LiF作为电子注入层对OLEDs器件性能的影响(英文)

Effect of LiF as Electron Injection Layer on OLEDs

制造了两种OLEDs器件,它们的结构分别为:ITO/NPB(50nm)/Alq3(65nm)/Mg∶Ag(10∶1)(100nm)/Ag(50nm)andITO/NPB(50nm)/Alq3(65nm)/LiF(x)/Al(100nm)。结果发现,在同样电压下,与Mg∶Ag/Ag电极相比,插入LiF层可以明显提高器件的电流。当LiF厚度为1nm时,器件性能最好。以Mg∶Ag/Ag合金作为电极时的器件的最大亮度为8450cd/m2,而插入LiF层的器件最大亮度可达到14700cd/m2。此外,器件的发光效率也得到了明显的提高,在7V时达到了最大为3.117cd/mA。同时,当LiF厚度大于1nm或小于1nm时,器件性能都将会下降。

Two kinds of OLEDs were fabricated. Their structures are respectively as follows： ITO/NPB（50 nm）/Alq3（65 nm）/Mg：Ag（10：1）（100 nm）/Ag （50 nm） and ITO/NPB （50 nm）/Alq3（65 nm）/LiF（x）/Al （100 nm）. The results show that it can increase the current of device obviously by inserting LiF layer compared with Mg ： Ag/Ag electrode at the same voltage. When the thickness of LiF layer is 1 nm, the performance is the best. Its maximal brightness can reach to 14 700 cd/m^2, while that of Mg：Ag/Ag alloy electrode device is only 8 450 cd/m^2. In addition, the luminous efficiency of the device mentioned above also has been obviously improved, and has reached to the maximum 3. 117 cd/mA under 7 V. Meanwhile, it is found that the performance will decrease along with the alteration of the thickness of LiF layer more or less than 1 nm.