Wurtzite Cu₂GeS₃ Nanocrystals: Phase‐ and Shape‐Controlled Colloidal Synthesis

Abstract

The first colloidal synthesis of Cu2 GeS3 (CGS) nanocrystals with a thermodynamically metastable wurtzite crystal phase is reported. As a benefit of the sulfur precursors used in the synthesis, the shape of the as-synthesized wurtzite CGS nanocrystals can be controlled in the form of spherical nanoparticles, nanorectangles, and hollow nanorectangles. A detailed investigation into the effects of reaction conditions necessary to obtain phase-pure wurtzite CGS nanocrystals is presented. The choice of sulfur precursor and precursor injection temperature play a significant role in determining the crystal phase of the CGS nanocrystals. The band gap of the new wurtzite phase CGS was measured to be 1.76 eV and the CGS nanocrystals exhibited a good electrochemical photoresponse, which was indicative of their potential application as an active layer in the field of solar cells.

Facile Synthesis of Cu2GeS3 and Cu2MGeS4 (M = Zn, Mn, Fe, Co, and Ni) Hollow Nanoparticles, Based on the Nanoscale Kirkendall Effect

“…The Ge 3d peak is a single peak at 30.8 eV, indicating the typical of tetravalent GeS 2 and excluding the presence of GeO 2 . Overall, no secondary phase in the Cu 2 GeS 3 hollow NPs can be detected. , …”

“…To exclude other growth mechanisms, Cu 7 S 4 NPs are synthesized by heating CuCl and TGA in OLA. If OLA etching or bubble template mechanism is dominant, the as-prepared Cu 7 S 4 NPs should be hollow structures . However, the obtained Cu 7 S 4 NPs are solid with a monoclinic crystal phase (JCPDS File No.…”

Compound Copper Chalcogenide Nanocrystals

“…To the best of our knowledge, there is only one report of Cu 2 GeS 3 NCs with the metastable wurtzite phase . The synthesis involved the injection of a thiol mixture (tDDT/DDT) at 200°C into a solution of CuCl, GeI 4 , and OLA, followed by heating at 300 °C for 2 h. By adjusting the thiol ratio used in the synthesis, the NC shape was controlled in the form of spherical particles, nanorectangles, and hollow nanorectangles.…”

Tailoring Porosity in Copper-Based Multinary Sulfide Nanostructures for Energy, Biomedical, Catalytic, and Sensing Applications

“…It was noted that, when sulfur powder was used instead of thiourea as the sulfur source, no gas bubbles were released, and thus, the interiors of the final structures in this case are nonhollow. The bubble-templating approach has also been reported by Ramasamy et al in the formation of hollow Cu 2 GeS 3 nanostructures . In their work, the hot-injection technique was employed where the thiol precursors are rapidly injected into a hot oleylamine dispersion of the copper and germanium precursors.…”

“…The bubble-templating approach has also been reported by Ramasamy et al in the formation of hollow Cu 2 GeS 3 nanostructures. 105 In their work, the hot-injection technique was employed where the thiol precursors are rapidly injected into a hot oleylamine dispersion of the copper and germanium precursors. The decomposition of thiols spawned the H 2 S gas bubbles that served as aggregation centers for the eventual formation of Cu 2 GeS 3 nanocrystals having hollow interiors.…”