Organic / Inorganic Cluster Compounds Luminescent Material And A New Hole Transport Materials Design, Synthesis And Device Development

Since the reports of C.W. Tang and VanSlyke in 1987, organic light emitting diodes have become a new and fascinating area of research. The advantages of organic light emitting diodes over other displays are high luminescence efficiency, wider selection of emission colors, super thin film, light weight, lower driving voltage. Since then, organic light emitting diodes (OLEDs) become one of the hotspots in the flat panel display.The past decades have seen great progress both in materials development and device fabrication techniques and green light-emitting materials have already been achieved with high brightness and efficiency. However, there are still many bottlenecks: The problems of the low efficiency and poor color purity for red-emitting materials and devices still remain. The efficiency and durability of blue-emitting ones are far from the practical application. The electron transport mobility of the present electron transporting materials is a factor of three orders of magnitude lower than the hole drift mobility.For full-color displays, efficient three primary colors, i.e. blue, green and red, are required. Red light-emitting materials, which fully meet the requirements for commercial application, are scarce because of the concentration-quenching problem. So we report the synthesis and structure of organic/inorganic clusters formed by linking Zn-S or Cd-S clusters with dye molecules. The basic idea is that the large cluster anion can separate the dye molecules more effectively. So, considering the influence of the spacer, quenching of dye molecules can be reduced significantly and fluorescence can be enhanced. And substituting for the halide atom may also enhance fluorescence. From experiments we can find that the emission intensity from organic/inorganic clusters was larger than that of the iodide analogue.So the salts were used as a rare host emitter in non-doped red OLEDs. The devices based on them emit in the red region with a maximum wavelength of 630 nm and the emission peak was so narrow that the full width at half maximum (FWHM) is only...