用Si3N4作为电子加速层制备了固态阴极射线发光器件,其中发光层为聚[2-甲氧基-5-(2-乙基-己氧基)-1,4-苯撑乙烯撑](MEH—PPV).在交流电压的驱动下,实现了MEH—PPV的固态阴极射线发光.与SiO2做电子加速层的器件进行了对比研究,两种器件在交流电场的驱动下都得到了波峰位于417nm的短波长发光峰,它来自有机物中电子从最低未占分子轨道到最高占据分子轨道的直接复合发光,这进一步证明了固态阴极射线理论的正确性.在交流高场下比较了Si3N4和SiO2的电子加速能力,发现SiO2的电子加速能力要优于Si3N4的电子加速能力.
A solid state cathodoluminescence (SSCL) device in which Si3N4 acts as the electronic accelerating layer and poly (2- methoxy-5-(2-ethyl-hexyloxy)-1, 4-phenylene vinylene (MEH-PPV) as the luminescent layer is first designed. Under alternating current bias, SSCL of MEH-PPV is realized. The luminescence peak is located at 600 and 417 nm, respectively, corresponding to the exciton emission and the recombination luminescence of lowest unoccupied molecular orbital (LUMO) to highest occupied molecular orbital (HOMO). The intensity of the two peaks changes with the increasing of the driving voltage nonlinearly. Compared with the device with SiO2 as the accelerating layer, the short wavelength emissions are found to be the same and located at 417 nm for both devices, although their accelerating layers are different. It confirms the SSCL theory and the short wavelength is caused by the direct recombination of electrons in LUMO and holes in HOMO. Finally, the accelerating abilities of Si3 N4 and SiO2 are compared at high driving voltage, which showed that the accelerating ability of SiO2 is superior to that of Si3 N4 at the driving voltage involved.