Theoretical studies in photoelectron spectroscopy: Use of angular distribution data to deduce molecular orbital parameters

The photoelectron spectra of the tautomeric 1,2,3,- and 1,2,4-triazole and 1,2,3,4-tetrazole systems have been compared with the corresponding N-methyl derivatives. The dominant tautomers in the gas phase have been identified as 2 H-1,2,3-triazole, 1 H-1,2,4-triazole and 2H-tetrazole.Full optimisation of the equilibrium geometry by ab initio molecular orbital methods leads to the same conclusions, for relative stability of the tautomers in each of the triazoles, but the calculations wrongly predict the tetrazole tautomerism.

Download Full-text

Transmission of substituent effects in heterocyclic systems. Application of molecular orbital parameters to the solvolysis of 4-substituted 1-(2-furyl)ethyl systems

The Journal of Organic Chemistry ◽

10.1021/jo00981a023 ◽

1972 ◽

Vol 37 (16) ◽

pp. 2623-2625 ◽

Cited By ~ 4

Author(s):

Donald S. Noyce ◽

Hernan J. Pavez

Keyword(s):

Molecular Orbital ◽

Substituent Effects ◽

Orbital Parameters ◽

Substituted 1

Download Full-text

Evidence for the Photoemission Nature of Gd 4f Resonant Photoemission

MRS Proceedings ◽

10.1557/proc-524-197 ◽

1998 ◽

Vol 524 ◽

Author(s):

S. R. Mishra ◽

T. R. Cummins ◽

W. J. Gammon ◽

G. D. Waddill ◽

G. Van der-Laan ◽

...

Keyword(s):

Angular Distribution ◽

Cross Section ◽

Photon Energy ◽

Photoelectron Spectroscopy ◽

Emission Cross Section ◽

Linear Dichroism ◽

Constructive Interference ◽

Resonant Photoemission ◽

Magnetic Linear Dichroism ◽

Spectroscopy Experiment

ABSTRACTThe constructive interference between direct and indirect channels above the absorption threshold of a core level leads to a massive increase in the emission cross section leading to a phenomenon called “resonant photoemission”. Using novel magnetic linear dichroism in angular distribution photoelectron spectroscopy experiment we have tried to understand the nature of the resonant photoemission process in Gd metal. The presence of dichroism in Gd 4f photoemission intensity at a photon energy corresponding to resonant photoemission clearly demonstrates the photoemission-like nature of the resonant photoemission process.

Download Full-text

A Study of Interfacial Electronic Structure at the CuPc/CsPbI2Br Interface

Crystals ◽

10.3390/cryst11050547 ◽

2021 ◽

Vol 11 (5) ◽

pp. 547

Author(s):

Zengguang Tang ◽

Liujiang Zhang ◽

Zhenhuang Su ◽

Zhen Wang ◽

Li Chen ◽

...

Keyword(s):

Electronic Structure ◽

Molecular Orbital ◽

Photoelectron Spectroscopy ◽

High Performance ◽

Energy Gap ◽

Hole Transport ◽

Hole Injection ◽

Band Bending ◽

Valance Band Maximum ◽

Interfacial Electronic Structure

In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.

Download Full-text