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abstract: We have studied experimentally and theoretically the optical orientation and spin dependent Shockley Read Hall recombination in a semiconductor in a magnetic field at an arbitrary angle a between the field and circularly polarized exciting beam. The experiments are performed at room temperature in GaAs1 xNx alloys where deep paramagnetic centers are responsible for the spin dependent recombination. The observed magnetic field dependences of the circular polarization r(B) and intensity J(B) of photoluminescence can be approximately presented as a superposition of two Lorentzian contours, normal and inverted, with their half widths differing by an order of magnitude. The normal, narrow, Lorentzian contour is associated with depolarization of the transverse (to the field) component of spin polarization of the localized electrons, whereas the inverted, broad, Lorentzian is due to suppression of the hyperfine interaction of the localized electron with the own nucleus of the defect. The ratio between the height of one Lorentzian and depth of the other is governed by the field tilt angle a. In contrast to the hyperfine interaction of a shallow donor bound electron with a large number of nuclei of the crystal lattice, in the optical orientation of the electron nuclear system under study no additional narrow peak appears in the oblique field. This result demonstrates that in the GaAsN alloys the hyperfine interaction of the localized electron with the single nucleus of the paramagnetic center remains strong even at room temperature. For a theoretical description of the experiment, we have extended the theory of spin dependent recombination via deep paramagnetic centers with the nuclear angular momentum I 1/2 developed previously for the particular case of the longitudinal field. The calculated curves r(B) J(B) agree with the approximate description of the experimental dependences as a sum of two Lorentzians, and an additional narrow shifted peak does not appear in the computation as well.
author_names: E L Ivchenko

Leonid Bakaleinikov

Mikhail Mikhailovich Afanasiev

Vladimir K Kalevich
title: Spin dependent recombination in GaAs1 xNx alloys at oblique magnetic field
year: 2016

abstract: A new series of oxynitrides LaVO3 xNx (0 x 0.9) has been synthesized and their electrical and magnetic properties studied. Contrary to the oxides involving the mixed valence VIII VIV, no semiconductor metal transition is observed and all the compounds remain p type semiconductors.
author_names: P Antoine

R Assabaa

P L'haridon

Roger G Marchand

Yves Laurent

Claude Michel

Bernard Raveau
title: Transport properties of the new perovskite type LaVO3=xNx Oxynitrides
year: 1989

abstract: Magnetophotoluminescence measurements show that the electron effective mass and the exciton radius in hydrogen irradiated GaAs 1 x N x vary continuously as a function of the hydrogen dose until they recover the values ofN free GaAs. First principles calculations account for the experimental findings through the formation of a specific N dihydrogen complex, which leads to the removal of the electron localization caused by N incorporation into GaAs.
author_names: Antonio Polimeni

G Baldasarri Hoger von Hogersthal

Francesco Masia

Andrea Frova

M Capizzi

Simone Sanna

Vincenzo Fiorentini

Peter J Klar

Wolfgang Stolz
title: Tunable variation of the electron effective mass and exciton radius in hydrogenated GaAs1 xNx
year: 2004

abstract: The electron effective mass, m* e and exciton radius, r e x c have been derived in GaAs 1 x N x (x 0.2% by magneto photoluminescence measurements. With increasing nitrogen concentration, m* e and r e x c undergo a rapid increase and squeezing, respectively, already for x 0.1% Furthermore, in a hydrogen irradiated GaAs 1 x N x sample, the band gap widening induced by H maps on a profound modification of the conduction band. m* e (r e x c decreases (increases) with increasing H dose, until the GaAs value is obtained. First principle calculations show that the formation of a specific N H 2 dihydrogen complex leads to the removal of the electron localization caused by N incorporation in GaAs.
author_names: Antonio Polimeni

Francesco Masia

Giorgio Baldassarri Hoger von Hogersthal

Andrea Frova

M Capizzi

Simone Sanna

Vincenzo Fiorentini

Peter J Klar

Wolfgang Stolz
title: Tuning of the electron effective mass and exciton wavefunction size in GaAs1 xNx
year: 2004

abstract: The chemical processes of formation and decomposition of narrow gap nitrides InN and GaAs1 xNx under ion bombardment have been investigated by Auger electron spectroscopy. It is shown that, due to chemical instability, a large fraction of InN decomposes with formation of metal clusters under ion bombardment. It is established that bombardment of GaAs with a beam of N2+ and Ar+ ions makes it possible to obtain a chemically homogeneous GaAs1 xNx solid solution with a high nitrogen content (x 0.1) whereas implantation of only N2+ ions leads to the formation of a mixture of GaN, GaAsN, and GaAs phases. It is concluded that secondary ion cascades, induced by heavy ions, stimulate nitridation reaction, homogenize the spatial atomic distribution, and shift the dynamic equilibrium to the formation of a single phase solution.
author_names: V M Mikushkin

V V Bryzgalov

Yu S Gordeev

Valery Yu Davydov
title: Formation and decomposition of nitrides under ion bombardment
year: 2008

abstract: The modification of GaAs with a 2500 eV beam containing N2+ and Ar+ ions is examined with Auger electron spectroscopy. Most implanted nitrogen atoms are found to react with the matrix, substituting arsenic atoms to produce a several nanometer thick layer of the single phase GaAs1 xNx (x=6% solid solution. The GaN phase is absent. Displaced arsenic atoms and nitrogen atoms unreacted with the matrix are present in the layer and on its surface. The former segregate, whereas the latter form molecules.
author_names: Yu S Gordeev

