Band-edge emission of undoped and doped ZnO single crystals at room temperature

2002 ◽  
Vol 91 (6) ◽  
pp. 3658-3663 ◽  
Author(s):  
Naoki Ohashi ◽  
Takashi Sekiguchi ◽  
Kouichiroh Aoyama ◽  
Takeshi Ohgaki ◽  
Yoshihiro Terada ◽  
...  
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Doped Zno

Band-edge emission, defects, morphology and structure of in-doped ZnO nanocrystal films

2019 ◽  
Vol 89 ◽  
pp. 322-328 ◽  
Author(s):  
B. El Filali ◽  
J.A. Jaramillo Gomez ◽  
T.V. Torchynska ◽  
J.L. Casas Espinola ◽  
L. Shcherbyna
Keyword(s):  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Morphology And Structure ◽  
Nanocrystal Films ◽  
Doped Zno ◽  
Zno Nanocrystal

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

Characteristics of GaN/Si(111) Epitaxy Grown using Al0.1Ga0.9N/AlN Composite Nucleation Layers having Different Thicknesses of AlN

2002 ◽  
Vol 722 ◽  
Author(s):  
Seong-Hwan Jang ◽  
Seung-Jae Lee ◽  
In-Seok Seo ◽  
Haeng-Keun Ahn ◽  
Oh-Yeon Lee ◽  
...  
Keyword(s):  
Room Temperature ◽  
Growth Characteristics ◽  
Band Edge ◽  
Band Edge Emission ◽  
Yellow Luminescence ◽  
Edge Emission ◽  
Etch Pits ◽  
Nucleation Layer ◽  
Sharp Band ◽  
Surface Morphologies

AbstractWe have studied the effects of Al0.1Ga0.9N(150 nm)/AlN Composite Nucleation Layers (CNLs) having different thicknesses of AlN ranging from 20 to 41 nm on the growth characteristics of GaN/Si(111) epitaxy. The surface morphologies of the GaN epitaxial layers which were grown on Al0.1Ga0.9N(150nm)/AlN CNLs showed that the number of thermal etch pits and cracks was abruptly decreased with the increase of AlN thickness from 20 to 35 nm. However, the morphology of GaN epitaxy which was grown on Al0.1Ga0.9N(150 nm)/AlN CNL having AlN of 41 nm thick above 35 nm showed that the number of them was increased again. So, the GaN/Si(111) epitaxy which was grown using Al0.1Ga0.9N(150 nm)/AlN(35 nm) CNL showed the highest crystallinity having the FWHM of 1157 arcsec for the (0002) diffraction. Photoluminescence spectrum at room temperature for GaN/Si(111) epitaxy grown using Al0.1Ga0.9N(150 nm)/AlN(35 nm) CNL showed a sharp band edge emission at 364 nm, which especially doesn't have yellow luminescence related to various defects such as vacancy and dislocation. Meanwhile, the spectra at room temperature for the others showed yellow luminescence at around 580 nm except each band edge emission. Moreover, the FWHM of main exitonic peak at 10 K for the GaN/Si(111) epitaxy which was grown using Al0.1Ga0.9N(150 nm)/AlN(35 nm) CNL is the lowest value of 12.81 meV among them. It is obvious that the Al0.1Ga0.9N(150 nm)/AlN CNL having suitable thickness of AlN plays an important role in improving the crystallinity and optical properties of GaN/Si(111) heteroepitaxy without any defects such as pits and cracks over the surface by reducing the mismatch of thermal expansion coefficient and lattice constant between GaN and Si(111) comparing with AlxGa1-xN or AlN nucleation layer alone.

scholarly journals Strong near band edge emission of (Ce, Yb) co-doped ZnO thin films after high temperature annealing

2017 ◽  
Vol 7 (8) ◽  
pp. 3041 ◽  
Author(s):  
C. L. Heng ◽  
W. Xiang ◽  
W. Y. Su ◽  
H. C. Wu ◽  
Y. K. Gao ◽  
...  
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Band Edge ◽  
Zno Thin Films ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
High Temperature Annealing ◽  
Edge Emission ◽  
Doped Zno ◽  
Co Doped

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

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.

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