From kitchen to lab: fabricating Ge nanoparticles using a household blender

In this work, a simple and accessible method for producing colloidal Ge nanoparticles (GeNPs) in ethanol medium using an ordinary kitchen blender is demonstrated. The obtained GeNPs exhibit a polydisperse size distribution in the range of 20-200 nm with characteristic maxima near 30 nm and form stable colloidal solutions with Z-potential values of around -20 ± 8 mV. Morphological and spectroscopic studies confirmed the formation of partially oxidized crystalline GeNPs with pronounced nanoscale effects. The UV-Vis absorption spectra of the GeNPs demonstrate a broad asymmetric peak with a maximum near 4.4 eV. Spectral deconvolution revealed two overlapping components at 4.25 eV and 4.5 eV, which are associated with the E₂ interband transitions in crystalline Ge and their modification in nanoparticles under the influence of quantum confinement effects and surface oxidation. The PL/PLE spectra reveal a dominant blue-green photoluminescence in the 430-520 nm range under UV excitation (250-395 nm), which is attributed to a combination of quantum confinement in the GeNPs and radiative recombination through defect states and oxygen-containing centers at the Ge/GeO _x interface.