Electroluminescence Characteristics of Light-Emitting Devices Using Soluble Conducting Polymers
Yan Jinliang, Zhu Changchun,Li Guangze,Wei Wei
(Xi'an Jiaotong University,Xi'an 710049,China)

Abstract: The soluble MEH-PPV polymer is synthesized by using the dehydrochlorination reaction. An emitting layer of MEH-PPV is employed to fabricate single layerelectroluminescent devices TO/MEH-PPV/Al and double layer electroluminescent devices ITO/MEH-PPV/Alq₃/Al. An investigation is made on the electroluminescence spectra, I-Vand B-Vof the devices.The energy theory is applied to exhibit the  characteristic changes of all devices. It is found that the recombination of holes and electrons of single and double layer devices occurs in the MEH-PPV layer. Relative to the single layer MEH-PPVdevice, the light output at reduced current density in double layer devices is improved greatly with an additional Alq₃ film that serves as a hole blocking/electron transport layer.
Keywords: electroluminescence;polymer;theory of energy band