有機發光二極體之有機與金屬界面動態特性模型擬合研究

The Study of Dynamical Characteristics of Organic /Metal Interface in Organic Light Emitting Diode – Data Fitting

簡柏叡(Po-Jui Chien)

指導教授 ： 楊恆隆

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00437

摘要

本論文研究，依據理論模型，擬合實驗所得之角頻譜數據以探討有機發光二極體在操作狀態下，有機層/金屬層界面間所產生的動態變化。先前研究結果已證實金屬層與有機層界面間存在一層中間層，本論文所建構之理論模型係根據此項結果，將此中間層定義為一介電層，以構成數據擬合所使用之5層有機發光二極體之結構，依據有機發光二極體量測所得之實驗數據，使用簡形數值擬合法將所得之實驗數據進行數據擬合，可由擬合所得介電層光學常數(n, k)以及厚度(d)，顯現界面動態的變化。而本數據擬合法誤差容許度最小可至2.68×10-5，由擬合結果可發現n值介於1.5~5間，k值介於4.5~8間，厚度則介於7.73~1.05(nm)間，與先前研究證實此層為極薄的中間層相符，並且可發現以波長632.8(nm)量測各元件時n、k變化率與電壓呈現正比關係居多，以685(nm)量測各元件時n、k變化率與電壓沒有呈現比例關係居多。綜觀所擬合出之介電層各項結果，可知此介電層擁有高折射率以及不易透光之高吸收率類金屬的特性。

關鍵字

有機發光二極體 ； 有機/金屬界面 ； 反射率 ； 光學常數 ； 簡形數值擬合法

並列摘要

This thesis research is to further investigate the dynamical behavior of organic/metal
interface in organic light-emitting diode (OLED) during operation by means of fitting experimental reflectivity data to the theoretical model. Previous study has shown the existence of a thin intermediate layer between organic layer and metal cathode. This thin intermediate layer is regarded as a dielectric layer in our theoretical model with optical constants (n, k ) and its thickness (d) as material parameters to fit reflectivity data by using Simplex method. The dynamical behavior of organic/metal interface in OLED during operation can be indicated by the variation of material parameters of the dielectric layer. Our research results revealed that the tolerance of data fitting could reach 2.68×10-5. The magnitude of n ranges between 1.5 and 5.11 after best fit. The magnitude of k ranges between 4.45 and 7.61 after best fit. The thickness ranges between 1.05 and 7.73(nm), coincided with the result of ultra-thin intermediate layer in previous study. The variation of n and k for some OLED devices inclines to increase as operation voltage increase under 632.8(nm) incident wavelength. The variation of n and k for some OLED devices inclines to remain unchanged as operation voltage increase under 685(nm) incident wavelength. This dielectric layer in our theoretical model for indicating dynamical behavior of interface could be characterized as a high absorption metal-like material coincided with the existence of carrier injection.

並列關鍵字

Organic Light-emitting Diode ； Organic/metal interface ； Reflectivity ； Optical constant ； Simplex method

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