有机发光器件中缺陷态行为表现

The Actions of Defect-states in Organic Light Emitting Diodes

对有机发光二极管 (OL ED)的 I- V特性曲线 ,用有内建电场 Ei 的修正 F- N模型 ,或陷阱电荷限制电流 (TCL)模型进行了模拟分析 ,均观察到缺陷态对器件特性的影响。对修正 F- N模型拟合 ,Ei 不是常数而是随电场变化的 ;对满足 TCL 模型的 OL ED器件 ,其 I- V特性呈现类似于无机半导体器件中的“迟滞回线”状 ,而且随测试次数的变化呈现可恢复的变化。这些均说明 OL ED中存在着缺陷态。

The results simulated the I-V curves fo OLED which are whichever suitable to revised F-N model with built-in electrical field E i or trap-charge-limited current (TCL) model,indicate that the defect states exist in OLED.They have influenced the I-V characteristics of the OLEDs.For simulating of some OLED obeyed revised F-N model,we have to use an inner building electric field E i varied with bias for simulation of the I-V curves.For simulating of some OLED obeyed TCL model,then we can see a 'hesitated I-V curve' which is similar as in semiconductors devices with defect states.The hesitated I-V characteristics will drift with applied voltage and have some ability to be recovered.These effects would cause form and can be explained by the charges trapped in or draw-out from the defect-states with applied voltage.