Mr
Emmanuel Igumbor
(University of Pretoria)
05/05/2015, 15:15
SACPM
Poster Presentations
As a result of its narrow band gap, high carrier mobility and low voltage operation the application of Germanium (Ge) as a promising material for complementary metal-oxide semiconductors (CMOS) technology is attracting attention recently [1]. Studies on Several defects including self-interstitials, interstitials, vacancies and vacancy complexes [2-3] have been carried out. For Silicon,...
Dr
Kashma Sharma
(Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300, Republic of South Africa)
05/05/2015, 15:15
SACPM
Poster Presentations
Mr
Meehleketo Advice Mayimele
(university of Pretoria)
05/05/2015, 15:15
SACPM
Poster Presentations
We report on the analysis of current voltage (I-V) measurements performed on Pd/ZnO Schottky barrier diodes in the 30-350 K temperature range. Assuming thermionic emission (TE) theory, the forward bias I-V characteristics were analysed to extract Pd/ZnO Schottky diode parameters. Comparing Cheung’s method in the extraction of the series resistance with Ohm’s law, it was observed that at lower...
Ms
zamaswazi portia Tshabalala
(DST/CSIR National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, Pretoria, 0001, South Africa)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
The need for gas sensors to monitor and detect toxic, explosive and combustible gases in mines and in the environment has stimulated researchers to develop portable gas sensing devices that can detect at low concentration and at room temperature. Monitoring such gases can help to prevent occurrences of fatal accidents such as fire and explosions [1].
Amongst the...
Mr
Trilok Pathak
(Gurukula Kangri University, Haridwar, India)
, Dr
Vinod Kumar
(Department of Physics, University of the Free state, Bloemfontein, ZA-9300)
05/05/2015, 15:15
SACPM
Poster Presentations
Zinc oxide (ZnO) is a multifunctional material with unique physical and chemical properties as well as good photo stability.In present work we study the nitrogen doping effect on conductivity and optical properties.
Dr
Moges Tsega Yihunie
(University of the Free State)
05/05/2015, 15:15
SACPM
Poster Presentations
We have investigated the concept of defect in CuxZnSnSe4 (x= 1.62.0) and Cuy(Zn0.9Sn1.1)Se4 (y= 1.6-2.0) bulks prepared by liquid-phase sintering at 600 oC for 2 h with soluble sintering aids of Sb2S3 and Te. All CuxZnSnSe4 pellets exhibited p-type conductivity regardless of Cu contents but Cuy(Zn0.9Sn1.1)Se4 pellets show p-type at y=1.6 and n-type at y= 1.8-2.0. SEM surface images showed the...
Mr
Setumo Victor Motloung
(University of the Free State (Qwaqwa Campus))
05/05/2015, 15:15
SACPM
Poster Presentations
The XRD data revealed that all annealed samples consist of the pure cubic MgAl2O4 structure. The estimated crystallites size were in the range of 12.1 – 11.0 nm in diameter. SEM results showed that the dopant type and varying the Cr3+ concentration in the co-activated samples influences the surface morphology of the phosphor. The PL results showed that the host, 0.1% Cr3+ and Eu3+ activated...
Mr
Ezekiel Omotoso
(University of Pretoria)
05/05/2015, 15:15
SACPM
Poster Presentations
The effect of low-temperature alpha-particle irradiation on Pd/4H-SiC Schottky barrier diodes has been investigated. The motivation is to study the radiation damage of the sample after bombarded with 1.6 MeV a-particles [(He)^(2+)] at 20 K and the annealing of the radiation-induced defects taking place with increasing in temperature. The of fluence alpha-particles amounted to 3 × (10)^(13)...
Prof.
Jorma Hölsä
(University of Turku)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
Impurities and dopants’ inappropriate valences may deteriorate the performance of luminescent materials, cause waste of the high purity (rare earth) material and then incur significant financial losses [1]. The methods used to detect elements’ valence (XPS, Mössbauer and XANES) are not sensitive enough for low concentrations and EPR is not suitable for powders. Obtaining...
Ms
Katekani Shingange
(CSIR and UFS)
05/05/2015, 15:15
SACPM
Poster Presentations
In this work, low dimensional ZnO nanorods with different sizes were successfully prepared using a microwave-assisted hydrothermal method. The influence of the microwave reaction time on the structural, and luminescence properties of the ZnO nanorods was studied using X-ray diffraction (XRD), Scanning electron microscope (SEM), and photoluminescence (PL). XRD analysis showed that all samples...
