Haze‐Suppressed Transparent Electrodes Using IZO/Ag/IZO Nanomesh for Highly Flexible and Efficient Blue Organic Light‐Emitting Diodes
Ho Jin Lee, Bo‐Hyun Kim, Ashkan Vakilipour Takaloo, Kyung Rock Son, Tukaram D. Dongale, Kyoung Moon Lim, Tae Geun Kim
Abstract
Abstract Nano‐mesh (NM) structures have been employed as flexible and stretchable electrodes for organic light‐emitting diodes (OLEDs). However, high optical haze induced by NM structures should be diminished while enhancing the transparency and lowering the sheet resistance simultaneously for their practical use. Herein, a highly flexible transparent electrode is demonstrated using indium zinc oxide (IZO)/Ag/IZO NM structure to satisfy all these requirements without complex designs in NM structures. The proposed NM electrode shows remarkably low haze (<10%), high optical transparency (>90%), and low sheet resistance (≈9.4 Ω sq –1 ), together with superior flexibility. Moreover, the smart NM‐based blue OLED shows characteristics of a Lambertian light source, with high external quantum efficiency (≈18.8%) and unprecedentedly outstanding bending properties. The experimental and theoretical analyses ascribe these improvements to the enhanced charge injection via conductive IZO with high work function as well as reduced surface reflection and diffraction of emitted light via anti‐reflective NM structure.