Study On SSCL With Different Electron Accelerated Layers

Solid state cathodoluminescence(SSCL) is a kind of fire-new excitation mode. After the acceleration by accelerated layer using inorganic semiconductor, the electron has enough energy to excite the organic molecules and get luminescence by impact exaction. Blue light is the characteristic luminescence and the ionization of exaction is the unique process in SSCL. The SSCL are identified by ubiquitous certification by changing luminescence material. But some people doubt the blue luminescence was from SiO₂. In this paper, Si₃N₄ was used as acceleration material and MEH-PPV as luminescence material, SSCL was also obtained. So the possibility of the blue luminescence was from SiO₂ were excluded.A SSCL (solid state cathodoluminescence) device in which Si_N4 acts as the electronic accelerate layer and MEH-PPV acts as the luminescent layer is first designed. Under AC bias, SSCL of MEH-PPV is realized. The luminescence peak locates at 600 nm and 417 nm; respectively correspond to the exaction emission and the recombination luminescence of LUMO to HOMO. The intensity of these two peaks changes with the increasing of the driving voltage nonlinearly. Comparing to the device with SiO₂ as the accelerate layer, it is found that the short wavelength is same and locates at 417 nm in both two devices although their accelerate layer is 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 ability of Si₃N₄ and SiO₂ is compared at high driving voltage. The accelerating ability of SiO₂ is superior to that of Si₃N₄.One key to improve the efficiency of SSCL is improving ability of the electronic injection of the device. And the nanotube has a good characteristic of that. So, we used multi-wall nanotube as electronic injection layer.