Dr
Danilo Mustafa
(University of São Paulo)
05/05/2015, 15:15
SACPM
Poster Presentations
Self-assembled luminescent LDH nanotubes (Ø 20nm) combine the potential of RE3+ containing LDH with a high surface area and easily accessible mesopores (±175 m2/g; 0.75 cm3/g) suitable for hosting large sensitizing dyes and other interesting photonic species such as luminescent nanodots.
Dr
Durgaprasad Ramteke
(Department of Physics, University of the Free State)
05/05/2015, 15:15
SACPM
Poster Presentations
Mr
ALI HALAKE WAKO
(University of the Freestate)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
Long afterglow or persistent phosphors have the ability of absorbing energy from UV or sunlight and then release it slowly in the dark [1,2]. Inorganic phosphors doped with rare earth elements show broad band emission from blue to red which makes them suitable for a variety of industrial applications, such as luminescent pigments, fluorescent lamps, color display, plasma...
Mr
Lehlohonolo Koao
(UFS (Qwa Qwa Campus))
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
With a wide band gap of 3.4 eV and a large exciton binding energy of 60 meV at room temperature, ZnO is attractive for blue and ultra-violet optoelectronic devices, and transparent conducting oxide films for photovoltaic applications. The large excitonic binding energies of ZnO and ZnS could enable efficient excitonic emission at temperatures well above room temperature and...
Ms
Leandre' Brandt
(University of the Western Cape)
05/05/2015, 15:15
SACPM
Poster Presentations
Mr
Shandirai Tunhuma
(University of Pretoria)
05/05/2015, 15:15
SACPM
Poster Presentations
We investigated the rectification properties of Gold Schottky contacts fabricated on epitaxial n-type GaAs.The study was carried out using Laplace deep level transient spectroscopy together with the current-voltage characteristics and the capacitance voltage characteristics in the 80-480K range.
Prof.
Ernest van Dyk
(NMMU)
05/05/2015, 15:15
SACPM
Poster Presentations
The progression of the development of High Concentrated Photovoltaic (H-CPV) technology promises lower costs and higher cell and module efficiencies. However, development is limited by various materials and device aspects. One of these, the power production limiting effects of the optical system on a Concentrator Triple Junction (CTJ) cell in an H-CPV module, is the focus of this paper. With...
Mrs
Kewele Emily Foka
(University of the Fee Stae)
05/05/2015, 15:15
SACPM
Poster Presentations
The effect of urea ratio on structural and luminescence properties of YVO4:Dy phosphor
1. Introduction
Although the luminescence characteristics of vanadates phosphors have been reported, yttrium vanadates (YVO4) are good host materials for luminescence efficiency. Like Eu, Tm and other rare earth ions, Dy can also act as a useful activator. Many researchers have reported that YVO4...
Mr
ABDUB ALI
(UNIVERSITY OF THE FREE STATE)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
Eu3+- doping has been of interest to improve the luminescent characteristics of thin-film phosphors. Europium-doped Y2O2S exhibits strong UV and cathode ray-excited luminescence, so it is widely used as red phosphors for low-pressure fluorescent lamps, cathode-ray tubes and plasma display panels [1]. Also, the hexagonal Y2O2S is a good host material for rare earth ions. In...
Ms
Zuraan Paulsen
(Unversity of the Western Cape)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
Magnetic luminescent nanoparticles have shown great promise in various biomedical applications namely: contrast agents for magnetic resonance imaging, multifunctional drug carrier system, magnetic separation of cells, cell tracking, immunoassay, and magnetic bioseparation. However most of these nanoparticles are cadmium- based. Indium- phosphide is known to be less toxic...
Mr
Raphael Nyenge
(University of the Free State and Kenyatta University)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
Red-emitting alkali earth sulfide phosphor such as divalent europium (Eu2+) doped calcium sulfide (CaS: Eu2+) is a good material for blue pumped three-band phosphor-converted white LEDs since it has strong absorption in the blue region [1]. CaS: Eu2+ thin films were deposited on Si (100) substrates using the pulsed laser deposition technique to investigate the effect of...
