Determination of the mean inner potential in III–V semiconductors, Si and Ge by density functional theory and electron holography

Theoretical and experimental factors affecting measurements of semiconductor mean inner potentials

“…The fact that the present DFT values are close to those in Ref. [3] (also reproduced in Table 3) provides confidence in the applicability of the GPAW simulator for calculations of V 0 for a wide range of materials. Table 3.…”

“…The calculation volume contained the material of interest and a region with no material, as shown in Fig. 1 and also used by Kruse et al [3]. The Hartree potential V H was determined from the valence electrons, screened core electrons and nuclei for region B marked in Fig.…”

“…V 0 calculated for different semiconductors with (110) surfaces using the present density functional theory (DFT) calculations, compared with values reproduced from the DFT calculations of Ref. [3] and obtained using neutral atom electron scattering factors (V fel ) taken from Ref. [6].…”

Quantitative Agreement between Electron-Optical Phase Images ofWSe2and Simulations Based on Electrostatic Potentials that Include Bonding Effects

“…As the effects of bonding are neglected, the results of simulations based on this approximation overestimate the mean phase of the electron wavefunction when compared to experimental measurements [5]. The accuracy of calculated mean electron phases has been shown to improve when using density functional theory (DFT) for the calculation of electrostatic potentials to take bonding effects into account [6,7]. However, to the best of our knowledge, no comparison between the DFTcalculated atomic-resolution spatial distribution of the electron phase and high-resolution electron holography experiments has been performed.…”

“…Furthermore, the DFT method yields the lowest potentials, whereas the IAA and IDFT results exceed the DFT values by approximately 9% and 6%, respectively. The difference between the IDFT and IAA values can be explained by the use of a different computational technique: the scattering factors that were used as input for IAA electrostatic potentials were obtained from relativistic Hartree-Fock calculations [7]. In order to relate differences between the DFT and IDFT calculations to a spatial change in electron den- is the bulk mean inner potential of WSe2 [29].…”