Investigation of transport properties of perovskite single crystals by pulsed and DC bias transient current technique

Time-of-flight (ToF) transient current method is an important technique to study the transport characteristics of semiconductors. Here, both the direct current (DC) and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI$_{3}$ single crystal detector. Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement, the free hole mobility can be directly calculated to be about 22 cm$^{2}\cdot$V$^{-1}\cdot$s$^{-1}$, and the hole lifetime is around 6.5 μs-17.5 μs. Hence, the mobility-lifetime product can be derived to be $1.4\times 10^{-4}$ cm$^{2}\cdot$V$^{-1}$-$3.9\times 10^{-4}$ cm$^{2}\cdot$V$^{-1}$. The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias, which arises mainly from the inhomogeneous electric field distribution inside the perovskite. The positive space charge density can then be deduced to increase from 3.1$\times10^{10}$ cm$^{-3}$ to 6.89$\times 10^{10}$ cm$^{-3}$ in a bias range of 50 V-150 V. The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals, and is also helpful in obtaining a rough picture of the internal electric field distribution.     

GaN layers with different polarities prepared by radio frequency molecular beam epitaxy and characterized by Raman scattering

GaN layers with different polarities have been prepared by radio-frequency molecular beam epitaxy (RF-MBE) and characterized by Raman scattering. Polarity control are realized by controlling Al/N flux ratio during high temperature AlN buffer growth. The Raman results illustrate that the N-polarity GaN films have frequency shifts at $A_{1}$(LO) mode because of their high carrier density; the forbidden $A_{1}$(TO) mode occurs for mixed-polarity GaN films due to the destroyed translation symmetry by inversion domain boundaries (IDBS); Raman spectra for Ga-polarity GaN films show that they have neither frequency shifts mode nor forbidden mode. These results indicate that Ga-polarity GaN films have a better quality, and they are in good agreement with the results obtained from the room temperature Hall mobility. The best values of Ga-polarity GaN films are 1042 cm$^{2}$/Vs with a carrier density of 1.0$\times $10$^{17}$~cm$^{ - 3}$.     

Synthesis and characterization of Ca2Sn1-xCexO4 with blue luminescence originating from Ce^4＋ charge transfer transition

Ce^4＋-doped Ca2SnO4 with a one-dimensional structure, which emits bright blue light, is prepared by using a solid-state reaction method. The x-ray diffraction results show that the Ce^4＋ ions doped in Ca2SnO4 occupy the Sn^4＋ sites. The excitation and emission spectra of Ca2Sn1-xCexO4 appear to have broad bands with peaks at - 268nm and -442nm, respectively. A long excited-state lifetime （-83μs） for the emission from Ca2Sn1-xCexO4 suggests that the luminescence originates from a ligand-to-metal Ce^4＋ charge transfer （CT）. The luminescent properties of Ca2Snl_xCexO4 have been compared with those of Sr2CeO4, which is the only material reported so far to show Ce^4＋ CT luminescence. More interestingly, it is observed that the emission intensity of Ca2Sn1-xCexO4 with a small doping concentration （x - 0.03） is comparable to that of Sr2CeO4 in which the concentration of active centre is 100%.     

Spin polarization effect for molecule Ta2

Density functional theory （DFT） （B3p86） has been used to optimize the structure of the molecule Ta2. The result shows that the ground state of molecule Ta2 is a 7-multiple state and its electronic configuration is ^7∑u^＋, which shows the spin polarization effect for molecule Ta2 of transition metal elements for the first time. Meanwhile, spin pollution has not been found because the wavefunction of the ground state does not mix with those of higher states. So, the fact that the ground state of molecule Ta2 is a 7-multiple state indicates a spin polarization effect of molecule Ta2 of the transition metal elements, i.e. there exist 6 parallel spin electrons and the non-conjugated electrons are greatest in number. These electrons occupy different space orbitals so that the energy of molecule Ta2 is minimized. It can be concluded that the effect of parallel spin of the molecule Ta2 is larger than the effect of the conjugated molecule, which is obviously related to the effect of d-electron delocalization. In addition, the Murrell-Sorbie potential functions with parameters for the ground state ^7∑u^＋ and other states of the molecule Ta2 are derived. The dissociation energy De, equilibrium bond length Re and vibration frequency we for the ground state of molecule Ta2 are 4.5513eV, 0.2433nm and 173.06cm^-1, respectively. Its force constants f2, f3 and f4 are 1.5965×10^2aJ.nm^-2, -6.4722×10^3aJ·nm^-3 and 29.4851×10^4aJ·nm^-4, respectively. Other spectroscopic data we xe, Be and αe for the ground state of Ta2 are 0.2078cm^-1, 0.0315 cm^-1 and 0.7858×10^-4 cm^-1, respectively.     

