Novel solution synthesis of the overlooked cubic phase Cu2GeTe3 nanocrystals for optoelectronic devices.

Herein, for the first time, we present a novel solution method for controllable synthesis of the overlooked cubic phase Cu2GeTe3 nanocrystals. The resulting Cu2GeTe3 nanocrystals are of high quality with monodispersed size and uniform shape. Optical characterization demonstrates that Cu2GeTe3 nanocrystals have a broad absorption in the visible to near-infrared region. Furthermore, an optoelectronic device based on Cu2GeTe3 nanocrystals exhibits excellent stability, reproducibility and responsivity. The novel synthetic route presented here not only can open a new avenue for fabricating Cu2GeTe3 nanocrystals, especially at the nanoscale, but also may further expand their applications.