In-gap state generated by La-on-Sr substitutional defects within the bulk of SrTiO₃

Abstract

Free energy perturbation (FEP) approaches with stratification see widespread and increasing use in computational studies of biologically relevant molecules. However, when the molecular system are characterized by a complex conformational free energy landscape, the assessment of convergence remains a concern for many practitioners. The sampling problem in FEP has been authoritatively addressed in a recent perspective paper [ D. Mobley, J. Comput. Aided Mol. Des., 26, 93 2012 ], incisively entitled "Let's get honest about sampling". Here, I return on the issue of sampling in the determination of the octanol-water partition coefficient for a synthetic precursor of Kinase inhibitors that has been included in the recent extension of the SAMPL6 blind challenge of LogP coefficients. I will show, that even for this simple compound, whose conformational space is essentially dictated by two sp 3 rotable bonds connecting rigid planar units, canonical sampling using standard techniques can be surprisingly hard to achieve. I will also show how the conformational sampling problem can be effectively bypassed using unidirectional and bidirectional non equilibrium work methods, reliably recovering the solvation energy with minimal methodological uncertainty. the simulation and exploiting, in an inexpensive post-processing stage, powerful bidirectional maximum likelihood estimators like the so-called Bennett Acceptance Ratio (BAR). 9Stratification is costly since one has to perform n equilibrium J o u r n a l N a me , [ y e a r ] , [ v o l . ] , 1-10 | 1

Elaboration of near‐valence band defect states leading deterioration of ambipolar operation in SnO thin‐film transistors

“…According to previous experimental and theoretical studies, lattice defects and distortions are considered the origin of the near-VB defect states of oxides. [26][27][28][29][30] Since surface and/or bulk electronic states of oxides are strongly correlated with the interfacial structure, [31][32][33][34] we prepared two types of SnO TFTs on (001)-oriented yttria-stabilized zirconia (YSZ) singlecrystal substrates with different surface morphologies. We observed that the optimum growth temperature of SnO films was different depending on the surface conditions of YSZ substrates; further, the operation mode changed between the ambipolar and the p-channel for SnO-TFTs.…”

Oxygen Vacancies in Strontium Titanate: a DFT+DMFT study

“…Interestingly, the resulting properties can be quite sensitive to the specific type of doping. [12][13][14][15][16][17][18][19][20][21][22] Regarding oxygen-vacancy doping in SrTiO 3 , perhaps the most pressing open question is the nature of the introduced charge, with different experimental measurements leading to apparently contradictory conclusions. On one hand, it is known that even very low concentrations of oxygen vacancies cause metallicity, with transport measurements indicating an increase in carrier density with increasing oxygen vacancy concentration.…”

Characteristic Electronic Structure of SnO Film Showing High Hole Mobility

“…Angle-resolved photoemission spectroscopy (ARPES) is a powerful and unique technique for investigating the electronic structure of materials experimentally based on the well-known relationship between the kinetic energy and emission angle of photoelectron. 21,22 Owing to its surface sensitivity, a clean and well-defined surface is indispensable for observing these intrinsic electronic structures of materials. Sputtering and/or annealing processes have conventionally been applied to prepare such surfaces.…”

“…The uppermost valence band is clearly observed for LH polarization but not for LV polarization. On the basis of dipole transition selection rules for optical transitions, 21,22 the photoelectrons are only detected when the initial state is symmetric and antisymmetric, with respect to the symmetry operation, to the detection (mirror) plane for LH and LV polarizations, respectively. Because the point group along the symmetric Γ−X (Γ−Μ) line is C 2v , the bands with Γ 1 and Γ 2 (Γ 1 and Γ 4 ) symmetries should be observed for LH polarization, whereas the bands with Γ 3 and Γ 4 (Γ 2 and Γ 3 ) symmetries should be observed for LV polarization.…”

“…Angle-resolved photoemission spectroscopy (ARPES) is a powerful and unique technique for investigating the electronic structure of materials experimentally based on the well-known relationship between the kinetic energy and emission angle of photoelectron. , Owing to its surface sensitivity, a clean and well-defined surface is indispensable for observing these intrinsic electronic structures of materials. Sputtering and/or annealing processes have conventionally been applied to prepare such surfaces. − However, these processes cause compositional deviations from the original and the observed ARPES spectra do not reflect the intrinsic electronic structure. , To overcome this drawback, a compact in vacuo transferring system has been developed that enables the transfer of thin films, prepared by the thin-film deposition equipment, to the ARPES apparatus without exposing them to the atmosphere …”