Single Source Precursors for the Growth of Metal-Chalcogenide Thin Films

Abstract

We have recently reported the growth of ZnTe and CdTe thin films from the novel volatile single-source precursors Zn(sitel)2 and Cd(sitel)2 [sitel = TeSi(TeSi(siMe3)3]. In an effort to understand the role played by the bulky substituents, we have prepared a number of related compounds and have investigated their potential for the growth of II-VI materials. We now describe the synthesis and characterization of M[EX(SiMe3)3]2 (M = Zn, Cd, Hg for E = Te, X = C; M = Zn for E = Se, X = C, Si) and their use as precursors molecules for the growth of ZnSe, ZnTe, CdTe and HgTe. The thin films were characterized by Rutherford Back scattering spectrometry (RBS) and X-ray diffraction. Pyrolysis reaction conditions for the alkyl and silyl chalcogenolates are also compared.

A solid-state NMR investigation of single-source precursors for group 12 metal selenides; M[N(iPr2PSe)2]2(M = Zn, Cd, Hg)

“…108,110 Solidstate 199 Hg NMR spectra were referenced to dimethyl mercury by setting the 199 Hg NMR peak of solid (NEt 4 )Na[Hg(CN) 4 ] to −434 ppm. 111 Solid-state 31 P NMR experiments were performed at frequencies of 81.0, 121.6 and 202.5 MHz at spinning frequencies ranging from 1.0 to 2.2 kHz. A total of between 64 and 512 scans were acquired per spectrum.…”

“…2. This procedure yields the principal components of the phosphorus chemical shift tensors as well as an estimate of the indirect spin-spin coupling constant, 1 J( 77 Se, 31 P) iso , from the satellite peaks visible within the 31 complexes respectively. The average of the four experimental and calculated values of d iso for the single-source precursors investigated shows a small yet consistent decrease as one progresses from the Zn to the Cd to the Hg complex.…”

“…52 Characterization of dichalcogenoimidodiphosphinato complexes has to date been performed primarily by X-ray crystallography, as well as infrared and solution NMR spectroscopy. 22,45,46,48,59,62-64,67,71,94,97-105 Diselenoimidodiphosphinate ligands possess numerous favorable NMR spin-1/2 nuclei, specifically 1 H (99.99% N.A., N = 100 MHz), 13 C (1.07% N.A., N = 25.145 MHz), 31 P (100% N.A., N = 40.481 MHz), and 77 Se (7.63% N.A., N = 19.071 MHz), but characterization has typically been limited to 1 H and 31 P solution NMR. Solid-state NMR, being potentially more informative than solution NMR spectroscopy, would appear to be an appropriate technique for characterizing the detailed molecular environment of dichalcogenoimidodiphosphinate ligands and their complexes; however, there have been no reports of such investigations in the literature to our knowledge.…”

MOCVD of Chalcogenides, Pnictides, and Heterometallic Compounds from Single-Source Molecule Precursors

“…They form dimers in the solid state, with two bridging and two terminal Q atoms. [50,51] Most of them could be successfully used for the deposition of selenides and tellurides in rather mild conditions. [51,52] In a preliminary study, thin films of ZnTe and CdTe were grown from Zn(sitel) 2 and Cd(sitel) 2 (m.p.…”

“…[51] The decomposition pathway for the alkyl-chalcogenolates proved to be less straightforward than that for the silyl-chalcogenolates.…”