Luminescence Properties Of Organic Light-emitting Devices (OLEDs) With Inorganic Buffer Layer

Since Tang and Vanslyke reported their double-layer device in 1987, theorganic light-emitting devices (OLEDs) attracted more and more attention all over theworld because of their potential applications in solid-state illumination flat paneldisplays.High-luminance and high efficiency organic light-emitting diodes (OLEDs) werealways expected for their future applications. It was an effective ways to achieve highperformance by inserting buffer layer between organic layer and the anode. In this paper.we inserted MoOx and CuOx/Cu buffer layer between ITO and theHole-transporting-layer respectively, and we obtained some good result.By inserting the MoOx buffer layer, there are some advantages: (â…°) The turn-onvoltage decreased from 3.8V to 2.8V; (â…±) The maximum luminance value increasedfrom 6300cd/m~2 to 11000cd/m~2; (â…²) The operating current increased to thrice withoutefficiency changing.By inserting the CuOx/Cu buffer layer, The current density through OLEDsdecreases significantly brightness and efficiency. The optimized device has a highestbrightness of 14000cd/m~2 at 15V with efficiency of 3cd/A, which was about 50% morethan the control device. The highest efficiency of 5.9cd/A was achieved at 11.6V withbrightness of 3400 cd/m~2, it is almost twice as high as the control device.