Organic light-emitting diodes based on PVK and Zn(II) salicylidene composites

In this article we exploited the electroluminescent properties of the bis-salicylidenes and some of their Zn(II) coordination compounds forming composites with PVK. The advantage of using the composites is the diodes were solution-processable instead of the vapour deposited process. The performance of these coordination compounds was compared with others using Alq3 and Znq2 compounds and we found that the Zn(II)-bis(salicylidenes) had greater performance and might be used as a low-cost green electroluminescent material. We also attempted to understand the nature of the EL emission and the role of the PVK matrix on the diode performances. For that we compared the EL and the photemission profiles and using the photolumincescence lifetimes and JxV plots we discussed the role of the energy transfer and the charge mobility on the optical-electronic properties of the devices, respectively.