Synthesis of Germanium Dioxide Microclusters on Silicon Substrate in Non-aqueous Solution by Electrochemical Deposition

Abstract

We report the formation of crystalline germanium dioxide (GeO₂) microclusters on n-Si (100) electrodeposited in non-aqueous electrolyte (a mixture of 5 vol.% germanium tetrachloride (GeCl₄) and dipropylene glycol (C₆H₁₄O₃) ) at current density of 20 mA/cm² for 200 sec. Pt, C and Ge are used as an anode while Si acts as a cathode. Field- emission scanning electron microscopy (FESEM) images show that the deposited GeO₂ microclusters are having rounded-mushroom-shaped particles with the smallest size of 660 nm. Energy dispersive x-ray (EDX) spectra reveal that the particles are only composed of Ge and O elements. Raman spectra confirm the formation of crystalline GeO₂ with trigonal bonding structures in all samples. The photoluminescence (PL) spectra show two significant emission peaks in visible range at 2.27 eV and 2.96 eV, which seems to be attributed by GeO₂ and Si defects. C₆H₁₄O₃ seems to contribute to the formation of GeO₂ due to its hygroscopic nature. Such microcluster structures shall provide some potential applications for electronic and optical devices on Si platform.