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Abstract Germanium-based oxides such as rutile GeO 2 are garnering attention owing to their wide band gaps and the prospects of ambipolar doping for application in high-power devices. Here, we present the use of germanium tetraisopropoxide (GTIP), a metal-organic chemical precursor, as a source of germanium for the demonstration of hybrid molecular beam epitaxy for germanium-containing compounds. We use Sn 1- x Ge x O 2 and SrSn 1- x Ge x O 3 as model systems to demonstrate our synthesis method. A combination of high-resolution X-ray diffraction, scanning transmission electron microscopy, and X-ray photoelectron spectroscopy confirms the successful growth of epitaxial rutile Sn 1- x Ge x O 2 on TiO 2 (001) substrates up to x = 0.54 and coherent perovskite SrSn 1- x Ge x O 3 on GdScO 3 (110) substrates up to x = 0.16. Characterization and first-principles calculations corroborate that germanium occupies the tin site, as opposed to the strontium site. These findings confirm the viability of the GTIP precursor for the growth of germanium-containing oxides by hybrid molecular beam epitaxy, thus providing a promising route to high-quality perovskite germanate films.
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This content will become publicly available on May 1, 2027
Hydrothermal route to semiconductor Cu2GeS3 nanoparticles with monoclinic structure
Copper germanium sulfide-Cu2GeS3, is a ternary chalcogenide semiconductor that has attracted significant attention due to its tunable band gap, non-toxic and Earth-abundant elements in its composition, and versatile synthetic routes. However, the poor aqueous solubility of commonly used germanium precursors (GeO2, GeCl4) has hindered the development of green synthesis methods for Cu2GeS3. To overcome this challenge, we employed a diaquabis (glycolato-O,O′′) germanium(IV) (Ge-GA) prepared in house, as a water-soluble germanium precursor to produce Cu2GeS3 nanoparticles through a simple, one-step hydrothermal synthesis method. In addition to the Ge-GA, the hydrothermal synthesis of Cu2GeS3, utilizes inexpensive precursors: copper chloride dihydrate and thioacetamide, and leads to nanoparticles crystallizing in a monoclinic structure. The crystallographic and morphological properties were confirmed by X-ray diffraction with Rietveld refinement, Raman spectroscopy, high-resolution transmission electron microscopy (TEM) equipped with electron dispersive X-Ray spectroscopy (EDS), and scanning electron microscopy (SEM) with EDS. Optical characterization revealed a band gap of ~ 1.69 eV, while first-principles calculations were used to analyze the band structure and density of states. This work demonstrates the first aqueous synthesis approach of Cu2GeS3 nanoparticles, a facile method that could be extrapolated to other Ge-containing compounds. As Cu2GeS3 is a semiconductor, this synthesis route opens avenue for its facile translation to optoelectronic, thermoelectric and photovoltaic applications.
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- PAR ID:
- 10709113
- Publisher / Repository:
- Journal of Materials Science, Springer Nature
- Date Published:
- Journal Name:
- Journal of Materials Science
- Volume:
- 61
- Issue:
- 19
- ISSN:
- 0022-2461
- Page Range / eLocation ID:
- 13390 to 13402
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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