Publications

Structural and magnetic properties of Gd-doped ZnO

Year: 2014

Authors: Ioannis Bantounas, Venkatesh Singaravelu, Iman Salem Roqan, Udo Schwingenschloegl

Gd doped ZnO
Density Functional Theory

Vacancy complexes induce long-range ferromagnetism in GaN

Year: 2014

Authors: Zhenkui Zhang, Udo Schwingenschloegl, Iman Salem Roqan

Vacancies
III-V semiconductors
Ferromagnetism
Density functional
Antiferromagnetism

Possible mechanism for d0 ferromagnetism mediated by intrinsic defects

Year: 2014

Authors: Zhenkui Zhang, Udo Schwingenschloegl, Iman Salem Roqan

Zn vacancies
ZnS Nanostructures
Intrinsic Defects
Density Functional Theory

Excitonic localization in AlN-rich AlxGa1−xN/AlyGa1−yN multi-quantum-well grain boundaries

Year: 2014 ISSN:0003-6951

Authors: Idris A. Ajia, P. R. Edwards, Z. Liu, J.C. Yan, R.W. Martin, Iman Salem Roqan

Multiple Quantum Wells
Grain boundaries
Photoluminescence
Excitons

High optical and structural quality of GaN epilayers grown on

Year: 2014

Authors: Mufasila Mumthaz Muhammed, M. Peres, Y. Yamashita, Y. Morishima, S. Sato, N. Franco, K. Lorenz, A. Kuramata, Iman Salem Roqan

III-V semiconductors
Epitaxy
X-Ray Diffraction
Photoluminescence

Neocellularization and neovascularization of nanosized bioactive glass-coated decellularized trabecular bone scaffolds

Year: 2013

Authors: L-C. Gerhardt, K. L. Widdows, M. M. Erol, A. Nandakumar, Iman Salem Roqan, T. Ansari, A. R. Boccaccini

Decellularized Bone
Scaffold
Bioactive glass
Angiogenesis
Coating
Vascular endothelial growth factor
Stereology
Vascularisation

Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

Year: 2013

Authors: Fred P.M. Jjunju, Abraham K. Badu-Tawiah, Anyin Li, Santosh Soparawalla, Iman Salem Roqan, R. Graham Cooks

Ambient Ionization Mass Spectrometry
Petroleum Constituents
Charge Exchange
Ion-Molecule reactions
Polynuclear Aromatics
Fuels

In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

Year: 2013

Authors: Fred P.M. Jjunju, Anyin Li, Abraham K. Badu-Tawiah, Pu Wei, Linfan Li, Zheng Ouyang, Iman Salem Roqan, R. Graham Cooks

Mass Spectrometer
Corrosion Inhibitor

Sequential multiple-step europiumion implantation and annealing of GaN

Year: 2013

Authors: S. M. C. Miranda, P. R. Edwards, K.P. O’Donnell, M. Bockowski, E. Alves, Iman Salem Roqan, A. Vantomme, K. Lorenz

Gallium Nitride
Ion Implantation
Crystal Quality
Europium

High pressure annealing of Europium implanted GaN

Year: 2012

Authors: K. Lorenz, S. M. C. Miranda, E. Alves, Iman Salem Roqan, K.P. O’Donnell, M. Bockowski

GaN
Rare Earth Doping
Europium
Ion Implantation
Rutherford Backscattering Spectrometry
X-ray

Lineshape Engineering in an All-Pass Ring Resonator with Backreflection Coupled to a Symmetrical Fabry–Perot Resonator

Year: 2012

Authors: Vasily A. Melnikov, Iman Salem Roqan

Coupled-mode theory (CMT)
Transfer functions
Resonator

The photoluminescence/excitation (PL/E) spectroscopy of Eu-implanted GaN

Year: 2011

Authors: K.P. O’Donnell, Iman Salem Roqan, K. Wang, K. Lorenz, E. Alves, M. Bockowski

Gallium Nitride
Europium
Ion Implantation
Photoluminescence
Excitation Mechanism

The pro-angiogenic properties of multi-functional bioactive glass composite scaffolds

Year: 2011

Authors: L-C. Gerhardt, K. L. Widdows, M. M. Erol, C. W. Burch, José, A. Sanz- Herrera, I. Ochoa, R. Stämpfli, Iman Salem Roqan, S. Gabe, T. Ansari, A. R. Boccaccini

Angiogenesis
Bioactive glass
Composite scaffold
Vascular endothelial growth factor
Bone
Vascularisation

Ab initio investigation on the magnetic ordering in Gd doped ZnO

Year: 2011

Authors: Ioannis Bantounas, Souraya Goumri-Said, Mohammed Benali Kanoun, Aure´lien Manchon, Iman Salem Roqan, Udo Schwingenschloegl

Ferromagnetism
Magnetic semiconductors

Lattice site location of optical centers in GaN:Eu light emitting diode material grown by organometallic vapor phase epitaxy

Year: 2010

Authors: K. Lorenz, E. Alves, Iman Salem Roqan, K.P. O’Donnell, A. Nishikawa, Y. Fujiwara, M. Bockowski

Photoluminescence
Doping
Light emitting diodes
III-V semiconductors

Identification of the prime optical center in GaN:Eu3+

Year: 2010 ISSN:10

Authors: Jjunju, Fred.P.M., Abraham.K.Badu-Tawiah, Anyin Li, And R. Graham Cooks, Iman S Roqan

Optics
GaN
Eu3+
Physics

Eu Doping of Zincblende GaN by Ion Implantation

Year: 2009

Authors: K. Lorenz, Iman Salem Roqan, N. Franco, K.P. O’Donnell, V. Darakchieva, E. Alves, C. Trager-Cowan, R.W. Martin, D.J. As, M. Panfilova

III-V semiconductors
Rutherford backscattering
X-Ray Diffraction
Cathodoluminescence
Europium
gallium compounds
Ion Implantation
Lattice constants
wide band gap semiconductors

Optical and Structural Properties of Eu-implanted InxAl1-xN

Year: 2009

Authors: I.S. Roqan, K.P. O’Donnell, C. Trager-Cowan, V. Matias, A. Vantomme

Photoluminescence
III-V semiconductors
Ion Implantation
Linewidths
Rutherford backscattering

Structural and Optical Characterization of Eu-implanted GaN

Year: 2009

Authors: K.P. O’Donnell, Iman Salem Roqan, K. Wang, K. Lorenz, E. Alves, M. Bockowski

Ion Implantation
Excitation Mechanism
Europium
Luminescence
Photoluminescence
Gallium Nitride
Photoluminescence/Excitation
PL/E
Spectroscopy
Eu-Implanted Gan
Physics
Electronic
Optical and Magnetic Materials
Atomic and Molecular Physics

Luminescence spectroscopy of Eu implanted zincblende GaN

Year: 2008

Authors: I. S. Roqan, K. P. O’Donnell, C. Trager-Cowan, B. Hourahine, R.W. Martin, K. Lorenz, M. Panfilova, D.J. As, I.M. Watson, E. Alves

Spectroscopy

Publications

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