Reduced coupling of water molecules near the surface of reverse micelles

We report on vibrational dynamics of water near the surface of AOT reverse micelles studied by narrow-band excitation, mid-IR pump–probe spectroscopy. Evidence of OH-stretch frequency splitting into the symmetric and asymmetric modes is clearly observed for the interfacial H2O molecules. The polarization memory of interfacial waters is preserved over an exceptionally extended >10 ps timescale which is a factor of 100 longer than in bulk water. These observations point towards negligibly small intermolecular vibrational coupling between the water molecules as well as strongly reduced water rotational mobility within the interfacial water layer.

Investigation of the Ga-rich GaAs(001) Surface Reconstructions Stability and Interaction with Halogens

Atomic and electronic structures for a number of GaAs(001) surface geometries were studied within the density functional theory in order to re-examine the energy stability of surface reconstructions in the Ga-rich limit. It was shown that among geometries with (42) symmetry so-called ζ-model is most stable but the energetically favored Ga-rich (24) reconstructions are stabilized by dimerized Ga and As atoms. Our calculations predict the coexistence of (24) and (44) reconstructions on GaAs(001) in the Ga-rich limit. Comparative study of the halogens (F, Cl, I) adsorption on the -GaAs(001)-(42) surface were performed. The energetically preferable positions for all considered halogens are found on-top sites above dimerized and nondimerized Ga atoms. The electronic properties of the semiconductor surface and its change upon halogen adsorption are discussed. It was shown that the interaction of halogen with the Ga dimerized at-oms leads to the weakening of the chemical bonds between surface atoms that determines the initial stage of surface etching. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3531

Influence of Fluorine and Oxygen Adsorption on the Electronic Properties of the InAs(111)A-(2*2) Surface

Atomic and electronic structures of the reconstructed InAs(111)A-(2*2) surface are studied within den-sity functional theory. The most stable adsorption positions of oxygen and fluorine on the surface are de-termined. Our calculations show that oxygen adsorption leads to appearance of electronic states in band gap and the structure of these surface states strongly depends on adsorption geometry. An increase of oxy-gen concentration and its coadsorption with fluorine leads to substantial structural changes in the surface and subsurface layers due to adsorbate penetration into semiconductor. Evolution of the electronic struc-ture upon oxygen and fluorine adsorption on the reconstructed InAs(111)A-(2*2) surface in dependence on adsorbate geometry is analyzed. It is shown that surface states induced by oxygen adsorption can be par-tially removed by fluorine, when it forms bonds with the surface indium atoms. The formation of the indi-um–fluorine or indium–oxygen bonds proceeds due to charge transfer from arsenic atoms to indium ones in the surface layers. The microscopic mechanism of fluorine influence on the interface states at InAs–oxides interface is suggested. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3529

Halogen adsorption at an As-stabilized β2-GaAs (001)-(2×4) surface

Halogen (F, Cl, Br, and I) adsorption at an As-stabilized GaAs (001) surface with the β2–(2 × 4) reconstruction is studied using the plane-wave projected-augmented wave method. The effect of halogens on the structural and electronic characteristics of the semiconductor surface is analyzed. The T2′ site at the missing row edge is shown to be the energetically most favorable for the adsorption of F, Cl, and Br, whereas I prefers the H3 site between adjacent arsenic dimers in the third layer from the surface. Ga-halogen bond formation suggests that charge is transferred via the depletion of occupied orbitals of the As-dimer surface atoms, which leads to the weakening of Ga–As bonds in the substrate. The weakening of bonds between substrate-surface atoms due to the interaction of halogens with the surface is estimated

Simultaneous enhancement in open circuit voltage and short circuit current of hybrid organic-inorganic photovoltaics by inorganic interfacial modification

Here, we investigate the model poly(3-hexathiophene)/ZnO system and show that by introducing a caesium carbonate interlayer, a simultaneous increase in all photovoltaic parameters can be achieved.We kindly acknowledge Prof. Uwe Bunz and Prof. Annemarie Pucci for access to device fabrication facilities and AFM measurements, respectively. P.E.H. thanks the Excellence Initiative for Funding. A.A.B. is a Royal Society University Research Fellow.This is the author accepted manuscript. The final version is available from The Royal Society of Chemistry via http://dx.doi.org/10.1039/C5TC03206

