Highly Efficient p‐i‐n and Tandem Organic Light‐Emitting Devices Using an Air‐Stable and Low‐Temperature‐Evaporable Metal Azide as an n‐Dopant
Highly Efficient p‐i‐n and Tandem Organic Light‐Emitting Devices Using an Air‐Stable and Low‐Temperature‐Evaporable Metal Azide as an n‐Dopant
复制标题
DOI：
10.1002/adfm.201000137
复制
发表时间：
2010-06
影响因子：
19
通讯作者：
K. Yook;S. Jeon;Sung-Yong Min;Jun Yeob Lee;Hang Yang;Taeyong Noh;Sungkee Kang;Tae‐Woo Lee
中科院分区：
文献类型：
--
作者：
K. Yook;S. Jeon;Sung-Yong Min;Jun Yeob Lee;Hang Yang;Taeyong Noh;Sungkee Kang;Tae‐Woo Lee
叠氮化铯（CsN3）具有良好的空气稳定性和较低的沉积温度，是一种新型氮掺杂材料。CsN3在有机分子束沉积室中很容易与电子传输材料共沉积，由于其蒸发温度与普通有机材料相似，因此可以很好地作为电子传输层的n掺杂剂。CsN3掺杂的n型层和MoO3掺杂的p型层大大降低了p‐i‐n器件的驱动电压，并且该器件具有非常高的功率效率（57 lm W−1）。此外，n掺杂机理研究表明，CsN3在蒸发过程中被分解成Cs和N2。利用瞬态电致发光和电容电压测量对电荷注入机理进行了研究。使用由CsN3掺杂的n型有机层/MoO3 p型无机层组成的n - p结作为互连单元，还创建了非常高效的串联有机发光二极管（OLED; 84 cd A−1）。这项工作表明，空气稳定和低温可蒸发的无机n掺杂剂可以非常有效地提高p - i - n和串联oled的器件性能，并简化真空沉积过程中的材料处理。
Cesium azide (CsN3) is employed as a novel n‐dopant because of its air stability and low deposition temperature. CsN3 is easily co‐deposited with the electron transporting materials in an organic molecular beam deposition chamber so that it works well as an n‐dopant in the electron transport layer because its evaporation temperature is similar to that of common organic materials. The driving voltage of the p‐i‐n device with the CsN3‐doped n‐type layer and a MoO3‐doped p‐type layer is greatly reduced, and this device exhibits a very high power efficiency (57 lm W−1). Additionally, an n‐doping mechanism study reveals that CsN3 was decomposed into Cs and N2 during the evaporation. The charge injection mechanism was investigated using transient electroluminescence and capacitance–voltage measurements. A very highly efficient tandem organic light‐emitting diodes (OLED; 84 cd A−1) is also created using an n–p junction that is composed of the CsN3‐doped n‐type organic layer/MoO3 p‐type inorganic layer as the interconnecting unit. This work demonstrates that an air‐stable and low‐temperature‐evaporable inorganic n‐dopant can very effectively enhance the device performance in p‐i‐n and tandem OLEDs, as well as simplify the material handling for the vacuum deposition process.