Studies of K-shell x-ray energy shifts induced by MeV/u heavy ions

This paper reports that the K x-ray spectra of the thin target 47Ag, 48Cd, 49In and 50Sn were measured by an HPGe semi-conductor detector in collisions with 84.5 MeV 6C4+ ions. Our experiment revealed the Kα x-ray energy shifts were not obvious and the Kβ1 x-ray energy shifts were about 90～110 eV. The simple model of Burch et al has been previously used to calculate the K x-ray energy shifts due to an additional vacancy in 2p orbit. The present work extends the model of Burch to calculate the x-ray energy shifts of multiple ionized atoms induced by heavy ions with kinetic energy of MeV/u. In addition to our experimental results, many other experimental results are compared with the calculated values by using the model.     

Steady-state and transient electronic transport properties of β-(AlxGa1-x)2O3/Ga2O3 heterostructures: An ensemble Monte Carlo simulation

The steady-state and transient electron transport properties of $\beta $-(Al$_{x}$Ga$_{1-x}$)$_{2}$O$_{3}$/Ga$_{2}$O$_{3}$ heterostructures were investigated by Monte Carlo simulation with the classic three-valley model. In particular, the electronic band structures were acquired by first-principles calculations, which could provide precise parameters for calculating the transport properties of the two-dimensional electron gas (2DEG), and the quantization effect was considered in the $\varGamma $ valley with the five lowest subbands. Wave functions and energy eigenvalues were obtained by iteration of the Schrödinger-Poisson equations to calculate the 2DEG scattering rates with five main scattering mechanisms considered. The simulated low-field electron mobilities agree well with the experimental results, thus confirming the effectiveness of our models. The results show that the room temperature electron mobility of the $\beta $-(Al$_{0.188}$Ga$_{0.812}$)$_{2}$O$_{3}$/Ga$_{2}$O$_{3}$ heterostructure at 10 kV$ \cdot$cm$^{-1}$ is approximately 153.669 cm$^{2}\cdot$V$^{-1}\cdot$s$^{-1}$, and polar optical phonon scattering would have a significant impact on the mobility properties at this time. The region of negative differential mobility, overshoot of the transient electron velocity and negative diffusion coefficients are also observed when the electric field increases to the corresponding threshold value or even exceeds it. This work offers significant parameters for the $\beta$-(Al$_{x}$Ga$_{1-x}$)$_{2}$O$_{3}$/Ga$_{2}$O$_{3}$ heterostructure that may benefit the design of high-performance $\beta$-(Al$_{x}$Ga$_{1-x}$)$_{2}$O$_{3}$/Ga$_{2}$O$_{3}$ heterostructure-based devices.     

Judd-Oflet analysis of spectrum and laser performance of Ho：YAP crystal end-pumped by 1.91μm Tm：YLF laser

The Ho:YAP crystal is grown by the Czochralski technique.The room temperature polarized absorption spectra of Ho:YAP crystal was measured on a c cut sample with 1 at% holmium.According to the obtained Judd-Ofelt intensity parameters Ω2 = 1.42 × 10-20 cm2,Ω4 = 2.92 × 10-20 cm2,and Ω6 = 1.71 × 10-20 cm2,this paper calculated the fluorescence lifetime to be 6 ms for 5I7 →5 I8 transition,and the integrated emission cross section to be 2.24×10-18 cm2.It investigates the room temperature Ho:YAP laser end pumped by a 1.91 μm Tm:YLF laser.The maximum output power was 4.1 W when the incident 1.91 μm pump power was 14.4 W.The slope efficiency is 40.8%,corresponding to an optical to optical conversion efficiency of 28.4%.The Ho:YAP output wavelength was centred at 2118 nm with full width at half maximum of about 0.8 nm.     

