Indium Tin Oxide Electrode with an Ultrathin Al Buffer Layer for Flexible Organic Light Emitting Diode

This paper reports that the mechanical and electrical stability of indium tin oxide (ITO) film deposited on flexible plastic substrate can be much enhanced with a thin Al buffer layer while maintaining a visible transmittance over 75%. The improved stability is attributed to the effective elastic mismatch between the film and the substrate reduced by a ductile interlayer. A polymer light emitting diode fabricated using an ITO/Al anode exhibited a luminance of 13,000 cd/m 2 with a current efficiency of 16 cd/A. Bending-induced degradation of the device performance was also alleviated when a mechanical buffer layer was inserted.