Mr
Nambinintsoa Romeoh HASINJATOVO MANDANIRINA
(Nelson Mandela Metropolitan University)
05/05/2015, 15:15
SACPM
Poster Presentations
1. Introduction
In recent years, many studies have been reported on the optical response characterization of type-II GaSb/GaAs quantum dot solar cells [1-2]. It has been shown that incorporating quantum structures into the junction can considerably extend the near band-edge response of the solar cell [2]. Unlike with conventional response measurements, where the intensity of the light source...
Dr
Zelalem N. URGESSA
(NMMU)
06/05/2015, 13:30
SACPM
Poster Presentations
In this study a controlled examination was undertaken in order to confirm and compare the parameters affecting PS-b-PMMA copolymer thin film nano-masks. A PS-b-PMMA copolymer with a molecular weight of 67 100 g.mol-1 (70:30) was used to produce thin film nano-masks on treated and untreated Si substrates. By simultaneously annealing samples of differing thin film thicknesses on the two types of...
Mr
Geoffrey Webb
(University of Pretoria)
06/05/2015, 13:30
SACPM
Poster Presentations
We are investigating the possibility of the Antimony-Vacancy complex (E-center) using the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional within density functional theory (DFT). The results are then compared the predictions we obtained to experimental observations. We have in the past observed interesting results for the similar case of metastability in the Boron – Vacancy complex in silicon...
Mr
Crispin Munyelele Mbulanga
(Nelson Mandela Metropolitan University)
06/05/2015, 13:30
SACPM
Poster Presentations
Mr
Fred Joe Nambala
(University of Pretoria)
06/05/2015, 13:30
SACPM
Poster Presentations
1. Introduction
Zinc Oxide (ZnO) has been attracting much attention in research activities for applications in light emitting diodes, spintronic devices, solar cells, etc. [1]. Doping the ZnO changes its properties especially in increasing its electrical conductivity [2]. This work focuses on the development of Aluminium doped Zinc Oxide (AZO) which has property-integrity to allow a...
Mr
Phuti Ngoepe
(University of Pretoria)
06/05/2015, 13:30
SACPM
Poster Presentations
Aluminum gallium nitride (AlxGaxN) is a ternary wide direct bandgap semiconductor. The Al to Ga ratio can be varied to achieve various bandgap ranging from 3.4 eV for pure GaN to 6.2 eV for pure AlN. This property makes AlGaN based devices suitable for light emitting and light detecting devices such as LED’s and photodiodes. In fabricating a device such as a Schottky diode the metals deposited...
Mr
Jatani Ungula
(University of the Free State)
06/05/2015, 13:30
SACPM
Poster Presentations
The abstract gives an overview of the content of my paper entitled, “Effect of solvent medium on material properties of ZnO nanoparticles synthesized by sol-gel method.”
The issues on applications, optical and luminescence properties and the structure of ZnO were mentioned in introduction. In addition, the abstract reports that, in the research, high-quality zinc oxide (ZnO) nanoparticles...
Ms
Helga Danga
(University of Pretoria)
06/05/2015, 13:30
SACPM
Poster Presentations
Silicon (Si) is one of the most important semiconductor materials and it has been studied extensively. This is mainly due to its low cost, thermal stability, and good durability. It is because of these properties that Si is a suitable candidate for exploring the electron beam exposure (EBE) technique. The main aim of developing the EBE technique was to see if electron beam deposition (EBD)...
Mr
Matshisa Legodi
(University of Pretoria)
06/05/2015, 13:30
SACPM
Poster Presentations
Dr
Ted Kroon
(University of the Free State)
06/05/2015, 13:30
SACPM
Poster Presentations
Energy transfer phenomena can play an important role in the development of luminescence materials. For example, in co-doped silica samples the Tb ions producing green luminescence useful in a variety of lighting and display applications can be excited indirectly by energy transfer from the Ce ions which have a longer, more acccessible excitation wavelength. As a result of energy tranfer away...
Prof.
Jorma Hölsä
(University of Turku)
06/05/2015, 13:30
SACPM
Poster Presentations
1. Introduction
The Eu2+ and R3+ doped alkaline earth aluminates (MAl2O4; M: Ca, Sr, Ba) are among the best persistent luminescence materials [1]. The most efficient is, however, SrAl2O4:Eu2+,Dy3 – partly due to its emission in green to which the human eye is sensitive. Also the blue emitting CaAl2O4:Eu2+,Nd3+ is more efficient than the barium one. All three materials should have...
