After the first report of electroluminescence (EL)

in poly(p-phenylenevinylene) (PPV)-based diodes

much effort had been devoted to the preparation of novel conjugated polymers in order to change the emission color and/or to increase the EL efficiency. All kinds of new materials and new techniques in the field of PLED have been developed in recent years

it promoted the development of PLED greatly. However

there are still some problems which block the industrialization of the PLED. The poly(p-phenylenevinylene) (PPV) is one of the familiar electroluminescent materials

which has the property of poor solubility

however. The soluble poly(2-methoxy-5-butoxy)-p-phenylene and poly(2-methoxy-5-octoxy)-p-phenylene with high yield were prepared by dehydrochlorination process in this paper. The product shows good solubility and film forming property

and the film was analysed with scanning electron micrograph(SEM)

the results showed that the PPV prepared have the property of excellent filming forming. Single-layer device and multi-layer device with Alq

3

as electron transfer layer and PEDOT as hole transfer layer have been prepared with PPV synthesized

and the property of electroluminescence have been studied. The effects of various factors to the light-emitting voltage and stability of the device

such as the purity of PPV

the thickness and quality of PPV films

and the structure and techniques of devices

have been studied in this paper also. The result showed that the multi-layer device is more stable than that of the single-layer device. The light-emitting starting voltage of the single-layer device is 4V

and the light-emitting starting voltage of the multi-layer device is 6V. The peak wavelength of the single-layer device and the multi-layer device are both at about 580nm.