Novel electrical-chemically polished stainless steel anode organic light emission device with long lifetime at high luminance for flexible lighting

Stainless Steel (s.s.) sheet substrate was electrical-chemically polished. Afterwards its average surface roughness reached 1.93nm. Then Organic Light Emission Devices (OLEDs) were fabricated on it with Alq₃ as the light emission material (EM) (called Devices SSA). So high-thermal-conductive s.s. was made use of directly as anode in Devices SSA. Lighted at initial luminance intensity 1135 cd/m², Devices SSA decayed to its half luminance after 18 hours (hrs) in the vacuum which has pressure of 5X10^-3 Pa. At the same time, top emission OLEDs with evaporated aluminum anode on glass (called Devices AA) were fabricated with the same EM. Devices AA have 20.5 hrs half lifetime but much lower initial luminance intensity 296cd/m², as measured in the same vacuum condition. The maximum luminance (L_max) of Devices SSA is 61,200cd/m², which is 2.3 times as high as L _max of Devices AA. In this paper, Device SSA with s.s. substrate thickness 0.05mm and bending radius 2mm is demonstrated. It indicates a bright future of flexible lighting application. White OLEDs on this substrate is being researched and longer lifetime could be achieved soon under better condition.