The Optoelectronic Properties Of A Blue Bispyrazolopyridine

ABSTRACT:This work investigates light emitting properties of a blue fluorescent bipyrazolopyridine derivative material,4-(4-methylphenyl)-1,7-diphenyl-3,5,-dimethyl-dipyrazolopyridine (BPP1). First, the photophysical properties and energy structures of the BPP1 was studied. The absorption peak, the emission peak, excitation spectra and the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the BPP1 were investigated. Then, the electroluminescent devices were fabricated using BPP1 doped PVK as emitting layer. The structure of devices and the ratio doping were designed, the blue-ray devices of different structures and different doping ratio were made, and contrasting and discussing the performance of the devices. It showed that a reasonable proportion of device structure and doping can effectively improve the performance of the device. Finally, studying on the quenching properties of bipyrazolopyridine derivative material BPP1.The quenching of BPP1 were measured in acid,alkali, salts and acidic environment. It was found that bipyrazolopyridine derivative material BPP1 is seriously dynamic quenched by the H+ ions in strong acid, and the quenching of the BPP 1 is reversible as the pH change in the acid and alkali environment. The pH characteristics can be controlled to adjust the fluorescence intensity of BPP 1, such as the fluorescent switch. And it is a guidance of improving the making process of electroluminescent devices, no H+ ions is required when selecting the material of the supporting layer and environment of preparation, to avoid generating device quenching.