Influence of hole injection layer and work function of cathode on the performance of light-emitting liquid crystal cells with fluorescent dye-doped nematic liquid crystal

摘要

We investigated the properties of rubrene-doped nematic-liquid-crystal cells to help determine the appropriate structure and material of electrodes for inducing light emission. In particular, we addressed the influence of the insertion of a hole injection layer (HIL) and the work function of the cathode on device performance. As a result, the employment of a HIL and a lower-work-function material was revealed to be effective in obtaining higher luminance and external quantum efficiency. We concluded that this improvement is caused by the facilitated carrier injection on the HIL and cathode surface, as is true for common organic light-emitting diodes.