KCl的纯度对OLED的影响

Effect of Purity of KCl on OLED Performances

KCl作为阴极修饰层插入电子传输层和阴极之间,能提高所修饰器件的亮度。但KCl的纯度对器件的影响究竟有多大,本文进行了研究。选取纯度为99.99%、99.5%与混有一定杂质的KCl(经测试纯度为95.3%),制作ITO/NPB(40nm)/Alq3(60nm)/KCl(1nm不同纯度)/Al结构的器件,并分别研究其亮度、电流密度和效率特性。发现随着KCl纯度的提高,器件的性能和电流密度有所提高,同时起亮电压降低。其中99.99%纯度的KCl所制备的器件性能最好,在16V时最大亮度为7585cd/m2,在9.4mA/cm2时最大效率为2.4cd/A。由此可见,阴极修饰层的纯度对器件的性能有较大影响。使用高纯度阴极修饰材料,防止其被污染,是制备器件所要考虑的因素之一。

KCl as electron injection layer was inserted between electron transport layer and cathode,it will improve the luminance of device. This paper studied the effect with different purity of KCl on OLED. Choosing KCl purity of 99.99%, 99.5% and 95.3%, the device with the structure Of ITO/NPB（40 nm）/Alq3 （60 nm）/ KCl（1 nm：different purity）/Al was fabricated. The characteristics of luminance, current density and efficiency was studied. It was found that with increasing the purity of KCl, the luminance and efficiency are increased, while the turn-on voltage is decreased. With 99.99% purity KCl as electron injection layer, the device has the highest luminance and efficiency, the maximum luminance is 7 585 cd/m^2 at 16 V and the maximum efficiency is 2.4 cd/A at 9.4 mA/cm^2. Consequently, the purity electron injection materials has a great influence on performance of device. Purifying the materials and protecting the materials from pollution, are the great factors that should he considered in fabricating the device.