溶液相大尺寸有机薄晶体的生长及其场效应晶体管研究

The growth of large-size organic thin crystals by solution process for the application on organic field effect transistors

利用改进的两溶剂混合法生长出大尺寸6，13一双（三异丙基甲硅烷基乙炔基）并五苯（TIPS-PEN）薄晶体。晶体尺寸可达几毫米，厚度范围为90～700nm。用偏光显微镜确定了其单结晶性。通过对比实验发现，随着溶液浓度的升高，有机薄晶体尺寸增大，厚度增加。用X射线衍射和选区电子衍射对TIPS-PEN薄晶体进行表征，结果显示薄晶体具有非常高的有序结构。基于薄晶体的场效应晶体管（FET）具有高的空穴迁移率，达0．39cm2／v·S，较旋涂制备的薄膜晶体管高两个量级，并且随着薄晶体厚度的降低载流子迁移率增加。

The authors adopted the improved co-solvent method to prepare the large-size thin crystals of semi- conducting 6,13-bis（triisopropylsilylethynyl）pentacene （TIPS-PEN）. The thin crystals show the lateral size as large as a few millimeters and the thickness in the range from 90 to 700 nm. Polarized optical microscopy con- firms their single crystalline nature. The size and thickness of the thin crystals increase with the increasing of the solution concentration. X-ray diffraction and SEAD analysis reveals that the crystals exhibit high molecular orientation and high structural ordering. The field effect transistors （FET） based on the TIPS-PEN thin crys- tals exhibit a high hole mobility of 0.39 cm2/V .s, two orders of magnitude larger than those from the cast thin films. The hole mobility was found to increase with decreasing the thickness of the crystals.