Spin polarization effect for Os2 molecule

Density functional Theory （DFT） （B3p86） of Gaussian03 has been used to optimize the structure of Os2 molecule. The result shows that the ground state for Os2 molecule is 9-multiple state and its electronic configuration is ^9∑^＋g, which shows spin polarization effect of Os2 molecule of transition metal elements for the first time. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions with higher energy states. So, the fact that the ground state for Os2 molecule is a 9-multiple state is indicative of spin polarization effect of Os2 molecule of transition metal elements. That is, there exist 8 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of Os2 molecule is minimized. It can be concluded that the effect of parallel spin of Os2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state ^9∑^＋g and other states of Os2 molecule are derived. Dissociation energy De for the ground state of Os2 molecule is 3.3971eV, equilibrium bond length Re is 0.2403nm, vibration frequency ωe is 235.32cm^-1. Its force constants f2, f3, and f4 are 3.1032×10^2aJ·nm^-2, -14.3425×10^3aJ·nm^-3 and 50.5792×10^4aJ·nm^-4 respectively. The other spectroscopic data for the ground state of Os2 molecule ωexe, Be and ae are 0.4277cm^- 1, 0.0307cm^- 1 and 0.6491 × 10^-4cm^-1 respectively.     

Judd--Ofelt analysis of spectra and experimental evaluation of laser performance of Tm3+ doped Lu2SiO5 crystal

This paper reports that the Tm^3＋：Lu2SiO5 （Tm：LSO） crystal is grown by Czochralski technique. The roomtemperature absorption spectra of Tm：LSO crystal are measured on a b-cut sample with 4 at.% thulium. According to the obtained Judd-Ofelt intensity parameters Ω2=9.3155×10^-20 cm^2, Ω4=8.4103×10^-20 cm^2, Ω6=1.5908×10^-20 cm^2, the fluorescence lifetime is calculated to be 2.03 ms for ^3F4 → ^3H6 transition, and the integrated emission cross section is 5.81×10^-18 cm^2. Room-temperature laser action near 2μm under diode pumping is experimentally evaluated in Tm：LSO. An optical-optical conversion efficiency of 9.1% and a slope efficiency of 16.2% are obtained with continuouswave maximum output power of 0.67 W. The emission wavelengths of Tm：LSO laser are centred around 2.06μm with spectral bandwidth of -13.6 nm.     

Enhanced interface properties of diamond MOSFETs with Al_2O_3 gate dielectric deposited via ALD at a high temperature

The interface state of hydrogen-terminated(C–H) diamond metal–oxide–semiconductor field-effect transistor(MOSFET) is critical for device performance. In this paper, we investigate the fixed charges and interface trap states in C–H diamond MOSFETs by using different gate dielectric processes. The devices use Al_2O_3 as gate dielectrics that are deposited via atomic layer deposition(ALD) at 80℃ and 300℃, respectively, and their C–V and I–V characteristics are comparatively investigated. Mott–Schottky plots(1/C~2–VG) suggest that positive and negative fixed charges with low density of about 1011 cm~(-2) are located in the 80-℃-and 300-℃ deposition Al_2O_3 films, respectively. The analyses of direct current(DC)/pulsed I–V and frequency-dependent conductance show that the shallow interface traps(0.46 e V–0.52 e V and0.53 e V–0.56 e V above the valence band of diamond for the 80-℃ and 300-℃ deposition conditions, respectively) with distinct density(7.8 × 10~(13) e V~(-1)·cm~(-2)–8.5 × 10~(13) e V-1·cm~(-2) and 2.2 × 1013 e V~(-1)·cm~(-2)–5.1 × 10~(13) e V~(-1)·cm~(-2) for the80-℃-and 300-℃-deposition conditions, respectively) are present at the Al_2O_3/C–H diamond interface. Dynamic pulsed I–V and capacitance dispersion results indicate that the ALD Al_2O_3 technique with 300-℃ deposition temperature has higher stability for C–H diamond MOSFETs.     

The splitting of low-lying states for hydroxyl molecule under spin--orbit coupling

The splitting of potential energy curves for the states $X^{2}\Pi _{3/2}$, $^{2}\Pi _{1/2}$ and $A^{2}\Sigma ^{ +}$ of hydroxyl OH under spin--orbit coupling (SOC) has been calculated by using the SO multi-configuration quasi-degenerate perturbation theory (SO-MCQDPT). Their Murrell--Sorbie (M--S) potential functions have been derived, then, the spectroscopic constants for $X^{2}\Pi _{3/2}$,$^{ 2}\Pi _{1/2}$ and $A^{2}\Sigma ^{ + }$ have been derived from the M--S function. The calculated dissociation energies for the three states are $D_{0}$[OH($X^{2}\Pi _{3/2})$]=34966.632cm$^{-1}$, $D_{0}$[OH($^{2}\Pi _{1/2})$]=34922.802cm$^{-1}$, and $D_{0}$[OH($A^{2}\Sigma ^{ + })$]=17469.794cm$^{-1}$, respectively. The vertical excitation energy $\nu [ {{ }^2\Pi _{1/2} ( {\nu = 0} ) \to {X}{ }^2\Pi _{3/2} ( {\nu = 0} )} ] = 139.6{\rm cm}^{-{\rm 1}}$. All the spectroscopic data for the $X^{2}\Pi _{3/2}$ and $^{2}\Pi _{1/2 }$ are given for the first time except the dissociation energy of $X^{2}\Pi _{3/2}$.     

