| Summary: | 碩士 === 國立中央大學 === 光電科學與工程學系 === 101 === In this paper, we study ASE phenomenon of organic materials in a multilayer waveguide structure based on the general OLED device configuration. The method is to insert a spacer between the transparent electrode (ITO) and the organic emitting layer (BSB-Cz) to reduce the optical losses introduced by the ITO electrode. In the experiments, we observe that by inserting an organic polymer hole transport layer (PVK) with the refractive index lower than BSB-Cz and the thickness optimized, the ASE threshold energy can be reduced down to about 0.78 uJ/pulse, similar to as when BSB-Cz is directly deposited on the glass substrate. The main reason is that insertion of PVK can restore the waveguide mode profile and reduce the optical losses in ITO layer. However, we didn’t observe the ASE obviously when inserting the electron transport layer (TiO2) with a higher refractive index than BSB-Cz. The reason is that the high refractive index of TiO2 results in the photons essentially confined in the TiO2 layer, and hence decreasing the photon light amplification mechanism in the organic emitting layer. Finally, we simulate one dimension DFB resonator, to find out the suitable period such that the resonant wavelength can match the peak gain wavelength of organic materials. This study can be applied to multilayer waveguide structure, and the future development of electrically pumped organic lasers.
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