Synthesis and growth mechanism of dendritic Cu2−xSe microstructures

Dendritic crystalline copper selenides Cu2-xSe microstructures with various dimensions have been fabricated in large scale through thermal treatment of CuSe powder in argon flow, without any catalyst. The CuSe powder grains were used as both reagents and substrates for the growth of the Cu2-xSe dendrites. The synthesized microstructures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, selected area diffraction pattern and Raman spectroscopy. Each individual dendrite was mainly composed of a long central trunk with secondary lateral branches. The length of the main trunk was in the range 10-30 mu m, the width of the secondary branch lay in the range 1-5 mu m. The trunk was about 1-2 mu m in diameter while the lateral branches were about 0.4-0.8 mu m in diameter. The lateral branches grew in parallel and kept about 60 degrees with respect to the central trunk. A possible growth mechanism has been also proposed to account the growth of these Cu2-xSe dendritic microstructures.