High energy electron radiation effect on Ni/4H-SiC SBD and Ohmic contact

The Ni/4H-SiC Schottky barrier diodes (SBDs) and transfer length method (TLM) test patterns of Ni/4H-SiC Ohmic contacts were fabricated, and irradiated with 1~MeV electrons up to a dose of 3.43× 10¹⁴~e/cm^-2. After radiation, the forward currents of the SBDs at 2~V decreased by about 50%, and the reverse currents at -200~V increased by less than 30%. Schottky barrier height (φ _B ) of the Ni/4H-SiC SBD increased from 1.20~eV to 1.21~eV under 0~V irradiation bias, and decreased from 1.25~eV to 1.19~eV under -30~V irradiation bias. The degradation of φ _B could be explained by the variation of interface states of Schottky contacts. The on-state resistance (R_s) and the reverse current increased with the dose, which can be ascribed to the radiation defects in bulk material. The specific contact resistance (\rho_c) of the Ni/SiC Ohmic contact increased from 5.11× 10⁵~Ωega.cm² to 2.97× 10^-4~Ωega.cm².     

The research on suspended ZnO nanowire field-effect transistor

This paper reports that a novel type of suspended ZnO nanowire field-effect transistors (FETs) were successfully fabricated using a photolithography process, and their electrical properties were characterized by I--V measurements. Single-crystalline ZnO nanowires were synthesized by a hydrothermal method, they were used as a suspended ZnO nanowire channel of back-gate field-effect transistors (FET). The fabricated suspended nanowire FETs showed a p-channel depletion mode, exhibited high on--off current ratio of ～10⁵. When V_DS=2.5 V, the peak transconductances of the suspended FETs were 0.396 μS, the oxide capacitance was found to be 1.547 fF, the pinch-off voltage V_TH was about 0.6 V, the electron mobility was on average 50.17 cm²/Vs. The resistivity of the ZnO nanowire channel was estimated to be 0.96× 10²Ω cm at V_GS = 0 V. These characteristics revealed that the suspended nanowire FET fabricated by the photolithography process had excellent performance. Better contacts between the ZnO nanowire and metal electrodes could be improved through annealing and metal deposition using a focused ion beam.     

Ab initio calculations on the α^3∑u^＋ state properties of dimer ^7Li2

The comparison between single-point energy scanning （SPES） and geometry optimization （OPT） in determining the equilibrium geometry of the α^3∑u^＋ state for ^7Li2 is made at numerous basis sets such as 6-311＋＋G（2df）, cc-PVTZ, 6-311＋＋G（2df, p）, 6-311G（3df,3pd）, 6-311＋＋G（2df,2pd）, D95（3df,3pd）, 6-311＋＋G, DGDZVP, 6-311＋＋G（3df,2pd）, 6-311G（2df,2pd）, D95V＋＋, CEP-121G, 6-311＋＋G（d,p）, 6-311＋＋G（2df, pd） and 6-311＋＋G（3df,3pd） in full active space using a symmetry-adapted-cluster/ symmetry-adapted-cluster configuration-interaction （SAC/SAC=CI） method presented in Gaussian03 program package. The difference of the equilibrium geometries obtained by SPES and by OPT is reported. Analyses show that the results obtained by SPES are more reasonable than those obtained by OPT. We have calculated the complete potential energy curves at those sets over a wide internuclear distance range from about 3.0α0 to 37.0α0, and the conclusion is that the basis set cc-PVTZ is the most suitable one. With the potential obtained at ccopVTZ, the spectroscopic data （Te, De, D0, ωe,ωeХe, αe and Be） are computed and they are 1.006 eV, 338.71 cm^-1, 307.12 cm^-1, 64.88 cm^-1, 3.41 cm^-1, 0.0187 cm^-1 and 0.279 cm^-1, respectively, which are in good agreement with recent measurements. The total 11 vibrational states are found at J=0. Their corresponding vibrational levels and classical turning points are computed and compared with available RKR data, and good agreement is found. One inertial rotation constant （By） and six centrifugal distortion constants （Dr Hv, Lv, My, Nv, and Ov） are calculated. The scattering length is calculated to be -27.138α0, which is in good accord with the experimental data.     

