New organometallic single-source precursors for CuGaS2 - polytypism in gallite nanocrystals obtained by thermolysis

作者：Kluge Oliver; Friedrich Dirk; Wagner Gerald; Krautscheid Harald^*

来源：Dalton Transactions, 2012, 41(28): 8635-8642.

DOI：10.1039/c2dt30904a

The complex [((Pr3PCu)-Pr-i)(2)(Me2Ga)(2)(SCH2CH2S)(2)] (4) was synthesized from trimethylgallium, [((Pr3PCu)-Pr-i)(4)(SCH2CH2S)(2)] (1) and ethanedithiol by elimination of methane. The related monomethyl compound [((Pr3PCu)-Pr-i)(2)(MeGaSPh)(2)(SCH2CH2S)(2)] (5) has been prepared from [((Pr3PCuSPh)-Pr-i)(3)] (2) and [(MeGaSCH2CH2S)(2)] (3) by a ligand exchange reaction in tetrahydrofuran solution. The molecular structures of 1 and 3-5 were determined by single crystal X-ray diffraction. Thermolysis of 4 and 5 results in the formation of the ternary semiconductor CuGaS2, gallite. The residue of 5 was characterized using X-ray powder diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy. The CuGaS2 crystals obtained are mainly hexagonal plates of around 200 to 300 nm diameter and 10 to 30 nm thickness, exhibiting an unusual metastable hexagonal crystal structure, related to wurtzite. Partially, the usual tetragonal chalcopyrite structure or its disordered cubic zinc-blende analogue is realized by stacking faults, resulting in an overall similarity to the zinc-blende-wurtzite polytypism in ZnS and related compounds.

• 出版日期2012