熱蒸鍍法製備布拉格反射鏡與有機微共振腔結構及其特性研究

Abstract

本研究係利用熱蒸鍍法製備高低介電質材料所堆疊之布拉格反射鏡（DBR），且將DBR與有機發光材料Alq3結合，形成一DBR/ Alq3/Ag所構成之有機微共振腔，並以光激發光（PL）形式觀察其發光特性之變化。 所選用的高低介電質材料為Sb2O3折射係數nH=2.0與MgF2折射係數nL=1.38，其蒸鍍條件穩定、速率控制容易，在DBR的製備上，可依我們所設計之波長得到對紅光、綠光、藍光之DBR，且反射率都可達到□99％，且與理論計算情形吻合；其DBR與作用層Alq3所構成之有機微共振腔結構，其PL發光光譜由原Alq3之發光波長半高寬（FWHM）100nm，窄化成9 nm，可得到一純色之綠光；我們也將作用層進行□/2厚度的微調，發現發光波長亦會隨之變動，且有相同窄化之情形。

In this thesis, we fabricated distributed Bragg reflector made of high and low refractive indices dielectric materials. The microcavity was sandwiched between a DBR and a metal Ag reflective minor. The 8-hydroxyquinline aluminum (Alq3) was used as the light-emitting layer. Photoluminescence from those devices was also investigated by using Xe lamp excitations. Properly choosing high and low refractive index dielectric materials Sb2O3 (nH=2.0) and MgF2 (nL=1.38), vaporization condition can be stable and the deposition rate is easily controlled. Before preparing DBR, the precise thickness of the dielectric material for specific right should be calculated to reach up the reflectivity □99%. Different frequency of light needs different thickness of the material to get construct interference. The experimental results have coincided with the theoretical prediction. The PL spectrum of Alq3 film was broad with a FWHM of 100 nm. The PL peak of the organic microcavity was narrowed down to a FWHM of 9 nm. The pure green light could be obtained. We can fine tuned the Alq3’s thickness to emit different wavelength with keeping same narrow peak.