液晶与显示, 2016, 31 (8): 773, 网络出版: 2016-10-24
利用CsN3n型掺杂电子传输层改善OLED器件性能的研究
Improved properties of organic light-emitting devices by utilizing CsN3 n-type doped electron transport layer
摘要
为了能够有效地提高电子的注入和传输能力, 改善有机电致发光器件的性能, 本文利用CsN3作为n型掺杂剂, 对有机电子传输材料Bphen进行n型电学掺杂, 制备了结构为ITO/MoO3(2 nm)/NPB(50 nm)/Alq3(30 nm)/Bphen(15 nm)/Bphen∶CsN3(15 nm,x%, x=10,15,20)/Al(100 nm)的器件。实验结果表明, CsN3是一种有效的n型掺杂剂, 以掺杂层Bphen∶CsN3 作为电子传输层, 可以有效地降低电子的注入势垒, 改善器件的电子注入和传输能力, 从而降低器件的开启电压, 同时提高了器件的亮度和发光效率。在掺杂浓度为10%时器件的性能最优, 开启电压仅为2.3 V, 在7.2 V的驱动电压下, 达到最大亮度29 060 cd/m2, 是非掺杂器件的2.5倍以上。当驱动电压为6.6 V时, 达到最大电流效率3.27 cd/A。而当掺杂浓度进一步提高时, 由于Cs扩散严重, 发光区形成淬灭中心, 造成器件的效率下降。
Abstract
To enhance the electron injecting and transporting ability and improve the performance of organic light-emitting device,the organic electron transport material Bphen was electrically doped by using CsN3 as n-type dopant in this work. The devices of ITO/MoO3(2 nm)/NPB(50 nm)/Alq3(30 nm)/Bphen(15 nm)/Bphen: CsN3(15 nm, x %, x=10,15,20)/Al(100 nm) were prepared. The experimental results show that the CsN3 is an effective n-type dopant. The electron injection barriers was reduced and the electron injecting and transporting ability of the device was enhanced by using the Bphen: CsN3 doped electron transport layer. As a result, the turn-on voltage was decreased, and the brightness and the luminous efficiency of the device were improved.The optimal doping concentration of the device was 10%.The device shows a turn-on voltage of 2.3 V and the maximum luminance reaches 29 060 cd/m2 at 7.2 V, more than 2.5 times of that of the device without doping. The maximum current efficiency was 3.27 cd/A when the voltage was 6.6 V.When the doping concentration further increases,the efficiency of the device is decreased owning to Cs atom quenching the luminescence center induced by interdiffusion.
于瑶瑶, 陈星明, 金玉, 吴志军, 陈燕. 利用CsN3n型掺杂电子传输层改善OLED器件性能的研究[J]. 液晶与显示, 2016, 31(8): 773. YU Yao-yao, CHEN Xing-ming, JIN Yu, WU Zhi-jun, CHEN Yan. Improved properties of organic light-emitting devices by utilizing CsN3 n-type doped electron transport layer[J]. Chinese Journal of Liquid Crystals and Displays, 2016, 31(8): 773.