溶剂蒸汽退火辅助微距升华法制备C8-BTBT单晶

有机半导体单晶由于具有内部长程有序的分子排列结构、缺陷及晶界少等优点,表现出优异的光电性能,是实现有机半导体器件实用化的一种重要材料。目前,研究者们已经发展出多种可应用于有机单晶的生长方法,其中,微距升华法是一种可以在大气环境下采用蒸镀的方式制备有机微/纳单晶的方法。然而,当将这种方法应用于C8-BTBT时发现,由于分子的熔点较低,蒸镀得到的是分子直接从液态凝固为无定形/多晶的结构。在本工作中,通过使用溶剂蒸汽退火的方式对其进行后处理,成功地将这种无定形/多晶结构转化为分立的单晶。为了表征所得到的晶体形貌和结构,分别使用光学显微镜、X射线衍射和原子力显微镜等仪器对其进行了表征,发现所制备的晶体结构具备单晶的典型特征。

Preparation of C8-BTBT Single Crystals by Solvent Vapor Annealing Assisted Micro-Spacing Sublimation

Organic semiconductor single crystal has excellent device performance due to its long-range ordered molecular arrangement, few defects and grain boundaries. It is considered as a candidate to realize the practicability of organic semiconductor devices. At present, researchers have developed a variety of methods that can be applied in the growth of organic single crystals. Micro-spacing sublimation is a method to prepare organic micro/nano single crystals by sublimating organic semiconductor molecules onto substrates under ambient conditions. However, when C8-BTBT was treated by this method, amorphous/polycrystalline islands instead of single crystals were obtained due to the low melting point of C8-BTBT. In this work, these amorphous/polycrystalline islands are successfully transformed into discrete single crystals by solvent vapor annealing. The morphology and structure of the obtained crystals were characterized by optical microscope, X-ray diffraction characterization and atomic force microscope. The results show that the prepared crystals have typical characteristics of single crystals.