Synthesis of submicron-sized rods and trees of Cu2O by radio-frequency magnetron sputtering

• Cu2O submicron-sized rods and trees were synthesized by RF magnetron sputtering.
• Effects of substrate temperature and sputtering time on the formation of Cu2O submicron-rods were investigated.
• The morphologies of Cu2O were tailored by Ar/O2 ratios during the sputtering.
• A formation model was proposed and illustrated in detail.

Typical sputtering conditions based on substrate temperature, sputtering time and oxygen partial pressure to grow thin film, submicron-sized rods and trees of Cu2O on glass substrates from metallic Cu targets were investigated. The submicron-rods with diameters of 100–700 nm and lengths of 2–8 μm were synthesized. The abundance of Cu species, which is modulated by the Ar/O2 ratio during the sputtering process affects directly to the growths of the Cu2O branches on the bodies of the submicron-rods. Transmission electron microscopy and elemental mapping reveal that metallic Cu is existed on the heads of the Cu2O rods. Finally, the formation model of the submicron-sized rods and trees of Cu2O is discussed.