Desai Netaji K, Kolekar Govind B, Patil Shivajirao R
Post Graduate Department of Chemistry, Balwant College, Vita, 415311, India.
Fluorescence Spectroscopy, Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur, 416 004, India.
J Fluoresc. 2020 Sep;30(5):999-1005. doi: 10.1007/s10895-020-02566-3. Epub 2020 Jun 29.
Thin films of p-terphenyl luminophors doped by varying amounts of anthracene were prepared by using spin coating technique. The morphological, structural, and photophysical investigation of thin films of p-terphenyl as a function of anthracene concentration is studied by using scanning electron microscopy (SEM), X-ray diffraction (XRD), fluorescence spectroscopy and fluorescence microscopy. The results of XRD and SEM studies indicated that the doped p-terphenyl thin film is homogeneous as compared with a bare p-terphenyl thin film. The fluorescence spectroscopy results indicate complete quenching of p-terphenyl fluorescence and simultaneous sensitization of blue anthracene like emission towards the red side of the spectrum with maximum intensity at 410 nm. The blue intense emission of anthracene seen in fluorescence microscopy images is in agreement with observed fluorescence spectral results. A suitable mechanism of excitation energy transfer (EET) from p-terphenyl to anthracene molecules is proposed and discussed on the basis of energy level diagram. The efficient EET is believed to occur by the orientation of phenyl rings of p-terphenyl in excited state. As the concentration of doped anthracene increases, the fluorescence intensity of doped p-terphenyl and Full Width at Half Maximum (FWHM) found to be increased. The p-terphenyl film containing 0.65 moles of anthracene is of FWHM as low as 28.51 nm. Such narrow band blue emitting doped luminophors are of demand in light emitting diodes (OLED) and scintillation applications.
采用旋涂技术制备了掺杂不同量蒽的对三联苯发光体薄膜。通过扫描电子显微镜（SEM）、X射线衍射（XRD）、荧光光谱和荧光显微镜研究了对三联苯薄膜的形态、结构和光物理性质随蒽浓度的变化。XRD和SEM研究结果表明，与未掺杂的对三联苯薄膜相比，掺杂的对三联苯薄膜是均匀的。荧光光谱结果表明，对三联苯荧光完全猝灭，同时蓝色蒽类发射向光谱红端敏化，在410nm处强度最大。荧光显微镜图像中观察到的蒽的蓝色强发射与荧光光谱结果一致。基于能级图提出并讨论了从对三联苯到蒽分子的合适的激发能量转移（EET）机制。认为有效的EET是由激发态下对三联苯苯环的取向引起的。随着掺杂蒽浓度的增加，掺杂对三联苯的荧光强度和半高宽（FWHM）增加。含有0.65摩尔蒽的对三联苯薄膜的FWHM低至28.51nm。这种窄带蓝色发光掺杂发光体在发光二极管（OLED）和闪烁应用中很有需求。
