The use of alternative nitrogen sources for growing GaN materials by organometallic vapor phase epitaxy (OMVPE) is being continuously investigated in the hope of achieving device-quality films under moderate conditions, in comparison to conventional methods. Employing the single molecule precursor (N 3 ) 2 Ga[(CH 2 ) 3 NMe 2 ], and using a cold-wall CVD reactor, epitaxial films of GaN, transparent in appearance and stoichiometric in composition, were deposited on c-plane sapphire, in the absence of ammonia, above 1073 K, under low pressures (between 0.080 and 100.0 mbar). Dense, amorphous, and very smooth films were grown at temperatures as low as 773 K. The influence of substrate temperature, reactor pressure, and the effect of small quantities of additional ammonia, on the growth rate and the film properties, were studied in some detail. The films were characterized by high-resolution X-ray diffraction (XRD) (e.g., full width at half maximum (FWHM) of the 0002 GaN rocking curve of 130 arcsec), X-ray reflectometry, scanning electron microscopy (SEM), atomic force microscopy (AFM) (root mean square roughness of 1.9 nm), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), Rutherford backscattering (RBS) (Ga/N = 1:1 ± 0.05), and photoluminescence (PL) measurements (band edge luminescence at 3.45 eV and FWHM of 0.22 eV at 300 K).

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Die übergangsmetallsubsituierten Gallane [(CO)5MnGaEt2(NC7H13)] (1), [(PMe3)(CO)3CoGaCl2 · (NMe3)] (2), [(CO)4CoGaEt2(NC7H13)] (3) und [(CO)4CoGaCl3]K (4) wurden durch Reaktion der Carbonylmetallate [(CO)nM] (Na/K) mit den Galliumchloriden ClGaEt2(NC7H13), Cl3Ga(NMe3) bzw. GaCl3 erhalten. Die Einkristallstrukturbestimmungen ergaben für 1: Raumgruppe P21/c (I.T.‐Nr.: 14); Z = 4; a = 1425,4(2) pm, b = 1007,4(1) pm, c = 1429,9(3) pm; β = 113,92(1)°; 2: Raumgruppe P21/m (I.T.‐Nr.: 11); Z = 2; a = 746,1(1) pm, b = 1131,2(1) pm, c = 1061,5(1) pm; β = 101,87(1)°; 3: Raumgruppe P21/c (I.T.‐Nr.: 14); Z = 8; a = 1405,9(2) pm, b = 1786.2(2) pm, c = 1430,9(2) pm; β = 91,47(1)°; 4: Raumgruppe P21/c; Z = 4; a = 1185,7(1) pm, b = 895,4(1) pm, c = 1144,7(3) pm; β = 106,47(2)°. Anhand der Modellverbindungen [{L′(CO)3Co}GaX2L] (L′ = CO, PH3; L = NH3, X = H, Cl) wurden die polaren σ(Co–Ga)‐Bindungen und die Substituenteneffekte auf die Bindungslänge auf der Basis quantenchemischer Dichtefunktionalrechnungen (DFT) charakterisiert.

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