A new analysis of the ν2 fundamental band of H2O^＋＊

This paper reports that the absorption spectra of H2O^＋ have been measured by tunable mid-infrared diode laser spectroscopy in the spectral range of 1100-1380 cm^-1. The H2O＋ ions are generated in an AC glow discharge of the gaseous mixtures of H2O/He and detected with the velocity modulation technique. Forty new lines are assigned to the ν2 fundamental band of H2O^＋ （X^2B1）. The observed lines together with other data published previously are fitted to the standard effective Hamiltonian of an asymmetric top, yielding a set of improved rotational constants, spin-rotation constants and their quartic and sextic centrifugal distortion constants for the ν2=1 vibrational state of H2O＋.     

Spin polarization effect for Cr2 molecule

Density functional theory （DFT） （B3P86） of Gaussian 03 has been used to optimize the structure of the Cr2 molecule, a transition metal element molecule. The result shows that the ground state for the Cr2 molecule is a 13- multiple state, indicating that there exists a spin polarization effect in the Cr2 molecule. Meanwhile, we have not found any spin pollution because the wave function of the ground state does not mingle with wave functions of higher-energy states. So the ground state for Cr2 molecule being a 13-multiple state is indicative of spin polarization effect of the Cr2 molecule among transition metal elements, that is, there are 12 parallel spin electrons in the Cr2 molecule. The number of non-conjugated electrons is greatest. These electrons occupy different spatial orbitals so that the energy of the Cr2 molecule is minimized. It can be concluded that the effect of parallel spin in the Cr2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell Sorbie potential functions with the parameters for the ground state and other states of the Cr2 molecule are derived. The dissociation energy De for the ground state of the Cr2 molecule is 0.1034eV, equilibrium bond length Re is 0.3396 nm, and vibration frequency we is 73.81cm^-1. Its force constants f2, f3 and f4 are 0.0835, -0.2831 and 0.3535 aJ. nm^-4 respectively. The other spectroscopic data for the ground state of the Cr2 molecule ωeχe, Be and αe are 1.2105, 0.0562 and 7.2938 x 10^-4cm^-1 respectively.     

Physical analysis of normally-off ALD Al2O3/GaN MOSFET with different substrates using self-terminating thermal oxidation-assisted wet etching technique

Based on the self-terminating thermal oxidation-assisted wet etching technique, two kinds of enhancement mode Al$_{2}$O$_{3}$/GaN MOSFETs (metal-oxide-semiconductor field-effect transistors) separately with sapphire substrate and Si substrate are prepared. It is found that the performance of sapphire substrate device is better than that of silicon substrate. Comparing these two devices, the maximum drain current of sapphire substrate device (401 mA/mm) is 1.76 times that of silicon substrate device (228 mA/mm), and the field-effect mobility ($\mu_{\rm FEmax}$) of sapphire substrate device (176 cm$^{2}$/V$\cdot$s) is 1.83 times that of silicon substrate device (96 cm$^{2}$/V$\cdot$s). The conductive resistance of silicon substrate device is 21.2 $\Omega {\cdot }$mm, while that of sapphire substrate device is only 15.2 $\Omega {\cdot }$mm, which is 61% that of silicon substrate device. The significant difference in performance between sapphire substrate and Si substrate is related to the differences in interface and border trap near Al$_{2}$O$_{3}$/GaN interface. Experimental studies show that (i) interface/border trap density in the sapphire substrate device is one order of magnitude lower than in the Si substrate device, (ii) Both the border traps in Al$_{2}$O$_{3}$ dielectric near Al$_{2}$O$_{3}$/GaN and the interface traps in Al$_{2}$O$_{3}$/GaN interface have a significantly effect on device channel mobility, and (iii) the properties of gallium nitride materials on different substrates are different due to wet etching. The research results in this work provide a reference for further optimizing the performances of silicon substrate devices.     

