抗菌医药左氧氟沙星在有机电致发光二极管中的应用

摘要

Levofloxacin (LOFX) is a wel-known and inexpensive antimicrobial drug that can be easily synthesized and purified. We report the first application of LOFX to an organic light emitting diode (OLED). Its thermal and photophysical properties were thoroughly investigated using thermogravimetric analysis (TGA), UV-Vis absorption spectra, emission spectra, and cyclic voltammetry. LOFX has HOMO and LUMO energies of-6.2 and-3.2 eV, respectively, and high molecule decomposition temperature (Td) of 327 °C. An OLED with a LOFX emitter shows electroluminescence (EL) at 452 nm and maximum luminance of 2315 cd∙A-1, which can be used in a white OLED. To investigate the electron transporting ability of LOFX, an electron-carrier only OLED was made. In addition, a green OLED based on Ir(ppy)3 (fac-tris(2-phenylpyridine)iridium) with electron transporting layer of LOFX was made, comparing with that with electron transporting layer of tris(8-hydroxyquinoline) aluminum (Alq3). The former exhibited higher device efficiencies than that of the latter. The results show that LOFX has a higher electron transport ability than Alq3.%左氧氟沙星(LOFX)是一种知名的抗菌药物,它的价格非常便宜,且有成熟的合成和纯化技术.本文中首次将LOFX作为一种蓝光发光材料和电子传输材料应用于有机电致发光器件(OLED)中.通过热重分析、UV-Vis吸收光谱、发射光谱以及循环伏安曲线详细地表征了LOFX的热学及光物理特性. LOFX有高的分解温度,为327°C；HOMO、LUMO能级分别为-6.2和-3.2 eV,光学带隙为3.0 eV.以LOFX作为客体材料,掺杂在主体材料4,4'-二(9-咔唑)联苯(CBP)中制备了蓝光OLED,该器件的电致发光(EL)发射峰位于452 nm,最大亮度为2315 cd∙m-2.进一步,选择8-羟基喹啉铝(Alq3)作为参考材料,分别以LOFX和Alq3作为电子传输材料制备了结构相同的单载流子器件和绿色磷光OLED.在相同的电压下,以LOFX作为电子传输材料的单载流子器件的电流密度比以Alq3作为电子传输材料的单载流子器件更高.同时,以LOFX作为电子传输材料的绿色磷光OLED获得更高的器件效率.从这些EL性能可以看出, LOFX同时也是一很好的电子传输材料.