Electron Transport Materials for Organic Light-Emitting Diodes: Understanding the Crystal and Molecular Stability of the Tris(8-hydroxyquinolines) of Al, Ga, and In

Abstract

An experimental and theoretical study on the phase and molecular stability of Mq3 (M = Al, Ga, and In; q = 8-hydroxyquinoline) is presented. The results suggest that the energy difference between the meridional and facial isomers of Mq3 shall be significantly lower than previously though and provide an explanation for the reported mer–fac solid–solid transition. The first accurate vapor pressure measurements for Alq3, Gaq3, and Inq3 are presented, which are of great relevance for the manufacturing of thin films by vacuum deposition. Phase transition thermodynamics indicates higher cohesive energies of the mer-isomers and an entropic differentiation that can be associated with the different molecular symmetry of the mer- and fac-isomers.

Structural, electronic and magnetic properties of 8-hydroxyquinoline-based small molecules TMQx (TM=Cr, Mn, Fe, Co, Ni, Cu, Zn, and x=2 or 3)

“…Furthermore, these molecules are even more fascinating due to their charming potential in molecular motors or generators [10]. In particular, metal 8-hydroxyquinoline complexes (TMQ x , x ¼2 or 3, with two or three 8-hydroxyquinoline ligands and a metal atom in the center) are widely used in organic lightemitting diodes (OLEDs) and organic solar cells in the light of their excellent optoelectronic properties [11,12]. Among them, tris(8-hydroxyquinoline) aluminum (AlQ 3 ) is a typical example.…”

Morphology of Imidazolium‐Based Ionic Liquids as Deposited by Vapor Deposition: Micro‐/Nanodroplets and Thin Films

“…In addition, SEM images of IL droplets prepared on ag olds urfacea re pre-sented as SupportingI nformation. [53][54][55][56][57] Furthermore, the deposition of organic semiconductor (OSC) materials ontoI Ls and the growth of OSC crystals and/or thin films has been already reported. [49] In other literature reports, metal deposition onto ILs leads to particle formation within the IL [50,51] and two-dimensionally organized gold particles formed during IL/metal sputterd eposition remaining at the surfaceo fI Ls were reported only recently.…”

Systematic study on charge transport and spectroscopic properties: a DFT Benchmark of LCD’s molecules

“…We have been chosen M06-2X, w-B97XD, CAMB3LYP and B3LYP functionals and 6-31+G*, 6-31+G** basis sets to describe molecules based in branched mesoionic centers to generate a discotic-like molecular electronic devices [4] considering Alq 3 such as the reference molecule [2,3].…”

“…Nowadays we have been faced with a large quantity of papers, works and device due the technological improvements of TV's and monitors, OLED's and LCD's, in the last years [1]. So, in this work we have been investigated LCD's molecules focusing the development of a database of electron/hole transfer and spectroscopic properties [2,3]. In this sense, a DFT benchmark has been created to evaluate these properties that have a large dependence of functionals and basis sets.…”