Interfacial structure in organic optoelectronics

TL;DR

This paper investigates the interfacial structure in organic optoelectronic devices, revealing how interlayer composition and metal choice affect device performance through in-situ X-ray photoelectron spectroscopy analysis.

Contribution

It introduces a novel in-situ characterization method to analyze organic/inorganic interfaces and links interfacial structure to device performance.

Findings

Interfacial layer impacts device performance via lattice matching.

Different cathode metals produce distinct interfacial effects.

Interfacial oxidation by-products influence device efficiency.

Abstract

The interfacial structure plays a critical role in modern optoelectronics. Currently multilayer electrodes are used to optimize the injection and lifetime properties. The choice of interlayer is not universal, with different effects for the same material with different capping metals. Using a novel in-situ characterization method with X-ray photoelectron spectroscopy, the organic/inorganic interface in OLEDs was examined for two common cathode metals with a LiF interlayer. The impact of the interfacial layer on the performance of devices can be attributed to the bulk lattice matching of the interfacial layer and of the by-products of interfacial oxidation, and the metallic cathode.