Nano/micro-structured germanium oxide (GeO2) was prepared using GeCl4 and KOH by a simple solution method in alkalic alcoholic solution. Different morphologies of GeO2 were obtained by changing the reaction conditions. The effects of the reaction time, the concentration of the reactants, the reaction temperature and the dispersant upon the morphology of the deposited GeO2 have been investigated. The products were detected by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM) and transmission electron microscope (TEM). Novel cross-like structures were obtained by using n-butylamine as the dispersant. The formation of the cross-like structures has been discussed and a solution-liquid-solid (SLS) mechanism was proposed.
WANG XiaoYan DUAN Lian DONG GuiFang WEI Peng WANG Wei WANG LiDuo QIU Yong
A series of tetracene-doped anthracene crystals with different doping concentrations(the highest mo-lar ratio 100:1) are grown from solution.Crystal structures and optical characteristics of the above mixed crystals are investigated at room temperature.By changing the doping concentrations,the fluorescence can be adjusted from blue-green to green and even to yellow-green.The emission spectra of anthracene/tetracene(An/Te) mixed crystals reveal the sensitized fluorescence of tetracene and the partial quenching of anthracene emission.The data of transient photoluminescence(PL) decays illus-trate that in An/Te mixed crystals,the decay of anthracene becomes faster,while the PL lifetime of tet-racene is longer than that of the tetracene single crystals.All above experimental results suggest that there is excitation energy transfer from anthracene to tetracene in the mixed crystals.
LI HuiPingDUAN LianZHANG DeQiangDONG GuiFangWANG LiDuoQIU Yong