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.

Photoelectron spectroscopy of m-xylylene anion

Abstract: The 351-nm photoelectron spectrum of the negative ion of 1,3-benzoquinodimethane (m-xylylene) is reported. Features are observed in the photoelectron spectrum corresponding to formation of the 3 B2, 1 A1, and 1 B2 states of m-xylylene. The electron affinity of the triplet ground state is found to be 0.919 ( 0.008 eV, and vibrational frequencies of 290, 540, and 1500 cm -1 are obtained. The active modes are assigned to R-carbon bending, ring deformation, and methylene bending, respectively. The 1 A1 state is found to lie 9.6 ( 0.2 kcal/mol higher in energy than the ground state, in good agreement with theoretical predictions. Vibrational frequencies of 265, 1000, and 1265 cm-1 are found for this state. The 1B2 is estimated to be <21.5 kcal/mol higher in energy than the ground state. Density functional calculations have been carried out on the negative ion, indicating that the 2 B1 ion is a minimum on the potential energy surface, lying 2.9 kcal/mol lower in energy than the 2 A2 ion, which is a transition state.

Bulk transport measurements in ZnO: the effect of surface electron layers

Abstract: Magnetotransport measurements and x-ray photoemission spectroscopy were used to investigate the surface conductivity of ZnO Near-surface downward band bending, consistent with electron accumulation, was found on the polar and nonpolar faces of bulk ZnO single crystals A significant polarity effect was observed in that the downward band bending was consistently stronger on the Zn-polar face and weaker on the O-polar face The surface electron accumulation layer was found to significantly influence the electrical properties of high resistivity, hydrothermally grown bulk ZnO crystals at temperatures below 200 K, and is largely responsible for the anomalously low electron mobility reported for this material

Electronic structure, spin-orbit coupling, and interlayer interaction in bulk MoS 2 and WS 2

Abstract: Angle-resolved photoemission spectroscopy experiments reveal that the valence band splitting at $K$ point in transition metal dichalcogenides is primarily due to the spin-orbit coupling rather than inter-layer interactions. The authors have achieved convincing agreement between experimental results and theoretical calculations over a wide energy range.

Vacuum ultraviolet photoelectron spectroscopy of (NH4)2S‐treated GaAs (100) surfaces

Abstract: The surface chemistry and band bending of the ammonium sulfide‐treated GaAs (100) surface has been studied using surface‐sensitive synchrotron radiation photoemission spectroscopy. We find that the treatment leaves the GaAs surface terminated with roughly a monolayer of sulfur bonded to both As and Ga atoms. An n‐type barrier height of 0.8 eV is measured. The thermal stability of the various chemical components is studied and various issues of the passivating mechanism are discussed.

Photoelectron spectrum of isolated ion-pairs in ionic liquid vapor.

Abstract: The gas-phase valence binding energy spectrum of isolated ion-pairs of the commonly used [1-ethyl-3-methylimidazolium][bis(trifluoromethylsulfonyl)imide)] room-temperature ionic liquid is obtained by photoionization of a molecular beam of ionic liquid vapor by extreme ultraviolet light. The isolated ion-pair nature of the ionic liquid vapor is corroborated by single photon ionization mass spectroscopy, complemented by computed vaporization energetics of ion-pairs and clusters of ion-pairs. The valence binding energy spectrum of the isolated ion-pairs is discussed in comparison with available liquid-phase data and theoretical density functional theory calculations.