“…The fact that the damping shift is substantially reduced by accounting for inhomogeneous broadening might explain why the energy of graphite and diamond plasmons were reproduced [6] even without correcting the measured energies for the damping shift.…”
Section: Discussionmentioning
confidence: 99%
“…[5,6] To evaluate the latter, the mean gap (Penn gap) was taken into account, though the HOPG energy gap varies from zero to more than 10 eV in the k-space. Here we are going to consider a first approximation to take such a gap distribution into account.…”
Section: Plasmon Peak Width: the Case Of Hopgmentioning
confidence: 99%
“…Assuming the same excitation energy π ↔σ for π → σ * and σ → π * transitions, approximate solutions to these equations are: [6] …”
Section: Plasmon Peak Width: the Case Of Hopgmentioning
confidence: 99%
“…In this figure, we approximate each of the σ , π , σ * , π * DOS by a Gaussian curve. One should note that describing the DOS by Gaussian distributions rather than by δ-functions, as done before, [5,6] is only a first approximation which can be used to get the minimum value of inhomogeneous broadening. In some cases, as for the σ * DOS, the widths are clearly underestimated.…”
Section: Plasmon Peak Width: the Case Of Hopgmentioning
confidence: 99%
“…In this respect, our basis is a phenomenological approach we recently developed for the analysis of EELS spectra from carbon materials. [5,6] The present paper is an extension of this previous work, in which the width of plasmon peaks had not been taken into account. Highly oriented pyrolytic graphite (HOPG) is taken as a case study.…”
In addition to the damping effect on plasmon peak broadening in reflection electron energy loss spectroscopy (REELS), the effect of inhomogeneous broadening is considered. The analysis of experimental data from highly oriented pyrolytic graphite (HOPG) shows that the contribution of inhomogeneous broadening is of the same order as the contribution associated with damping. In other words, the width of plasmon peaks cannot be ascribed only to damping, which is just one among several other contributions in this respect. At variance with other broadening contributions, however, damping is responsible not only for the width of plasmon peaks but also for their energy. For this reason, by showing that accounting for inhomogeneous broadening leads to decrease of the damping parameter, we also show that the plasmon peak-shift associated with damping is less than one could expect otherwise.
“…The fact that the damping shift is substantially reduced by accounting for inhomogeneous broadening might explain why the energy of graphite and diamond plasmons were reproduced [6] even without correcting the measured energies for the damping shift.…”
Section: Discussionmentioning
confidence: 99%
“…[5,6] To evaluate the latter, the mean gap (Penn gap) was taken into account, though the HOPG energy gap varies from zero to more than 10 eV in the k-space. Here we are going to consider a first approximation to take such a gap distribution into account.…”
Section: Plasmon Peak Width: the Case Of Hopgmentioning
confidence: 99%
“…Assuming the same excitation energy π ↔σ for π → σ * and σ → π * transitions, approximate solutions to these equations are: [6] …”
Section: Plasmon Peak Width: the Case Of Hopgmentioning
confidence: 99%
“…In this figure, we approximate each of the σ , π , σ * , π * DOS by a Gaussian curve. One should note that describing the DOS by Gaussian distributions rather than by δ-functions, as done before, [5,6] is only a first approximation which can be used to get the minimum value of inhomogeneous broadening. In some cases, as for the σ * DOS, the widths are clearly underestimated.…”
Section: Plasmon Peak Width: the Case Of Hopgmentioning
confidence: 99%
“…In this respect, our basis is a phenomenological approach we recently developed for the analysis of EELS spectra from carbon materials. [5,6] The present paper is an extension of this previous work, in which the width of plasmon peaks had not been taken into account. Highly oriented pyrolytic graphite (HOPG) is taken as a case study.…”
In addition to the damping effect on plasmon peak broadening in reflection electron energy loss spectroscopy (REELS), the effect of inhomogeneous broadening is considered. The analysis of experimental data from highly oriented pyrolytic graphite (HOPG) shows that the contribution of inhomogeneous broadening is of the same order as the contribution associated with damping. In other words, the width of plasmon peaks cannot be ascribed only to damping, which is just one among several other contributions in this respect. At variance with other broadening contributions, however, damping is responsible not only for the width of plasmon peaks but also for their energy. For this reason, by showing that accounting for inhomogeneous broadening leads to decrease of the damping parameter, we also show that the plasmon peak-shift associated with damping is less than one could expect otherwise.
In this work we use density functional theory (DFT) to investigate the influence of semi-local exchange and correlation effects on the electronic and optical properties of zinc oxide. We find that the inclusion of such effects using the Tran-Blaha modified Becke-Johnson potential yields an excellent description of the electronic structure of this material giving energy band gap which is systematically larger than the one obtained with standard local functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significantly reduced at a computational low cost. We also calculated the dielectric functions of ZnO and find a violet shift to the absorption edge which is in good agreement with experimental results. * jailton almeida@hotmail.comRecently proposed Tran-Blaha modified version of the Becke-Johnson potential (TB-mBJ) [20] has proved to be a successful method for accurate band gaps of semiconductors and insulators [21][22][23][24][25]. Furthermore, it has a computational cost as the LDA or GGA. For ZnO, it has been shown to lead to band gaps close to the experimental values [8,24,25].In this work, we use the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential [20] to investigate the electronic structure and optical response of ZnO. We found that TB-mBJ potential greatly improves the description of the electronic structure of ZnO compared to GGA, but still has several drawbacks with respect to GW calculations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.