X-Ray Spectroscopic Study of the Conduction Band of K₃:Anthracene and K₃:Phenanthrene

Abstract

We study anthracene and phenanthrene doped with potassium using X-ray absorption spectroscopy and electronic structure calculations. In addition, a comparison of molecular orbital calculations and solid state density functional theory calculations are presented. We find that potassium-doping partially populates the LUMO level of anthrancene and phenanthrene and that both the measured and calculated electronic structures of the doped systems are quite different from that of the pristine molecular systems. This suggests that the extra charge carriers in the doped system are responsible for the increased conductivity and greater intermolecular interaction. Finally, our calculations suggest that both K 3 :phenanthrene and K 3 :anthracene have reduced or nonexistent band gaps as compared to their pure counterparts, further supporting the conclusion that doping is responsible for increased conductivity.

Self-Alignment of the Methylammonium Cations in Thin-Film Organometal Perovskites

“…This hole reduces the screening of the nuclear charge, which tends to pull the local unoccupied orbitals to lower energies . Explicitly calculating the effect of the core hole on the ground-state electronic structure is a challenging task, so herein we use crystal field (CF) theory to approximate the influence of the core hole. CF is a very well-known approximation for determining the electronic structure of ionic compounds, and although it has largely been supplanted by ligand field theory or tight-binding models it is an appropriate approximation for modeling the core hole effect on insulating materials .…”

Precise control of single-phenanthrene junction’s conductance

“…It affords low electronic thermal conductance (<0.005 KB/h) with ignorable phononic thermal conductance that both enhance its thermoelectric efficiency [22]. The phenanthrene also shows a superconcutance when it is doped with alkali metals [23,24]. Therefore, in this paper, the phenanthrene was attached to two gold leads in para-para, para-meta, and meta-meta connectivities with one or two carbon atoms substituted with (linked to) nitrogen atom "dopant" (phenyl radical "side group").…”

Synthesis and photophysical properties of new reactive fluorophenanthrenes

“…Inspired by the literature, many phenanthrene derivatives have been synthesized, and their photophysical and thermal properties including their electrochemistry have been intensively studied. These derivatives offer access to various organic devices such as organic light-emitting diodes (OLEDs) [11][12][13][14][15][16][17][18], solar cells [19][20][21], superconductors [22,23], etc. In an independent study, Zhang and co-workers reported the synthesis of phenanthro-imidazole 1 (Figure 1) and used it for OLEDs [24].…”