Control and supervision over penitentiary systems in France and the USA

This article is devoted to the study of the institution of control and supervision over penitentiary systems in France and the USA. It is noted that this institution, especially in the European penitentiary systems, in general, is similar to the institution of control and supervision over institutions and bodies implementing criminal penalties in Russia. Firstly, this is due to belonging to two most recognized legal systems in the world - Anglo-Saxon (USA) and Romano-German (Russia, France). Secondly, this is due to using the international law in their domestic legal systems, although the forms of implementing the international norms have their own peculiarities. Thus, foreign specialists in the field of international law singled out two models in the mechanism of implementing the international legal norms within the national legal system - transformational (implementational) and adoptive (incorporative) (Vanek, 1949; Brownlie, 2003), which were used in the countries of the Anglo-Saxon legal system. A distinctive feature of the US legal system is the priority of US national legislation over the international treaties involving the USA. Thirdly, the relative uniformity of control and supervision over the penitentiary systems of France and the USA is due to the sufficient identity of the systems of criminal penalties and types of correctional facilities. Punishment in the form of deprivation of liberty forms the backbone of the system in almost all civilized countries of the world, and prisons are the eternal companions of almost any state in the world. Fourthly, the effectiveness of the institution of control and supervision over penitentiary system depends to a large extent on the institutional model of penal system existing in a given country both abroad and in Russia. The effectiveness of the institution of control and supervision over penitentiary system makes impact on the effectiveness of penitentiary system itself. The indicators of the system effectiveness are represented by the level of post-penitentiary relapse, that is, the number of persons having committed crimes after serving their sentence. The statistics, unfortunately, indicate that more than half of former prisoners commit the crimes again in the USA (Bykov, 2015), and the post-penitentiary relapse is up to 60% in the prisons in France (Utkin, 2016). From our point of view, the efficiency of penitentiary system is influenced by the institution of pardon, which is stipulated by French law (Articles 133-7, 133-8 of the Criminal Code of France) (Bakulina, Bakulin, 2015) and the US law. As a rule, pardons commit secondary offenses fewer times than just those released or amnestied

Ultrafast Spectroscopy with Photocurrent Detection: Watching Excitonic Optoelectronic Systems at Work.

While ultrafast spectroscopy with photocurrent detection was almost unknown before 2012, in the last 3 years, a number of research groups from different fields have independently developed ultrafast electric probe approaches and reported promising pilot studies. Here, we discuss these recent advances and provide our perspective on how photocurrent detection successfully overcomes many limitations of all-optical methods, which makes it a technique of choice when device photophysics is concerned. We also highlight compelling existing problems and research questions and suggest ways for further development, outlining the potential breakthroughs to be expected in the near future using photocurrent ultrafast optical probes.A.A.B. is currently a Royal Society University Research Fellow. A.A.B. also acknowledges a VENI grant from the NWO. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No. 639750). C.S. acknowledges funding from the Natural Science and Engineering Research Council of Canada, the Fonds de recherche du Québec–nature et technologies, the Canada Research Chair in Organic Semiconductor Materials, and the Université de Montréal Research Chair. C.S. and E.V. acknowledge collaboration with Sachetan Tuladhar, Michelle Vezie, Sheridan Few, Jenny Nelson, Hao Li, and Eric Bittner. Finally, C.S. and E.V. acknowledge essential discussions with Andy Marcus and Julia Widom for the implementation of the two-dimensional spectroscopy apparatus.This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/acs.jpclett.5b0195

Ab-initio study of cation-rich InP(001) and GaP(001) surface reconstructions and iodine adsorption

Atomic and electronic structures for a number of InP and GaP (001) surface geometries were studied within the density functional theory (DFT) in order to reexamine the energy stability of surface reconstructions in the cation-rich limit. It is shown that in both cases the mixed dimer (2×4) reconstruction is the energetically favored in the cation rich limit. The ζ(4×2) reconstruction has the lowest surface energy among considered (4×2) surface structures. Comparative theoretical study of iodine adsorption on the semiconductor surface with ζ(4×2) and mixed dimer (2×4) structures was performed. It was shown that iodine prefers to be bonded with dimerized cation atoms irrespective on the surface reconstruction