Design and growth of dendritic Cu2 xSe and bunchy CuSe hierarchical crystalline aggregations†

Dendritic nanocrystals of copper selenide were fabricated in situ for the first time by using alcohol as the solvent. Cu2 xSe films composed of hierarchically ordered dendritic nanostructures were prepared on Cu substrates at a rather moderate temperature of 190–200 C for just 1–3 h, while bunchy CuSe nanostructures could be further constructed above the Cu2 xSe dendrites by prolonging the reaction time of solvothermal growth with ethanol as the solvent. The resulting Cu2 xSe nanodendrites display highly symmetric corolitic morphology while the bunchy CuSe aggregations show particular nanostructures with a pronounced trunk and actinomorphic multi-branches. It is also found that the dendritic structures of crystalline Cu2 xSe could never be obtained when the reaction temperature is less than 190 C, while the temperature needed is 160 C for Ag2Se nanodendrites and higher than 220 C for CdSe nanodendrites. These copper selenide nanostructures with hierarchically ordered 3-dimensional (3D) framework exhibited good absorbance and photoluminescence (PL) property and could bear potential applications in solar cell devices in the future.