Synthesis of DI- and trialkylthiourea complexes of Cd, Mn and Ni as precursors for phosphonoacetic acid (PAA)-capped metal sulphide nanoparticles

Many studies on thiourea and its derivatives in different metal (II) complexes have confirmed that coordination is through the sulphur atom. The bonding of substituted thioureas to different metals was confirmed with a combination of spectroscopic studies such as IR and NMR spectroscopy and elemental analysis. A series of metal (II) di- and trialkylthioureas complexes have been synthesized and characterized. Their bonding through sulphur atoms rendered these complexes good precursors for the preparation of metal sulphide nanoparticles. Thermogravimetric analysis on the complexes was undertaken to check their suitability as precursors for the synthesis of nanoparticles and their potential as precursors for metal sulphide thin films using the chemical vapour deposition (CVD) technique and their general chemical and thermal stability. All the complexes reported in this work were used as single source molecular precursors for the synthesis of cadmium, manganese and nickel sulphide nanoparticles. In this study the investigation on the influence of capping agent and temperature on the size and morphology of nanoparticles was undertaken. Nanoparticles obtained by thermolysis of precursors in phosphonoacetic acid (PAA) were bigger in size and rod-shaped compared to smaller rods obtained in hexadecylamine (HDA). CdS nanoparticles prepared using PAA as a capping agent showed a huge blue-shift of the band edge from the bulk of 515 nm, compared to CdS nanoparticles obtained using HDA as a capping agent. When PAA was mixed with trioctylphosphine oxide (TOPO), a blue shift of band edges in all the bulk materials of different metal sulphides prepared was observed and the rod-shaped nanoparticles changed to spherical particles

Structural, morphological, optical and electrical properties of Schottky diodes based on CBD deposited ZnO : Cu nanorods

Undoped and copper doped zinc oxide (ZnO) nanorods have been synthesized by a simple chemical bath deposition (CBD) method at a temperature of 90 C. Structural, morphological, optical and electrical properties of the synthesized ZnO nanorods were found to be dependent on the Cu doping percentage. X-ray diffraction (XRD) patterns revealed strong diffraction peaks of hexagonal wurtzite of ZnO, and no impurity phases from metallic zinc or copper. Scanning electron microscopy (SEM) images showed changes in diameter and shape of nanorods, where by those doped with 2 at.% and 3 at.% aggregated and became compact. Selected area electron diffraction (SAED) patterns indicates high quality, single crystalline wurtzite structure ZnO and intensities of bright spots varied with copper doping concentration. UVevisible absorption peaks of ZnO red shifted with increasing copper doping concentration. Raman studies demonstrated among others, strong and sharp E2 (low) and E2 (high) optical phonon peaks confirming crystal structure of ZnO. Current-voltage measurements based on the gold/ZnO nanorods/ITO showed good rectifying behavior of the Schottky diode. The predicted Schottky barrier height of 0.60 eV was obtained which is not far from the theoretical Schottky-Mott value of 0.80 eVThe University of Pretoria and National Research Foundation (NRF), South Africa, Grant No: 91550 and 94166.http:// www.elsevier.com/locate/superlattices2018-07-31hb2017Physic

Migration behaviour of Europium implanted into single crystalline 6H-SiC

Migration behaviour of Europium (Eu) implanted into 6H-SiC was investigated using Rutherford backscattering spectroscopy (RBS), RBS in a channelling mode (RBS-C) and scanning electron microscopy (SEM). Eu ions of 360 keV were implanted into 6H-SiC at 600 °C to a fluence of 1 × 1016 cm−2. The implanted samples were sequentially annealed at temperatures ranging from 1000 to 1400 °C, in steps of 100 °C for 5 h. RBS-C showed that implantation of Eu into 6H-SiC at 600 °C retained crystallinity with some radiation damage. Annealing of radiation damage retained after implantation already took place after annealing at 1000 °C. This annealing of radiation damage progressed with increasing annealing temperature up to 1400 °C. A shift of Eu towards the surface took place after annealing at 1000 °C. This shift became more pronounced and was accompanied by loss of Eu from the surface at annealing temperatures >1000 °C. This shift was accompanied by broadening of Eu peak/Fickian diffusion after annealing at temperatures >1100 °C. The migration of Eu occurring concurrently with the annealing of radiation damage was explained by trapping and de-trapping of Eu by radiation damage.The National Research Foundation (NRF) (grant no: 94104) of South Africahttp://www.journals.elsevier.com/vacuum2018-07-30hj2017Physic

Slow and swift heavy ions irradiation of zirconium nitride (ZrN) and the migration behaviour of implanted Eu

Please read abstract in the article.http://www.elsevier.com/locate/nimb2020-12-15hj2020Physic

Improved efficiency of organic solar cells using Au NPs incorporated into PEDOT:PSS buffer layer

Au based plasmonic phenomenon inside the hole transport layer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) of an organic solar cell based on blend of poly(3-hexylthiophene) (P3HT) and [6:6]-phenyl-C61-butyric acid (PCBM) is investigated. The concentration of the Au nanoparticles synthesized by wet chemical reduction is one of the key factors to strong light trapping when the spherical gold nanoparticles are blended into the PEDOT:PSS solution. Studies of the influence of the concentration of nanoparticles distribution in the PEDOT:PSS were carried out using UV–Vis spectroscopy and atomic force microscopy. Electrical characteristics of the pristine device and of device with metallic nanostructures were analyzed from J –V characteristics to observe the plasmonic effects on the performance in the P3HT:PCBM organic solar cells. The origin of the photocurrent enhancements with varying Au nanoparticles concentrations on PEDOT:PSS are discussed.The University of theWitwatersrand, Material Physics Research Institute, School of Physics & Chemistry; and MMU facilities at Wits, NRF and Material Energy Research Group (MERG).http://scitation.aip.orgcontent/aip/journal/advaam2017Physic

Effect of thermal annealing on SHI irradiated indium implanted glassy carbon

Please read abstract in the article.The National Research Foundation (NRF) of South Africa and the University of Pretoria.http://www.elsevier.com/locate/nimb2022-06-22hj2022Materials Science and Metallurgical EngineeringPhysic

Structural modification of indium implanted glassy carbon by thermal annealing and SHI irradiation

Please read abstract in the article.The National Research Foundation (NRF) (grant no. 110363) of South Africahttp://www.journals.elsevier.com/vacuum2018-10-30hj2017Physic

Effects of Ag and Sr dual ions implanted into SiC

Please read abstract in the article.National Research Foundation of South Africa, Knowledge Interchange and Collaboration Programme (KIC).http://www.elsevier.com/locate/nimbhj2021Physic

Effect of sequential isochronal annealing on the structure and migration behaviour of selenium-ion implanted in glassy carbon

Please read abstract in the article.http://www.journals.elsevier.com/vacuumhj2021Physic

Elucidating the structural properties of gold selenide nanostructures

Please read abstract in the article.Mintek and NRFhttp://rsc.li/njc2020-03-14hj2020Physic