Study of White Electroluminescence from a Single-Component Polymer Using an Electrolyte-Gated Diode
journal contributionposted on 24.04.2017, 00:00 by Jiang Liu, Shu-Yu Chou, Kwing Tong, Xinning Luan, Fangchao Zhao, Qibing Pei, Huaping Li
White electroluminescence (EL) of a single-component polymer (SCP) in a polymer light-emitting diode (PLED) was measured to show blue-green and red emission peaked at 494 and 627 nm spectrally, the CIE coordinates of (0.36, 0.34), and a color temperature of 6247 K. The electric excited red emission is significantly different from the obtained photoluminescence (PL) spectrum, attributing to the formation of electromers under an electric field. The white EL of SCP was also investigated in an electrolyte-gated organic light-emitting diode in which the luminance of EL was tuned from 0.3 cd/m2 at VG = −4 V to 6000 cd/m2 at VG = 7 V under the diode bias of 8 V. Although the current efficiency of SCP diodes increased, the relative intensities of red emission with reference to blue-green emission decreased when switching gate potential from 0 to 8 V at a constant driving voltage. These results indicate the generation of electromers is favored with imbalanced charge carriers, besides the conformation changes of molecular moieties of SCP induced by diode bias.