Highly Promoting the Performances of Polymer Light-Emitting Diodes via Control of the Residue of a Polar Solvent on an Emissive Layer
journal contributionposted on 18.05.2017, 00:00 by Qiaoli Niu, Hengsheng Wu, Wentao Huang, Jing Tong, Fengye Ye, Yong Zhang, Wenjin Zeng, Ruidong Xia, Yonggang Min
The polar solvent dimethylformamide (DMF) was used to treat the emissive layer (EML) of polymer light-emitting diodes (PLEDs). The formation of a dipole layer at the EML/cathode interface after DMF treatment was proven, which led to a reduction of the electron-injection barrier. The dipole layer was formed mainly because of the intrinsic polarity of DMF. By control of the residue of DMF on the EML, a maximum enhancement of the peak luminous efficiency from 5.33 ± 0.57 to 12.05 ± 1.2 cd/A was achieved. This study suggests that solvent treatment is a simple and efficient approach to realizing highly efficient PLEDs with a high-work-function metal cathode.