Surfactant-free synthesis of GeO2 nanocrystals with controlled morphologies

Germanium dioxide has many applications in the optoelectronics sector and is the subject of substantial research interest. In this contribution we report the preparation of germanium dioxide nanoparticles (NPs) of varied sizes and morphologies using a facile sol-gel methodology that requires no addition of templating agents (e.g., surfactants). Morphological control is achieved by tailoring the reaction mixture water/ethanol ratio, ammonium hydroxide concentration, time, and temperature.