LiF修饰阴极的双层有机电致发光器件的延时效应

基于载流子的注入、传输和复合过程,建立了双层有机发光器件的电致发光延时理论模型;讨论了电致发光延时随电压、注入势垒、内界面势垒、阳极区厚度及LiF缓冲层(BL)厚度的变化关系。结果表明:(1)低电压下,EL延时由复合过程主导,而高电压下,输运过程起着更重要的作用;(2)当δe/δh2时,M/O界面属于欧姆接触,电流是空间电荷限制的,注入势垒的变化对复合时间trec影响较大,当δe/δh2时,M/O界面成为接触限制,注入势垒的变化对trec几乎没有影响;(3)当内界面势垒超过0.3eV,H′h对trec的影响明显变弱,复合延迟时间基本上由电压和其它因素控制;(4)当电压较小时,随Lh/L的增大,trec增大;当电压超过某一值后,trec几乎不随Lh/L的变化而变化;(5)对于LiF/Ag阴极,在不同的偏压下,LiF的厚度在3.1nm左右时的复合时间最短,对应的EL延迟时间也最短,这与实验中从电致发光效率的角度得出的LiF最佳厚度一致。     

可弯曲式微腔有机电致发光器件的光学特性

设计了结构为上反射镜/有机层/下反射镜/柔性基板的可弯曲式有机电致发光器件(FOLED)。利用几何光学模型计算了器件在不同弯曲情况下,其发光光谱随观测角和曲率的影响,并与平整器件的光谱作了比较。结果表明:1)基板向内弯曲时,随着观测角的增大,器件的发光光谱峰值出现蓝移,且蓝移的程度相对平整器件要大;随着曲率的增大,器件的发光光谱峰值出现蓝移。2)基板向外弯曲时,随着观测角的增大,器件的发光光谱峰值出现红移,但红移的程度不大;随着曲率的增大,器件的发光光谱峰值出现红移,且与基板向内弯曲时蓝移的程度相当。     

可弯曲式有机电玫发光器件的出光率

基于几何光学模型及其原理,推导出在不同弯曲情况下可弯曲式有机电致发光器件的出光率表达式,分析了器件出光率受基板曲率、厚度及有机层折射率的影响,并与平整有机电致发光器件的出光情况作了比较.结果表明:当器件向外弯曲时,出光率随着基板曲率与基板厚度的增大而增大,随着有机层折射率的增大而减小;当器件向内弯曲时,出光率随着基板曲率与基板厚度的增大而减小,随着有机层折射率的增大而减小.对于平整器件,其出光率随有机层折射率的增大而减小.     

An Electroluminescence Delay Time Model of Bilayer Organic Light-Emitting Diodes

Based on the mechanism of injection, transport and recombination of the charge carriers, we develop a model to calculate the delay time of electroluminescence （EL） from bilayer organic light emitting diodes. The effect of injection, transport and recombination processes on the EL delay time is discussed, and the relationship between the internal interface barrier and the recombination time is revealed. ＂]~he results show that the EL delay time is dominated by the recombination process at lower applied voltage and by the transport process at higher applied voltage. When the internal interface barrier varies from 0.15 eV to 0.3 eV, the recombination delay time increases rapidly~ while the internal interface barrier exceeds about 0.3eV~ the dependence of the recombination delay time on applied voltage is almost undiversified, which may serve as a guideline for designing of a high-speed EL response device.     

Tunable surface-plasmon-resonance wavelength of silver island films

This paper experimentally and theoretically investigates the effect of the underlayer medium on tuning of the surface plasmon resonance (SPR) wavelength of silver island films,and the effect of substrate temperature on the morphologies and optical properties of the films.From the absorption spectra of single Ag with various thickness and overcoated (Ag/TiO 2) films deposited on glass substrates at various substrate temperatures by RF magnetron sputtering,we demonstrate that the surface plasmon resonance wavelength can be made tunable by changing the underlayer medium,the thickness of metal layer and the substrate temperature.By varying substrate temperatures,the interparticle coupling effects on plasmon resonances of nanosilver particles enhance as the spacing between the particles reduces.When the substrate temperature is up to 500 C,the absorption peak decreases sharply and shifts to shorter wavelength side due to the severe coalescence between silver islands in the film.     

氧氩比对钴掺杂氧化锌薄膜光电性能的影响

以氧化锌陶瓷靶和金属钴靶为靶材,利用磁控共溅射方法制备钴掺杂氧化锌(Co-ZnO)薄膜。研究了氧氩比对薄膜的结构、光学和电学性能的影响。结果表明:薄膜具有类似于ZnO的六方纤锌矿结构,并沿c轴择优生长;当氧氩比为2:8时,薄膜具有较好的纳米晶粒和表面结构,其霍尔迁移率为2.188×104cm2/V·s,最小电阻率为1.326×104Ω·cm,其薄膜透光率最高,且在紫外区有一个相对较强的发射峰。