以LiF修饰阴极的有机电致发光器件性能的提高

提出了用一种无机半导体的模型来计算有机电致发光器件(OELDs)的J-V特性.通过在金属/有机物界面插入薄LiF层,由此引入的偶极子能极大地降低了电子的注入势垒和OELDs的开启电压.从而,载流子的注入得到了平衡,OELDs的性能得到了较大提高.经过数值计算,发现LiF插入层有一个约为1.5~5.0nm的最优厚度.LiF层太厚或太薄都会提高器件的开启电压、降低器件的性能.结果表明:这一模型可以用来解释OELD通过LiF修饰阴极后性能的提高.

Performance Enhancement by Modification of Cathode with a Thin LiF Layer in OELDs

A model for inorganic semiconductor has been presented to calculate theJ-Vcharacteristics of organicelectroluminescent devices(OELDs).The additional dipole energy introduced by inserting a thin LiF layer at metal/organic interface significantly decreases the potential barrier for electrons injection and the turn-on voltage of OELD.The charge carriers injection has been balanced,and then the performance of OELD has been greatly enhanced.Bydetailed numerical calculation,it has been found that the optimal thickness of inserted LiF should be in the range of1.5 ~5.0 nm,too thick or too thin LiF will increase the turn-on voltage of OELD and degrade its performance.It hasbeen proved that this model is proper to explain the performance enhancement of OELDs via modification of electrodewith LiF.