To improve the performance of tandem organic light-emitting diodes(OLEDs), we study the novel NaCl as n-type dopant in Bphen:NaCl layer. By analyzing their relevant energy levels and carrier transporting characteristi...To improve the performance of tandem organic light-emitting diodes(OLEDs), we study the novel NaCl as n-type dopant in Bphen:NaCl layer. By analyzing their relevant energy levels and carrier transporting characteristics, we discuss the mechanisms of the effective charge generation layer(CGL) of Bphen:NaCl(6 wt%)/MoO3. In addition, we use the Bphen:NaCl(20 wt%) layer as the electron injection layer(EIL) combining the CGL to further improve the performance of tandem device. For this tandem device, the maximal current efficiency of 9.32 cd/A and the maximal power efficiency of 1.93 lm/W are obtained, which are enhanced approximately by 2.1 and 1.1 times compared with those of the singleemissive-unit device respectively. We attribute this improvement to the increase of electron injection ability by introducing of Bphen:NaCl layer. Moreover, the CGL is almost completely transparent in the visible light region, which is also important to achieve an efficient tandem OLEDs.展开更多
基金Patent Industrialization Project of Shaanxi Province(No.2005ZZ-04)Industrialization Project of Shaanxi Education Office(No.06JC23)Patent Scientific Research Project of Shaanxi Education Office(No.07JK191)
基金Project supported by the National Natural Science Foundation of China(Grant No.60906022)the Natural Science Foundation of Tianjin,China(Grant No.10JCYBJC01100)+1 种基金the Scientific Developing Foundation of Tianjin Education Commission,China(Grant No.2011ZD02)the Key Science and Technology Support Program of Tianjin,China(Grant No.14ZCZDGX00006)
文摘To improve the performance of tandem organic light-emitting diodes(OLEDs), we study the novel NaCl as n-type dopant in Bphen:NaCl layer. By analyzing their relevant energy levels and carrier transporting characteristics, we discuss the mechanisms of the effective charge generation layer(CGL) of Bphen:NaCl(6 wt%)/MoO3. In addition, we use the Bphen:NaCl(20 wt%) layer as the electron injection layer(EIL) combining the CGL to further improve the performance of tandem device. For this tandem device, the maximal current efficiency of 9.32 cd/A and the maximal power efficiency of 1.93 lm/W are obtained, which are enhanced approximately by 2.1 and 1.1 times compared with those of the singleemissive-unit device respectively. We attribute this improvement to the increase of electron injection ability by introducing of Bphen:NaCl layer. Moreover, the CGL is almost completely transparent in the visible light region, which is also important to achieve an efficient tandem OLEDs.
