Angeloski, A, Cortie, MB, Scott, JA, Bordin, DM & McDonagh, AM 2019, 'Conversion of single crystals of a nickel(II) dithiocarbamate complex to nickel sulfide crystals', INORGANICA CHIMICA ACTA, vol. 487, pp. 228-233.View/Download from: UTS OPUS or Publisher's site
Scott, JA, Angeloski, A, Aharonovich, I, Lobo, CJ, McDonagh, A & Toth, M 2018, 'In situ study of the precursor conversion reactions during solventless synthesis of Co9S8, Ni3S2, Co and Ni nanowires.', Nanoscale, vol. 10, no. 33, pp. 15669-15676.View/Download from: UTS OPUS or Publisher's site
Synthesis of Co9S8, Ni3S2, Co and Ni nanowires by solventless thermolysis of a mixture of metal(ii) acetate and cysteine in vacuum is reported. The simple precursor system enables the nanowire phase to be tuned from pure metal (Co or Ni) to metal sulfide (Co9S8, Ni3S2) by varying the relative concentration of the metal(ii) acetate. The growth environment facilitates new insights through in situ characterization using field-emission scanning electron microscopy (FESEM) and thermogravimetric analysis with gas chromatography-mass spectrometry (TGA-GC-MS). Direct observation by FESEM shows the temperature at which nanowire growth occurs and suggests adatoms are incorporated into the base of the growing nanowire. TGA-GC-MS reveals the rates of precursor decomposition and identity of the volatilized ligand fragments during heat-up and at the nanowire growth temperature. Our results constitute a new approach for the selective fabrication of high quality Co9S8 and Ni3S2 nanowires and more importantly provides new understanding of precursor decomposition reactions that support symmetry-breaking growth in nanocrystals by heat-up synthesis.
Angeloski, A, Gentle, AR, Scott, JA, Cortie, MB, Hook, JM, Westerhausen, MT, Bhadbhade, M, Baker, AT & McDonagh, AM 2018, 'From Lead(II) Dithiocarbamate Precursors to a Fast Response PbS Positive Temperature Coefficient Thermistor', INORGANIC CHEMISTRY, vol. 57, no. 4, pp. 2132-2140.View/Download from: UTS OPUS or Publisher's site
Rahman, MA, Scott, JA, Gentle, A, Phillips, MR & Ton-That, C 2018, 'A facile method for bright, colour-tunable light-emitting diodes based on Ga-doped ZnO nanorods.', Nanotechnology, vol. 29, no. 42, pp. 425707-425707.View/Download from: UTS OPUS or Publisher's site
Bottom-up fabrication of nanowire-based devices is highly attractive for oxide photonic devices because of high light extraction efficiency; however, unsatisfactory electrical injection into ZnO and poor carrier transport properties of nanowires severely limit their practical applications. Here, we demonstrate that ZnO nanorods doped with Ga donors by in situ dopant incorporation during vapour-solid growth exhibit superior optoelectronic properties that exceed those currently synthesised by chemical vapour deposition, and accordingly can be electrically integrated into Si-based photonic devices. Significantly, the doping method was found to improve the nanorod quality by decreasing the concentration of point defects. Light-emitting diodes (LEDs) fabricated from the Ga-doped ZnO nanorod/p-Si heterojunction display bright and colour-tunable electroluminescence (EL). These nanorod LEDs possess a dramatically enhanced performance and an order of magnitude higher EL compared with equivalent devices fabricated with undoped nanorods. These results point to an effective route for large-scale fabrication of conductive, single-crystalline ZnO nanorods for photonic and optoelectronic applications.
Tran, TT, Choi, S, Scott, JA, Xu, ZQ, Zheng, C, Seniutinas, G, Bendavid, A, Fuhrer, MS, Toth, M & Aharonovich, I 2017, 'Room-Temperature Single-Photon Emission from Oxidized Tungsten Disulfide Multilayers', Advanced Optical Materials, vol. 5, no. 5, pp. 1-5.View/Download from: UTS OPUS or Publisher's site
Robust quantum emitters fabricated by thermal oxidation of tungsten disulfide multilayers are reported. The emitters show robust, optically stable, linearly polarized luminescence at room temperature, can be modeled using a three‐level system, and exhibit moderate bunching. Overall, the results provide important insights into understanding of defect formation and quantum emitter activation in two‐dimensional materials.
Elbadawi, C, Tran, TT, Kolíbal, M, Šikola, T, Scott, J, Cai, Q, Li, LH, Taniguchi, T, Watanabe, K, Toth, M, Aharonovich, I & Lobo, C 2016, 'Electron beam directed etching of hexagonal boron nitride.', Nanoscale, vol. 8, no. 36, pp. 16182-16186.View/Download from: UTS OPUS or Publisher's site
Hexagonal boron nitride (hBN) is a wide bandgap van der Waals material with unique optical properties that make it attractive for two dimensional (2D) photonic and optoelectronic devices. However, broad deployment and exploitation of hBN is limited by alack of suitable material and device processing and nano prototyping techniques. Here we present a high resolution, single step electron beam technique for chemical dry etching of hBN. Etching is achieved using H2O as a precursor gas, at both room temperature and elevated hBN temperatures. The technique enables damage-free, nano scale, iterative patterning of supported and suspended 2D hBN, thus opening the door to facile fabrication of hBN-based 2D heterostructures and devices.
Shanley, TW, Bonnie, F, Scott, J & Toth, M 2016, 'Role of gas molecule complexity in environmental electron microscopy and photoelectron yield spectroscopy.', ACS applied materials & interfaces, vol. 8, pp. 27305-27310.View/Download from: UTS OPUS or Publisher's site
Environmental scanning electron microscopy (ESEM) and environmental photoelectron yield spectroscopy (EPYS) enable electron imaging and spectroscopy of surfaces and interfaces in low vacuum, gaseous environments. The techniques are both appealing and limited by the range of gases that can be used to amplify electrons emitted from a sample, and used to form images/spectra. However, to date, only H2O and NH3 gases have been identified as highly favorable electron amplification media. Here we demonstrate that ethanol vapor (CH3CH2OH) is superior to both of these, and attribute its performance to molecular complexity and valence orbital structure. Our findings improve present understanding of what constitutes a favorable electron amplification gas, and will help expand the applicability and usefulness of the ESEM and EPYS techniques.
Scott, JA, Totonjian, D, Martin, AA, Toan, TT, Fang, J, Toth, M, McDonagh, AM, Aharonovich, I & Lobo, CJ 2016, 'Versatile method for template-free synthesis of single crystalline metal and metal alloy nanowires', NANOSCALE, vol. 8, no. 5, pp. 2804-2810.View/Download from: UTS OPUS or Publisher's site