Photoemission spectroscopy

About: Photoemission spectroscopy is a research topic. Over the lifetime, 10821 publications have been published within this topic receiving 250888 citations. The topic is also known as: photoelectron spectroscopy & PES.

SiO2/Si(100) interface studied by Al Kα x‐ray and synchrotron radiation photoelectron spectroscopy

Abstract: Both synchrotron radiation photoemission spectroscopy (PES) and Al Kα photoelectron spectroscopy (XPS) are used to determine the suboxide distribution at SiO2/Si (100) interfaces. High resolution PES measurements clearly resolved various suboxides with chemical shifts of 0.97, 1.80, and 2.60 eV for Si+1, Si+2, and Si+3, respectively. A total of 9.3×1014 atoms cm−2 of suboxide is found by PES measurements while only 4.2×1014 atoms cm−2 is measured by XPS on the same sample. This discrepancy is neither caused, as previously believed, by a difference in SiO2/Si (100) quality nor by a difference in methodology in data analysis. The possible factors, e.g., electron mean‐free path and photoionization cross section, which contribute to the difference between PES and XPS data, are considered.

Chemical and electrical properties of interfaces between magnesium and aluminum and tris-(8-hydroxy quinoline) aluminum

Abstract: The chemistry, electronic structure, and electron injection characteristics at interfaces formed between tris(8-hydroxy quinoline) aluminum (Alq3) and magnesium (Mg) and aluminum (Al) are studied via x-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy, and current–voltage (I–V) measurements. Both metal-on-Alq3 and Alq3-on-metal interfaces are investigated. All interfaces are fabricated and tested in ultrahigh vacuum in order to eliminate extrinsic effects related to interface contamination. The propensity for Mg and Al to form covalent metal–carbon bonds leads to broad and heavily reacted interfaces when the metal is deposited on the organic film. For this deposition sequence, we propose the formation of an organometallic structure where a single metal atom attaches to the pyridyl side of the quinolate ligand of the molecule and coordinates with an oxygen atom of another ligand or of a neighboring molecule. The other deposition sequence leads to significantly more abrupt interfaces wh...

Characterization of the molecular parameters determining charge transport in anthradithiophene

Abstract: The molecular parameters that govern charge transport in anthradithiophene (ADT) are studied by a joint experimental/theoretical approach involving high-resolution gas-phase photoelectron spectroscopy and quantum-mechanical methods. The hole reorganization energy of ADT has been determined by an analysis of the vibrational structure of the lowest ionization band in the gas-phase photoelectron spectrum as well as by density-functional theory calculations. In addition, various dimers and clusters of ADT molecules have been considered in order to understand the effect of molecular packing on the hole and electron intermolecular transfer integrals. The results indicate that the intrinsic electronic structure, the relevant intramolecular vibrational modes, and the intermolecular interactions in ADT are very similar to those in pentacene.

High quality atomically thin PtSe2 films grown by molecular beam epitaxy

Abstract: Atomically thin PtSe2 films have attracted extensive research interests for potential applications in high-speed electronics, spintronics and photodetectors. Obtaining high quality, single crystalline thin films with large size is critical. Here we report the first successful layer-by-layer growth of high quality PtSe2 films by molecular beam epitaxy. Atomically thin films from 1 ML to 22 ML have been grown and characterized by low-energy electron diffraction, Raman spectroscopy and X-ray photoemission spectroscopy. Moreover, a systematic thickness dependent study of the electronic structure is revealed by angle-resolved photoemission spectroscopy (ARPES), and helical spin texture is revealed by spin-ARPES. Our work provides new opportunities for growing large size single crystalline films for investigating the physical properties and potential applications of PtSe2.