V V Bryzgalov

Boris Makarenko

V M Mikushkin

Samuil G Konnikov

Pavel N Brunkov

V M Ustinov

Alexey E Zhukov
title: Modification of GaAs by medium energy N2+ ions
year: 2003

abstract: We present a study of the optical properties of double quantum wells of In0.3Ga0.7As1 xNx/GaAs. The nitrogen composition, x, lies between 2 10 3 and 9.5 10 3. Temperature dependence of time integrated photoluminescence (PL) and time resolved PL have been investigated. The temperature dependences of the PL energy and the linewidth are correlated, and they show that the carriers are localised at low temperature. Consistently the energy dependence of decay time across the PL line is analysed in terms of mobility edge. The carrier localisation at low temperature is due to alloy disorder in the wells which induces potential fluctuations. The PL linewidth increases with temperature. This linewidth is also strongly increased by the increase of the N composition. We attribute this behaviour to an enhanced coupling of the carriers with LO phonons. We deduce from these results that N incorporation increases the polar character of the III V compound.
author_names: Romuald Intartaglia

T Taliercio

Pierre Valvin

Guilhem Almuneau

Pierre Lefebvre

Thierry Guillet

Thierry Bretagnon

Bernard Gil
title: Longitudinal optical phonon broadening due to nitrogen atom incorporation in InGaAsN/GaAs quantum wells
year: 2005

abstract: Results are given for a study of the TiLa, TiLi, and NKa x ray emission bands in TiC1 xNx compounds (x from 0.038 to 0.930) These spectra served as the basis for a discussion of the structure of the energy bands of TiC TiN solid solutions and the evaluation of the validity of various theoretical models. The possibility of determining the composition of solid carbonitride alloys by analysis of the intensity of the x ray emission bands was examined.
author_names: Artem V Ezhov

V M Cherkashenko

B V Mitrofanov

Ernst Z Kurmaev
title: Ultrasoft x ray emission spectra of the components in complete titanium nitrides
year: 1989

abstract: Here SnO2/LaFeO3 XNX composite was fabricated using a wet chemical method and was applied to pollutants degradation and gas sensing for the first time. The composite exhibits high performance for photocatalytic degradation of Rhodamine B (RhB) dye and selectivity sensing of various gases. On the basis of the completed experiments, the improved RhB degradation and selective gas sensing performance resulted from the extended optical absorption via N2 incorporated surface states and enhanced charge separation via coupling SnO2. Using the scavengers trapping experiments, the superoxide radical (O2* was investigated as the major scavenger involved in the degradation of RhB over SnO2/LaFeO3 XNX composite. In this paper, the probable reaction steps involved in the RhB dye degradation over SnO2/LaFeO3 XNX composite are proposed. This work will provide reasonable strategies to fabricate LaFeO3 based proficient and stable catalysts for environmental purification. In addition, the result of the selectivity of gas performance is also presented.
author_names: Xi-tao Yin

Davoud Dastan

Fa-yu Wu

Jianshu Li
title: Facile Synthesis of SnO2/LaFeO3 XNX Composite: Photocatalytic Activity and Gas Sensing Performance
venue: Nanomaterials
year: 2019

abstract: Graphitic carbon nitrides (CNs) are potential candidate materials for the electro catalytic industry due to their unique physical and chemical properties. However, to date, a full understanding of the electro catalytic properties of CNs is still lacking. Herein, by using density functional theory calculations, we systematically investigate the catalytic performances in the hydrogen evolution reaction (HER) oxygen evolution reaction (OER) N2 reduction reaction (NRR) and CO2 reduction reaction (CO2RR) of monolayer graphitic carbon nitrides (C1 xNx) C3N (x 1/4) C2N (x 1/3) and g C3N4 (x 4/7) We also evaluated the NRR activity of B doped C1 xNx, and the CO2RR activity of Cu and Pd modified C1 xNx. The cohesive energy and ab initio molecular dynamics (AIMD) results show that C3N, C2N, and g C3N4 are stable at room temperature. The C3N C1 site is predicted to deliver the best HER catalytic performance with a reaction Gibbs free energy (DGH* of 0.03 eV (close to the ideal value (0 eV) Among the studied C1 xNx materials, the C3N C2 site is predicted to possess a favorable eOER of 0.82 V for OER. Pure C3N, C2N, and g C3N4 are not suitable for NRR and CO2RR. Due to the strong hybridization between the N 2p orbital and the B 2p orbital, the NRR performances of B doped BN C2N, BN C3N, and BN g C3N4 are greatly enhanced, with corresponding overpotential eNRR of 0.57 V, 0.70 V, and 0.72 V, respectively. The transition metals Cu and Pd can enhance the CO2RR activity of C3N, C2N, and g C3N4. The limiting potentials UL of pure C3N, C2N, and g C3N4 are 0.96 V, 0.86 V, and 2.37 V, respectively, while these values are 0.63 V, 0.68 V, and 0.77 V with Cu or Pd modification. This work provides deep understanding of the catalytic properties of monolayer C1 xNx and guidance for synthesizing higher activity catalysts in the future.
author_names: Yuwen Cheng

Yan Song

Yumin Zhang
title: A systematic investigation of the catalytic performances of monolayer carbon nitride nanosheets C1 xNx.
venue: Physical chemistry chemical physics PCCP
year: 2020