Chinh Q. Nguyen

The CVD of silver selenide films from dichalcogenophosphinato and imidodichalcogenodiphosphinatosilver(I) single-source precursors

A series of dichalcogenophosphinato [Ag(Se2PiPr2)] (1), [Ag(SSePiPr2)]4 (2), and imidodichalcogenodiphosphinatosilver(I) [Ag{iPr2P(S)NP(Se)iPr2}]3 (3) [Ag{(SePiPr2)2N}]3 (4) complexes were synthesised; (2) and (3) were characterised by X-ray single crystallography. Complex (2) has a tetrahedral arrangement of four silver atoms with four thioselenophosphinate ligands along the edges, (3) is a trimer. The compounds (1), (2), (3) and (4) were employed as single-source precursors (SSPs) in aerosol assisted chemical vapour deposition (AACVD) and low pressure (LP) CVD. All precursors gave silver selenide (Ag2Se) films by AACVD, whereas only (3) and (4) deposited Ag2Se films by LPCVD. The as-obtained films were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) methods.

Synthesis of the nickel selenophosphinates [Ni(Se2PR2)2] (R = iPr, tBu and Ph) and their use as single source precursors for the deposition of nickel phosphide or nickel selenide nanoparticles

Nickel phosphide (Ni(2)P and Ni(12)P(5)) or nickel selenide (NiSe) nanoparticles were prepared from the single molecule precursor, dialkyldiselenophosphinato nickel(II), [Ni(Se(2)PR(2))(2)] (R = (i)Pr, (t)Bu and Ph) by thermolysis in trioctylphosphine oxide (TOPO) or hexadecylamine (HDA). The chemical composition of these nanoparticles depends on the precursors, capping agents, and reaction temperature.

Ligand influence on the formation of P/Se semiconductor materials from metal–organic complexes

The complexes [Ni{(SeP(i)Pr(2))(2)N}(2)] (2), [Ni(Se(2)P(i)Pr(2))(2)] (), and [Co(Se(2)P(i)Pr(2))(2)] (4) were synthesised and the X-ray single crystal structures of (1) and (2) were determined. Thin films of nickel selenide, cobalt selenide and cobalt phosphide have been deposited by the chemical vapour deposition method using imidodiselenophosphinato-nickel(ii) (1), -cobalt(ii) [Co{(SeP(i)Pr(2))(2)N}(2)] (3), diselenophosphinato-nickel(ii) (2), -cobalt(ii) (4) and diselenocarbamato-nickel(ii) [Ni(Se(2)CNEt(2))(2)] (5), and -cobalt(iii) [Co(Se(2)CNEt(2))(3)] (6) precursors.

The N-alkyldithiocarbamato complexes [M(S2CNHR)2] (M = Cd(II) Zn(II); R = C2H5, C4H9, C6H13, C12H25); their synthesis, thermal decomposition and use to prepare of nanoparticles and nanorods of CdS

A series of N-alkyldithiocarbamato complexes [M(S2CNHR)2] (M=Cd(II), Zn(II); R=C2H5, C4H9, C6H13, C12H25) have been synthesised and characterized. The decomposition of these complexes to sulfates has been investigated, and a mechanism proposed. The structures of [Zn(S2CNHHex)2], [Cd(SO4)2(NC5H5)4)]n and [Cd(SO4)2(NC5H5)2(H2O)2)]n have been determined by X-ray single crystal method. The cadmium complex [Cd(S2CNHC12H25)2] and zinc complex [Zn(S2CNHC6H13)2] were used as single-source precursors to synthesize CdS and ZnS nanoparticles, respectively. The synthesis of CdS nanoparticles was carried under various thermolysis conditions and changes in the shape of derived nanoparticles were studied by transmission electron microscope (TEM).

Metal complexes of selenophosphinates from reactions with (R2PSe)2Se: [M(R2PSe2)n] (M = ZnII, CdII, PbII, InIII, GaIII, CuI, BiIII, NiII; R = iPr, Ph) and [MoV2O2Se2(Se2PiPr2)2]

The reactions of bis(dialkylselenophosphinyl)selenide with a series of metals have been investigated: synthesis of several metal selenophosphinate complexes and their structures are reported.

Supercritical Chemical Fluid Deposition of High Quality Compound Semiconductors

The main advantage of deposition from supercritical fluids over conventional CVD is the ability to fill high aspect ratio templates. Deposition of metals, indirect semiconductors and insulators into templates with dimensions down to 3 nm has been demonstrated by others, with no apparent pore blocking. In this paper we present a demonstration that it is also possible to deposit high quality, luminescent compound semiconductor films from supercritical CO2 or CO2/hexane mixtures. Depositions of CdS and III-V materials such as InP have been achieved through careful optimisation of precursor chemistry, reactor geometry and deposition conditions, supported by detailed measurements of the semiconductor film properties

Optical Characterisation of CdSe Nanocrystal Quantum Dots Grown from New Single Source Precursors

CdSe nanocrystal quantum dots have been fabricated by decomposing three novel diselonophosphinate single source precursors. The absorption spectrum, and photoluminescence spectrum and lifetime have been measured in each case. The photoluminescence spectra reveal the usual peak associated with band-edge recombination and a second strong peak at shorter wavelengths, attributed to recombination from higher lying energy levels. The photoluminescence lifetime associated with these short wavelength peaks is of the order of 1 ns and comparable to the lifetime of band-edge emission.