New (lv North) Polyimide Light-emitting Diodes

There are increasing researchers show interest in polymer light-emitting diodes (PLED),and people believe that PLED will be the most powerful competitor for panel display in future. This paper is about a novel PLED with fluorene-based cardo perylene polyimide (PFB5) and a fluorine contained PFB5,PFF5 as the emitter. The research work in this paper is as follows.1. Study on the physical character,chemical character of PFB5,and the UV and photoluminescence (PL) spectra of PFB5 in chloroform solution and in film state. Using PFB5 or PFB5 doped with PBD as the emitter,we fabricate single layer polymer LED. Also multiplayer devices,ITO/PFB5/PBD/A1 and ITO/PFB5/Alq/Al have been fabricated. Finally,we got these devices' I-V curve,V-brightness curve,and spectra.2. Another fluorine-contained polyimide,named PFF5,which has the ability to transfer electron,has been studied too. Similar to PFB5,this polymer has high thermal stability,and the TG is above 330. Excitation at 493nm,the emission peaks of PFF5 in chloroform solution is 540nm and 580nm. Using PFF5 as the emitter,an efficiency single layer LED has been fabricated.3. In the system of PFB5 and PFF5,fluorene units and perylene units were incorporated into polyimide chain. As we know,in the molecule light emitting diodes,to get color tunable and high efficiency,there are energy shift from host to dopant. In the PFB5 and PFF5 LED,we also find the energy shift from host to dopant intra-chain. And it will be a new way to realize high stability and efficiency polymer LED.4. An approach to realize all-color display is using micro-cavity effect for polymer LED. Using the bi-refraction effect of liquid crystal,we design a novel wavelength tunable micro-cavity polymer LED. Exert a voltage to liquid crystal;it will be realize the emission wavelength tunable. The simulation indicates that the tunable range can approach 60nm,and the FWHM is 18. 5 nra.The innovation of this paper can be expressed in 6 points:1. Study on the PL and EL character of fluorene-based cardo perylene polyimide,PFB5 and PFF5.2. Do research on the intra-chain energy shift of the polyimide.3. Do research on the tunable micro-cavity polyimide light-emitting diodes.