaNP. The band-edge emission of GaNP was observed at 77 K upon applying thermal annealing at 1323 K. This peak shifted to about 0.2 eV compared with the GaN band-edge emission. Furthermore, a GaNP LED was fabricated and the electoluminescence spectra were investigated. The band-edge emission at 420 nm was observed.

Sign in / Sign up

Export Citation Format

Share Document