Synthesis, Structure and Application of Intramolecularly-Coordinated Gallium Chalcogenides: Suitable Single-Source precursors for Gax Sey Materials.

Abstract

Studies have been focused on the synthesis of N→Ga-coordinated organogallium selenides and tellurides [L1 Ga(μ-Se)]2 (1), [L2 Ga(μ-Se)]2 (2) and [L1 Ga(μ-Te)]2 (3), respectively, containing either N,C,N- or C,N-chelating ligands L1, 2 (L1 is {2,6-(Me2 NCH2 )2 C6 H3 }- and L2 is {2-(Et2 NCH2 )-4,6-tBu2 -C6 H2 }- ) having Ga/E (E=Se or Te) atoms in 1/1 ratio. To change the Ga/E ratio, an unusual N→Ga-coordinated organogallium tetraselenide L1 Ga(κ2 -Se4 ) (4) was prepared. An unprecedented complex (L1 Ga)2 (μ-Te2 )(μ-Te) (5), as the result of the non-stability of 3, was also isolated. Compound 2 is a suitable single-source precursor for the preparation of amorphous GaSe thin films by the spin coating. Moreover, simple heating of an octadecylamine solution of 2 provided, after work up, monoclinic Ga2 Se3 crystals with different crystallinity according to conditions used. Therefore, compound 2 may be also used as a source of Ga2 Se3 in the low-temperature doping process of Bi2 Se3 .