Enhancement of spin-orbit torque efficiency by tailoring interfacial spin-orbit coupling in Pt-based magnetic multilayers

We study inserting Co layer thickness-dependent spin transport and spin-orbit torques (SOTs) in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance. The interfacial perpendicular magnetic anisotropy (IPMA) energy density ($K_{\rm s}= 2.7 $ erg/cm$^{2}$, 1 erg = 10$^{-7}$ J), which is dominated by interfacial spin-orbit coupling (ISOC) in the Pt/Co interface, total effective spin-mixing conductance $(G_{\mathrm{eff,tot}}^{\mathrm{\uparrow \downarrow }}=\mathrm{0.42\times }{10}^{15} \mathrm{\Omega }^{-1}\cdot\mathrm{m}^{-2}$) and two-magnon scattering ($\beta_{\mathrm{TMS}}= 0.46 {\mathrm{nm}}^{2}$) are first characterized, and the damping-like torque ($\xi_{\mathrm{DL}}= 0.103$) and field-like torque ($\xi _{\mathrm{FL}}=-0.017$) efficiencies are also calculated quantitatively by varying the thickness of the inserting Co layer. The significant enhancement of $\xi_{\mathrm{DL}}$ and $\xi_{\mathrm{FL}}$ in Pt/Co/Py than Pt/Py bilayer system originates from the interfacial Rashba-Edelstein effect due to the strong ISOC between Co-3d and Pt-5d orbitals at the Pt/Co interface. Additionally, we find a considerable out-of-plane spin polarization SOT, which is ascribed to the spin anomalous Hall effect and possible spin precession effect due to IPMA-induced perpendicular magnetization at the Pt/Co interface. Our results demonstrate that the ISOC of the Pt/Co interface plays a vital role in spin transport and SOTs-generation. Our finds offer an alternative approach to improve the conventional SOTs efficiencies and generate unconventional SOTs with out-of-plane spin polarization to develop low power Pt-based spintronic via tailoring the Pt/FM interface.     

Cathodic shift of onset potential on TiO2 nanorod arrays with significantly enhanced visible light photoactivity via nitrogen/cobalt co-implantation

Despite anionic doping has been widely implemented to increase the visible light activity of TiO$_{2}$, it often gives rise to a dramatical anodic shift in current onset potential. Herein, we show an effective method to achieve the huge cathodic shift of TiO$_{2}$ photoanode with significantly enhanced visible light photo-electrochemical activity by nitrogen/cobalt co-implantation. The nitrogen/cobalt co-doped TiO$_{2}$ nanorod arrays (N/Co-TiO$_{2}$) exhibit a cathodic shift of 350 mV in onset potential relative to only nitrogen-doped TiO$_{2}$ (N-TiO$_{2}$). Moreover, the visible-light ($\lambda >420 $ nm) photocurrent density of N/Co-TiO$_{2}$ reaches 0.46 mA/cm$^{2}$, far exceeding 0.07 mA/cm$^{2}$ in N-TiO$_{2}$ at 1.23 V $versus$ reversible hydrogen electrode (RHE). Systematic characterization studies demonstrate that the enhanced photo-electrochemical performance can be attributed to the surface synergic sputtering of high-energy nitrogen/cobalt ions.     

Elastic collisions of sulfur and hydrogen in their ground states at low temperatures and spectroscopic parameters of SH（X^2∏） radical

This paper constructs the interaction potential of the SH（X^2∏） radical by using the coupled-cluster singlesdoubles-approximate-triples theory combining the correlation-consistent quintuple basis set augmented with the diffuse functions, aug-cc-pV5Z, in the valence range. Employing the potential, it accurately determines the spectroscopic parameters. The present De, Re, ωe, ωeχe, ae and Be values are of 3.7767eV, 0.13424nm, 2699.846 cm^-1, 47.7055 cm^-1, 0.2639cm^-1 and 9.4414 cm^-1, respectively, which are in excellent agreement with those obtained from the measure- ments. A total of 19 vibrational states has been found when J = 0 by solving the radial SchrSdinger equation of nuclear motion. The complete vibrational levels, classical turning points, initial rotation and centrifugal distortion constants when J = 0 are reported for the first time, which are in good accord with the experimental results. The total and various partial-wave cross sections are computed for the elastic collisions of sulfur and hydrogen in their ground states at low temperatures when two atoms approach each other along the SH（X^2∏） potential energy curve. Over the impact energy range from 1.0×10^-11 to 1.0×10^-4 a.u., eight shape resonances have been found in the total elastic cross sections. For each shape resonance, the resonant energy is accurately calculated. Careful investigations have pointed out that these resonances result from the 1 = 0, 1, 2, 3, 4, 6, 7, 8 partial-wave contributions.