Photoemission spectra of deuterated silicon clusters: experiment and theory

Abstract

We compare experimentally measured and ab initio computed photoelectron spectra of negatively charged deuterated silicon clusters (SimD − n , 4 ≤ m ≤ 10, 0 ≤ n ≤ 2) produced in a plasma environment. Based on this comparison, we discuss the kinetics and thermodynamics of the cluster formation and the effect of deuterium on the geometrical and electronic structure of the clusters.

Densely Packed ZnTPPs Monolayer on the Rutile TiO2(110)-(1 × 1) Surface: Adsorption Behavior and Energy Level Alignment

“…LDA, GGA): (a) the Kohn-Sham energy levels yield transport gaps for the organic molecules that are usually too small; 21, 42-43 and (b) the initial relative level alignment between the oxide and the organic materials is not correctly described even in well converged LDA (or GGA) calculations. 44-47 Following up previous publications, 48-50 we have introduced two operators to amend these problems. With the following scissor operator: Oitalicscissor=Σ(μν)true{true(U2true)∣μ〉〈μ∣−true(U2true)∣ν〉〈ν∣true}, |μ〉 (| ν 〉) being the empty (occupied) molecular orbitals of the isolated molecule (with the actual geometry of the molecule on the surface), we open the LDA-energy gap, E g LDA , to E g LDA +U, where U is fixed to yield the experimental energy gap of 3.9 eV (see below).…”

“…As mentioned above, the organic/oxide interface electronic properties are analyzed introducing some corrections in our local-orbital DFT calculations. These corrections are required due to the following limitations of standard DFT functionals (e.g., LDA, GGA): (a) the Kohn–Sham energy levels yield transport gaps for the organic molecules that are usually too small; ,, and (b) the initial relative level alignment between the oxide and the organic materials is not correctly described even in well-converged LDA (or GGA) calculations. − Following up previous publications − we introduced two operators to amend these problems. With the following scissor operator with |μ⟩(|ν⟩) being the empty (occupied) molecular orbitals of the isolated molecule (with the actual geometry of the molecule on the surface), we open the LDA-energy gap, E g LDA , to E g LDA +U, where U is fixed to yield the experimental energy gap of 3.9 eV (see below).…”

Quantitative molecular orbital energies within a G0W0 approximation

“…In this article, building on prior work [10,[12][13][14][15][16][17][18][19][20], we explore the extent to which we may obtain accurate IPs and electron affinities (EAs) of gas-phase molecules using a G 0 W 0 approximation. While there are numerous studies benchmarking the GW approximation against transport gaps in bulk inorganic solids [11,[21][22][23][24], similar works for isolated molecular systems are less common, and while all works exhibit marked improvement over standard DFT approaches, there is some quantitative disagreement (see e.g., [10,[12][13][14][15][16][17][18][19]25]). For example, for gas-phase molecules, using an atom-centered basis set, it has been found that self-consistency in either the GW eigenvalues [12][13][14] or in both the eigenvalues and eigenvectors [15] is essential for obtaining good agreement of computed molecular IP and EA with experiment.…”

Ein molekularer Siliciumcluster mit einem “nackten” Gerüstatom

“…[2] Tatsächlich hängen die optischen Eigenschaften bestimmter Silicium-Materialien zum großen Teil vom Vorhandensein kleiner bis mittlerer teilhydrierter Cluster innerhalb der umgebenden Siliciummatrix ab -so wurde die in porösem Silicium beobachtete Photolumineszenz der Anregung derartiger Cluster zugeschrieben. [3,4] Die Schwierigkeiten bei der strukturellen Charakterisierung dieser Verbindungen würden durch die Synthese diskreter molekularer Derivate umgangen. Die Fortschritte bei der Synthese molekularer Germanium-und Zinncluster mit "nackten", d. h. unsubstituierten Gerüstatomen wurden jüngst zusammengefasst.…”