To investigate effective means of improving the efficiency of organic light-emitting devices （OLEDs） by making full use of ,triplet emission, a phosphorescent material Pt （II） Octaethylporphine （PtOEP） is doped into polymer host polyspirobifluorene （Spiro） to allow radiative recombination of triplet excitons. The current and brightness characteristics of the devices are tested and the electroluminescent spectra are described. Both fluorescence and phosphorescence are ob- served,and an obvious increase in external quantum efficiency is realized compared to undoped devices when different phosphorescent dopant concentrations are tried. Thus,the phosphorescent emission from triplet excited states might be an effective way to increase the efficiency of OLEDs when the concentration of the phosphorescent dopant is properiy controlled.
Transparent conducting oxide film of molybdenum-doped zinc oxide （MZO） with high transparency and relatively low resistivity was prepared by RF （radio frequency） magnetron sputtering at room temperature. The structural, electrical, and optical properties of the films deposited under different Ar pressure were investigated.XRD （X-ray diffraction） patterns show that the nature of the films is polycrystalline with a hexagonal structure and a preferred orientation along the c-axis. The resistivity increases as Ar pressure increases. The lowest range exceeds 88% for all the samples. The optical band gap decreases from 3.27 to 3.15 eV with increasing Ar pressure from 0.6 to 3.0 Pa.
Xianwu XIUZhiyong PANGMaoshui LVYing DAILi＇na YEShenghao HAN
