以表面嵌鎳ITO 電極形成具選擇性發光之軟性OLED

Flexible Organic Light-Emitting Diode with Metal Interfaced Indium Tin Oxide Anode for Selective Light-Emitting

本文報導藉由表面摻雜或嵌入鎳的方式形成高功函數的氧化銦錫（ITO），作為軟性有機電激發光二極體 （OLED） 的陽極，此方式可以降低ITO/有機層間的能障，進而提昇OLED 的光電特性。以Al/Alq3/NPB/ITO為結構的OLED，當包含此表面嵌附鎳的ITO 陽極時，turn-on電壓可以降低至少2.0 V，這主要是因為介面存在的鎳或氧化鎳降低了介面能障與形成較佳的介面接觸，使電洞注入效率提昇。利用此方法，我們製作了具卡通形態的OLED 圖案，可以表現出選擇性發光的特性。

This article reports on the fabrication and performance of flexible organiclight-emitting diodes (OLED) using metal interfaced indium tin oxide(ITO) anodes. ITO films were either doped with nickel (Ni) using aco-sputter method or surface embedded with Ni using photolithographyand polishing approach to form a surface with high work function. Thishigh work function surface allows the potential barrier between ITO anodeand organic hole transport layer to be lowered and thus to enhance thecharacteristics of OLED devices. OLED devices with a structure of Al/Alq3/NPB/ITO exhibit reduced threshold voltage and turn-on voltage by atleast 2.0 V when using Ni-doped or Ni-embedded ITO at the NPB/ITO interface.The formation of a nickel oxide phase (forming high work function> 5.0 eV) and better contacts (increasing hole injection efficiency) atITO/NPB interfaces are suggested to be the main causes for the improvedcharacteristics. An OLED display performing a so-called selective lightemittingpattern with the Ni-doped ITO scheme is demonstrated.