New Routes to II-VI Materials
Abstract
Zinc and cadmium dithiocarbamates were synthesized and used as single
molecule precursors for the deposition of zinc or cadmium chalcogenides. The
precursors were based on trimethylpropylenediamine including bis(trimethylpropylenediaminedithiocarbamato)
zinc(lll)\cadmium(II) (3), (4) and methyl(trimethylpropylenediaminedithiocarbamato)
zinc(III)\cadmium(II) (5), (6). These compounds have been
chracterized by I. R, NMR ('H, 13Ca nd 11C3 d) and mass spectrometry. The c,ý sU*7
structures of bis(U-imethylpropylenediminedthiocarbamato)zinc(III) (3) and methyl-
(ft-imethylpropylenediaminedithiocarbamato)cadmium (H) (6) have been determined, both
compounds were polymeric. Thin films of zinc or cadmium sulfide by MOCVD method
have been grown from (3), (4), (5) and (6). The cadmium compounds gave good films
on both glass and GaAs substrates, but the films grown from corresponding zinc
compounds were of poorer quality. Some t-butyl- and neopentyl(di-alkylamido)zinc
compounds have been synthesized and characterized.
Thin films of CdS, ZnS, CdZni-. S, and ZnO were grown by chemical bath
deposition method. US films were deposited by using cadmium/ethylenediamine-
/thiourea system whereas ZnS films were grown from zinc/ammonia/hydrazine/thiourea
system. Films of ternary Cd,, Znl-,, S have been obtained by the addition of cadmium to
the ZnS system. Calculation were carried out for the speciation of the solution for which
US was deposited. Films of ZnO were deposited from solution containing
zinc/ethylenediamine in presence of NaOH. The various parameters controlling the film
quality, growth rates, morphology and crystallinity were investigated. The films
deposited were characterized by several methods including scanning electron
microscopy, tramission electron microscopy, X-ray powder diffraction, reflection high
energy electron diffraction and the electronic spectroscopy.
Authors
Saeed, TahirCollections
- Theses [3706]