Density Functional Study of the Structures of Lead Sulfide Clusters (PbS)n (n = 1−9)

Zeng, Hongxia; Schelly, Z. A.; Ueno‐Noto, Kaori

doi:10.1021/jp040457l

Cited by 36 publications

(35 citation statements)

References 29 publications

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“…2(b) that the TDOS of PbS nanocluster begins to discrete because of the QCE. The oscillates of HOMO-LUMO gaps suggest that the ultraviolet (UV) absorption band alternating red shifts followed by blue shifts with the nanoclusters size increasing, which is in much better agreement with the results using Gaussian 03 DFT to study PbS nanoclusters [13,21]. However, the values differs from DFT calculations results because of different calculation method, basis set and accuracy grade, and so on.…”

Section: Properties Of Pbs Nanoclusterssupporting

confidence: 78%

Physical characteristics and optical properties of PbS nanoclusters: DFT simulation and experimental study

et al. 2015

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The physical characteristics and optical properties of PbS nanoclusters are investigated by using density functional theory (DFT) of first-principles. Microstructure models of (PbS) n (n=1-9) nanoclusters and bulk materials are built on Materials Studio platform, and its energy band structures, highest occupied molecular orbital-lowest unoccupied molecular orbital gap (HOMO-LUMO gap), density of state (DOS), and optical properties are calculated, respectively. Compared to PbS bulk materials, PbS nanoclusters show a discrete energy gap as well as the DOS, because of the quantum confinement effect. It is interesting that the HOMO-LUMO gap of (PbS) n (n=1-9) shows oscillates with the increasing of the n number. However, when its size is large enough, the HOMO-LUMO gap is gradually decrease with the increasing of size (>27 atoms). And, the HOMO-LUMO gap of PbS nanoclusters of different sizes is range from 2.575 to 0.58 eV, which covers the low loss communication band of optical communication. In addition, PbS nanomaterials (NMs) with small size are synthesized by using oleylamine as ligands. Sizes of PbS NMs can be accurately controlled through control of the reaction time as well as the growth temperature. The photoluminescence (PL) spectra show strong size dependence, which is large red shift with increasing size of the NMs. This trend is basically in agreement with the theoretical calculation above. Moreover, transmission electron microscopy (TEM) further reveals the morphology of PbS NMs. PbS NMs can be used in optical fiber amplifiers and fiber lasers because of its unique optical properties in optical communication bands.

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Section: Properties Of Pbs Nanoclusterssupporting

confidence: 78%

Physical characteristics and optical properties of PbS nanoclusters: DFT simulation and experimental study

et al. 2015

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“…17 We used the gradient-corrected PW91PW91 functional, 18 while the compact effective potentials (CEPs) due to Stevens et al 19 (SBKJC) and 6-311 + G* basis sets were used for lead and sulfur atoms, respectively. In the two previously reported DFT-based studies on (PbS) n clusters, 13,14 the hybrid DFT functional, Becke's three parameter hybrid exchange functional with Lee, Yang, and Parr correlation functional (B3LYP), 20,21 was employed. In order to verify the accuracy of our density functional as well as the basis set (SBKJC) for the lead atoms, we calculated the adiabatic detachment energy (ADE) and vertical detachment energy (VDE) of the Pb 6 S 6 − cluster using both B3LYP and PW91PW91 functionals, along with two different basis sets for Pb, namely, the Stuttgart/Dresden (SDD) basis set 22 and SBKJC.…”

Section: B Computational Methodsmentioning

confidence: 99%

“…Those calculations include two DFT studies which investigated the stability and optical properties of neutral (PbS) n clusters. 13,14 To our knowledge, neither experimental nor theoretical studies of negatively charged lead sulfide clusters exist in literature. In order to gain a better understanding of the structural evolution and electronic structure of small lead sulfide clusters, we conducted a synergetic experimental and computational study of their anions and corresponding neutrals, (PbS) n − and (PbS) n , respectively.…”

Section: Introductionmentioning

confidence: 99%

Structural evolution and stabilities of neutral and anionic clusters of lead sulfide: Joint anion photoelectron and computational studies

Koirala

Kiran

Kandalam

et al. 2011

The Journal of Chemical Physics

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The geometric and electronic structures of both neutral and negatively charged lead sulfide clusters, (PbS)(n)/(PbS)(n)(-) (n = 2-10) were investigated in a combined anion photoelectron spectroscopy and computational study. Photoelectron spectra provided vertical detachment energies (VDEs) for the cluster anions and estimates of electron affinities (EA) for their neutral cluster counterparts, revealing a pattern of alternating EA and VDE values in which even n clusters exhibited lower EA and VDE values than odd n clusters up until n = 8. Computations found neutral lead sulfide clusters with even n to be thermodynamically more stable than their immediate (odd n) neighbors, with a consistent pattern also being found in their HOMO-LUMO gaps. Analysis of neutral cluster dissociation energies found the Pb(4)S(4) cube to be the preferred product of the queried fragmentation processes, consistent with our finding that the lead sulfide tetramer exhibits enhanced stability; it is a magic number species. Beyond n = 10, computational studies showed that neutral (PbS)(n) clusters in the size range, n = 11-15, prefer two-dimensional stacking of face-sharing lead sulfide cubical units, where lead and sulfur atoms possess a maximum of five-fold coordination. The preference for six-fold coordination, which is observed in the bulk, was not observed at these cluster sizes. Taken together, the results show a preference for the formation of slightly distorted, fused cuboids among small lead sulfide clusters.

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“…Among various semiconducting nanomaterials, lead salts, such as PbS and PbSe, show some of the most unique electronic and transport properties [83,[114][115][116][117]. Their conduction and valence bands are more symmetric than in other semiconductor materials, such as CdSe, potentially rendering Auger relaxation processes inefficient [118], and making it easier to study the electron-phonon relaxation pathway.…”

Section: Relaxation In Semiconductor Nanocrystalsmentioning

confidence: 99%

Time-domain ab initio modeling of excitation dynamics in quantum dots

Neukirch¹,

Hyeon‐Deuk²,

Prezhdo³

2014

Coordination Chemistry Reviews

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The review discusses the results of ab initio time-dependent density functional theory and nonadiabatic molecular dynamics simulations of photoinduced dynamics of charges, excitons, plasmons, and phonons in semiconductor and metallic quantum dots (QD). The simulations create an explicit timedomain representation of the excited-state processes, including elastic and inelastic electron-phonon scattering, multiple exciton generation, fission, and recombination. These nonequilibrium phenomena control the optical and electronic properties of QDs. Our approach can account for QD size and shape, as well as chemical details of QD structure, such as dopants, defects, core/shell regions, surface ligands, and unsaturated bonds. Each of these variations significantly alters the properties of photoexcited QDs.The insights reported in this review provide a comprehensive understanding of the excited-state dynamics in QDs and suggest new ways of controlling the photo-induced processes. The design principles that follow, guide development of photovoltaic cells, electronic and spintronic devices, biological labels, and other systems rooted in the unique physical and chemical properties of nanoscale materials.

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Density Functional Study of the Structures of Lead Sulfide Clusters (PbS)_n (n = 1−9)

Cited by 36 publications

References 29 publications

Physical characteristics and optical properties of PbS nanoclusters: DFT simulation and experimental study

Physical characteristics and optical properties of PbS nanoclusters: DFT simulation and experimental study

Structural evolution and stabilities of neutral and anionic clusters of lead sulfide: Joint anion photoelectron and computational studies

Time-domain ab initio modeling of excitation dynamics in quantum dots

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