Dr
Abdelrhman Mohmmed
(University of the Free State)
06/05/2015, 13:30
SACPM
Poster Presentations
In recent years, there has been growing importance focused on research in light emitting diodes (LEDs) because of their long operation lifetime, energy-saving feature and high material stability [1, 2]. During the past few years, white LEDs fabricated using a near ultraviolet (n-UV) LED (380–420 nm) coupled with red, green, and blue phosphors have attracted much attention [2]. Accordingly, it...
Dr
Vijay Kumar
(Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300, Republic of South Africa)
06/05/2015, 13:30
SACPM
Poster Presentations
Mr
Funda Mpanza
(Heriot-Watt University)
06/05/2015, 13:30
SACPM
Poster Presentations
Dr
Gugu Mhlongo
(CSIR)
06/05/2015, 13:30
SACPM
Poster Presentations
Undoped and Pd (0.5 and 0.75 mol%) doped ZnO nanostructures were synthesized by a sol-gel method and annealed at 350 oC. An increase in the particle size with Pd doping was observed. Room-temperature PL measurements showed that both oxygen and zinc related defects played a role in the defect emission process. PL and sensing analyses revealed that there is a correlation between the sensing...
Ms
Roz Madihlaba
(University of the Western Cape)
06/05/2015, 13:30
SACPM
Poster Presentations
Recently, great efforts have been made to develop efficient phosphor systems. Among these, a number of works have been carried out on investigations of the luminescent properties for borates, aluminates and gannets [1, 2]. Since the first white light emitting diodes(W-LED’s) became commercially available, it have attracted great attention for their obvious advantages such as long lifetime,...
Ms
Maabong Kelebogile
(University of Pretoria)
06/05/2015, 13:30
SACPM
Poster Presentations
Metal oxides have attracted a considerable attention as transparent electrodes, active layers and charge collectors in energy harvesting activities due to their diverse properties [1]. Due to its a nearly ideal band gap (~ 2.1 eV) for solar energy conversions, low cost, chemical stability, natural abundance, n-type conductivity, “rust”- iron oxide (α-Fe2O3) - is regarded as a promising...
Mr
Simon. N Ogugua
(UNIVERSITY OF THE FREE STATE)
06/05/2015, 13:30
SACPM
Poster Presentations
1. Introduction
Nowadays, phosphors have found applications in solid state lighting, phototherapy, information display technologies, and solar cells, among other things. Rare earth oxyorthosilicates of the form R2SiO5 (R = La, Gd, Y) doped with rare earth elements, have been of interest for the past decades due to their wide band gap, fast decay times, high quantum efficiency, high density...
Prof.
Francis Dejene
(University of the Free Stet)
06/05/2015, 13:30
SACPM
Poster Presentations
Introduction
Solar water treatment is a low-technology solution that works to capture the heat and energy from the sun to make water cleaner and healthier for human use and consumption. The oxide nanoparticles synthesized by several methods appears more and more useful because these nanoparticles have good electrical, optical and magnetic properties that are different from their bulk...
Mr
Tero Laihinen
(University of Turku, Department of Chemistry, Turku, Finland)
06/05/2015, 13:30
SACPM
Poster Presentations
In up-conversion luminescence, the absorption of two or more low energy photons is followed by the emission of a high energy photon. NaYF4:Yb3+,R3+ (R: Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er or Tm) materials were prepared to study up-conversion luminescence. The materials were studied with TG-DSC, FTIR and XPD methods. Up-conversion luminescence was studied with NIR laser excitation at 976 nm. The DSC...
Ms
Sharon Kiprotich
(University of the Free State)
06/05/2015, 13:30
SACPM
Poster Presentations
The title of the abstract is “The influence of reaction times on structural, optical and luminescence properties of CdTe nanoparticles prepared by wet-chemical process”
In introduction, the abstract reports the study of CdTe nanoparticles made by a simple green synthesis using L-cystein as a capping agent, potassium tellurite and sodium selenosulphate as stable tellurium and selenium sources....
Dr
Pontsho Mbule
(University of South Africa)
06/05/2015, 13:30
SACPM
Poster Presentations
Zinc silicate (Zn2SiO4) is a good host lattice for luminescence centers such as rare-earth ions and transition metals (TM) to prepare light emitting materials (phosphors) that can emit blue, green and red light upon excitation with high energy electrons or photons. In this work, combustion method was used to prepare undoped and manganese (Mn2+) and thulium (Tm3+)–co-activated zinc silicate...
