在分子束外延(MBE)系统中,利用物理气相沉积(PVD)的方法在阳极氧化铝(AAO)模板上制备了有机染料分子苝四甲酸二酐(PTCDA)的不同纳米结构;并使用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)以及选区电子衍射(SAED)技术进行了系统的研究.结果发现,当衬底温度(T_s)为330℃时得到的是纳米丝、针、带以及棒;T_s为280℃,230℃,180℃时得到的主要是纳米棒,并且纳米棒的长度随T_s的降低而变短;T_s为50℃时只能得到连续的PTCDA薄膜.HRTEM以及SAED结果证实了纳米针与棒为单晶.依据SEM结果,提出纳米结构的生成主要受T_s以及衬底表面曲率的影响.
Different types of nanostructures of an organic dye compound,perylene-3,4,9,10-tetracarboxylic-dianhydride(PTCDA),are prepared on anodic alumina oxide(AAO) at different values of substrate temperature(T_s) by a facile physical vapor deposition(PVD) method in a molecular beam epitaxy(MBE) system.Scanning electron microscopy(SEM),transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM) and selected area electron diffraction(SAED) techniques are applied to the systematical characterization of the nanostructures.It is found that the PTCDA nanofibers,nanoneedles,nanobelts,and nanorods are produced at 330℃T_s;Only nanorods are formed at 280℃,230℃,and 180℃,and their lengths become short as T_s decreases; the continuous films are obtained on 50℃AAOs substrates.HRTEM and SAED results show that the nanoneedle and nanorods are of single crystal.According to SEM results,the formation of PTCDA nanostructures should be mainly affected by surface curvature and