Accessing γ-Ga2S3 by solventless thermolysis of gallium xanthates: a low-temperature limit for crystalline products

Semiconductor Deposition via Laser Printing of a Bespoke Toner Containing Metal Xanthate Complexes

A methodology to use laser printing, a form of electrophotography, to print metal chalcogenide complexes on paper, is described. After fusing the toner to paper, a heating step is used to cause the printed metal xanthate complexes to thermolyze within the toner and form three target metal chalcogenides: CuS, SnS, and ZnS. To achieve this, we synthesize a poly(styrene-co-n-butyl acrylate) thermopolymer that emulates the thermal properties of a commercial toner and is also solution processable with the metal xanthate complexes used: [Zn(S2COEt)2], [Cu(S2COEt)·(PPh3)2], and [Sn(S2COEt)2]. We demonstrate through energy dispersive X-ray mapping that the toner is deposited following printing and that thermolysis of the metal xanthate complexes occurs in the fused toner, demonstrating the first example of laser printing of inorganic complexes and, in turn, semiconductors.

Structural Investigations of α-MnS Nanocrystals and Thin Films Synthesized from Manganese(II) Xanthates by Hot Injection, Solvent-Less Thermolysis, and Doctor Blade Routes

Manganese(II) xanthate complexes of the form [Mn(S2COR)2(TMEDA)], where TMEDA = tetramethylethylenediamine and R = methyl (1), ethyl (2), n-propyl (3), n-butyl (4), n-pentyl (5), n-hexyl (6), and n-octyl (7), have been synthesized and structures elucidated using single-crystal X-ray diffraction. Complexes 1-7 were used as molecular precursors to synthesize manganese sulfide (MnS). Olelyamine-capped nanocrystals have been produced via hot injection, while the doctor blading followed by thermolysis yielded thick films. Free-standing polycrystalline powders of MnS are produced by direct thermolysis of precursor powders. All thermolysis techniques produced cubic MnS, as confirmed by powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Raman spectroscopy. Magnetic measurements reveal that the α-MnS nanocrystals exhibit ferromagnetic behavior with a large coercive field strength (e.g., 0.723 kOe for 6.8 nm nanocrystals).

Direct synthesis of nanostructured silver antimony sulfide powders from metal xanthate precursors

Silver(I) ethylxanthate [AgS2COEt] (1) and antimony(III) ethylxanthate [Sb(S2COEt)3] (2) have been synthesised, characterised and used as precursors for the preparation of AgSbS2 powders and thin films using a solvent-free melt method and spin coating technique, respectively. The as-synthesized AgSbS2 powders were characterized by powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. The crystalline AgSbS2 powder was investigated using XRD, which shows that AgSbS2 has cuboargyrite as the dominant phase, which was also confirmed by Raman spectroscopy. SEM was also used to study the morphology of the resulting material which is potentially nanostructured. EDX spectra gives a clear indication of the presence of silver (Ag), antimony (Sb) and sulfur (S) in material, suggesting that decomposition is clean and produces high quality AgSbS2 crystalline powder, which is consistent with the XRD and Raman data. Electronic properties of AgSbS2 thin films deposited by spin coating show a p-type conductivity with measured carrier mobility of 81 cm2 V-1 s-1 and carrier concentration of 1.9 × 1015 cm-3. The findings of this study reveal a new bottom-up route to these compounds, which have potential application as absorber layers in solar cells.

Synthesis and characterization of zinc di(O-2,2-dimethylpentan-3-yl dithiocarbonates) bearing pyridine or tetramethylethylenediamine coligands and investigation of their thermal conversion mechanisms towards nanocrystalline zinc sulfide

Metal xanthates are versatile single source precursors for the preparation of various metal sulfides. In this study, we present the synthesis of the two novel zinc xanthate complexes bis(O-2,2-dimethylpentan-3-yl-dithiocarbonato)(N,N,N',N'-tetramethylethylenediamine)zinc(ii) and bis(O-2,2-dimethylpentan-3-yl-dithiocarbonato)(pyridine)zinc(ii). A thorough investigation of these compounds revealed distinct differences in their structural and thermal properties. While in the complex containing the chelating tetramethylethylenediamine, the xanthate groups coordinate in a monodentate way, they are bidentally coordinated to the zinc atom in the pyridine containing complex. Both compounds show a two-step thermal decomposition with an onset temperature of 151 °C and 156 °C for the tetramethylethylenediamine and pyridine containing complex, respectively. Moreover, different mechanisms are revealed for the two phases of the decomposition based on high resolution mass spectrometry investigations. By the thermal conversion process nanocrystalline zinc sulfide is produced and the coligand significantly influences its primary crystallite size, which is 4.4 nm using the tetramethylethylenediamine and 11.4 nm using the pyridine containing complex for samples prepared at a temperature of 400 °C.