An Alkane-Soluble Dendrimer as Electron-Transport Layer in Polymer Light-Emitting Diodes

Abstract

Polymer light-emitting diodes (PLEDs) have attracted broad interest due to their solution-processable properties. It is well-known that to achieve better performance, organic light-emitting diodes require multilayer device structures. However, it is difficult to realize multilayer device structures by solution processing for PLEDs. Because most semiconducting polymers have similar solubility in common organic solvents, such as toluene, xylene, chloroform, and chlorobenzene, the deposition of multilayers can cause layers to mix together and damage each layer. Herein, a novel semiorthogonal solubility relationship was developed and demonstrated. For the first time, an alkane-soluble dendrimer is utilized as the electron-transport layer (ETL) in PLEDs via a solution-based process. With the dendrimer ETL, the external quantum efficiency increases more than threefold. This improvement in the device performance is attributed to better exciton confinement, improved exciton energy transfer, and better charge carrier balance. The semiorthogonal solubility provided by alkane offers another process dimension in PLEDs. By combining them with water/alcohol-soluble polyelectrolytes, more exquisite multilayer devices can be fabricated to achieve high device performance, and new device structures can be designed and realized.

Preparation and characterization of silicone rubber through the reaction between γ‐chloropropyl and amino groups with siloxane polyamidoamine dendrimers as cross‐linkers

“…Owing to their superior characteristics, such as high symmetry, nanoscopic scale, well‐controlled molecular shape, unique monodispersity, and multi‐functionality, they have been widely developed in recent years . Especially, a large number of chemically reactive sites at the termini or in the cavities offers many opportunities for potential applications in many fields, such as biomedicine, surface chemistry, luminescence, and catalysis . Dendrimers have also been explored as cross‐linkers into polymer to achieve novel technological applications .…”

Dark Current Reduction Strategy via a Layer-By-Layer Solution Process for a High-Performance All-Polymer Photodetector

“…According to the Beer−Lambert law, absorption intensity is proportional to the film thickness. 25,26 To confirm the semiorthogonal solvent system for sequential processing, we measured the UV−vis absorption of these films before and after solvent rinsing. The UV−vis absorbance intensity of the PTzBI-Ph thin film remained at 80% of its original value after rinsing with neat MeTHF (Figure 1b).…”

“…Specifically, N2200 was processed from its MeTHF solution on top of the prefabricated PTzBI-Ph layer, ultimately yielding a favorable vertical phase separation of the bilayer-structured photoactive layer (referred as PTzBI-Ph/N2200, and the one-step solution-processed blend film was referred as PTzBI-Ph:N2200). According to the Beer–Lambert law, absorption intensity is proportional to the film thickness. , To confirm the semiorthogonal solvent system for sequential processing, we measured the UV–vis absorption of these films before and after solvent rinsing. The UV–vis absorbance intensity of the PTzBI-Ph thin film remained at 80% of its original value after rinsing with neat MeTHF (Figure b).…”