Calculation of photon angular distribution and polarization for radiative recombination for highly charged helium-like ions

A systematic study is carried out on the angular distribution and polarization of photons emitted following radiative recombination of He-like ions by a non-relativistic dipole approximation. In order to incorporate the screening effect due to inner-shell electrons, a distorted wave approach is used. The dependence of the calculated angular distribution and polarization on the reduced-energy and nuclear charge are fitted by the corresponding empirical formulas, respectively.     

Electron-Vibrational Structure in the 2.8–3.6 eV Range of the Photoluminescence Spectrum of Borozon

The electron-vibrational structure in the 2.8–3.6 eV range of the photoluminescence spectrum of borozon polycrystals and single crystals has been investigated. The existence of the structure of the leading PF-1 line, its change depending on the measurement temperature and the quality of the sample and after irradiation at low temperature and annealing, and the electron-phonon interaction on the PF center with the participation of longitudinal optical phonons made it possible to develop a model of donor-acceptor recombination for interpreting the nature of the PF center.     

表面复合速度和结深对硅扩散n十-p 结太阳电池性能的影响

假设扩散区的杂质分布为高斯分布,本文给出了扩散n~+-P结太阳电池扩散n~+区少子连续性方程一个形式简单的解。在此基础上对若干实例进行了计算和分析,以研究表面复合速度和结深对太阳电池性能的影响。 本文指出,为使太阳电池有高的收集效率,必须把表面复合速度控制在10~4cm/s以下。除了表面复合速度以外,也研究了杂质分布引起的内建漂移场对光生少子在表面复合的影响。内建漂移场与结深有关。本文指出,与较高的漂移场相应的浅结更有利于削弱光生少子在表面的复合。     

Long‐lived species generated via irradiation of poly(methyl methacrylate) containing pyrene

The fate of long‐lived species [pyrene (Py) radical cations and Py–cyclohexadienyl‐type radicals] generated by electron‐beam irradiation at room temperature in poly(methyl methacrylate) (PMMA) doped with Py is described. The separation of reacting solute intermediates and the relaxation phenomena seem to be the main factors limiting the reactivity of long‐lived Py species in the PMMA matrix. The temperature‐stimulated recombination of ionic species in PMMA doped with Py results in Py excited‐state formation. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4110–4118, 2001     

Recombination of U 92 + ions with electrons

Recombination of fully stripped U⁹²⁺ ions with electrons has been investigated at the Experimental Storage Ring (ESR) in Darmstadt. Absolute recombination rate coefficients have been measured for relative energies from 0 to 33 eV. For energies greater than 20 meV the experimental result is well described by the theory for radiative recombination (RR). Below 20 meV the experimental rate increasingly exceeds the RR calculation as observed previously in the recombination of light bare ions as well as of Bi⁸³⁺. This low-energy rate enhancement is shown to scale as Z^2.6 for bare ions, where Z is the atomic number of the ion. The U⁹²⁺ recombination rate enhancement is insensitive to changes of the electron density. Variation of the magnetic guiding field strength from 80 mT to 120 mT resulted in oscillations of the recombination rate at 0 eV. The oscillations are partly attributed to changes of the transverse electron temperature accompanying the change of the magnetic guiding field strength; partly they may be caused by uncompensated small changes of the interaction angle between the two beams. Received 1st March 2001 and Received in final form 20 April 2001     

Calculation of photon angular distribution and polarization for radiative recombination for high-charged hydrogen-like ions

In this paper a systematic study is carried out on the angular distribution and polarization of photons emitted following radiative recombination of H-like ions by a non-relativistic dipole approximation. In order to incorporate the screening effect due to inner-shell electrons, a distorted wave approach is used. The dependences of the calculated angular distribution and polarization on the reduced energy and nuclear charge are fitted by the corresponding empirical formulas respectively.     

单泡声致发光过程的等离子体描述

对单泡声致发光过程采用等离子体描述,考虑了各种等离子体输运过程,假设了声致发光的轫致辐射机制,数值模拟的结果与实验很好地吻合,有力地支持了声致发光的热转向的解释,预言了声致发光中可能出现的极端电现象,对各物理量时空剖面的分析表明,强电场的出现中能产生的Ｒａｙｌｅｉｇｈ－Ｔａｙｌｏｒ不稳定性有制约作用,这可能是声致发光约１０＾１２能量汇集的原因之一。     

Sano-Tachiya-Noolandi-Hong versus Onsager modelling of charge photogeneration in organic solids

We have studied the electric field dependence of charge photogeneration efficiency in organic solids for various radial distribution functions (Dirac delta, Gaussian, exponential) of initial e-h pairs in the framework of Sano-Tachiya-Noolandi-Hong (STNH) theory assuming that the final recombination (capture reaction) proceeds on a sphere of finite radius (a) with a finite velocity (κ). We compare the STNH results with the conventional Onsager theory assuming a = 0. We show that charge photogeneration is more enhanced, especially in low-electric field range, for broader initial pair distributions and for smaller final recombination velocities. We compare theoretical results with experimental data taken from electromodulation of photoluminescence (EML) for two archetypical organic photoconductors, Alq₃ and Ir(ppy)₃, commonly used as emitters in organic LEDs. From analysis of our results we infer the lower limit of final recombination velocity, κ = 0.2-2 cm/s, in vacuum evaporated films of Alq₃ and Ir(ppy)₃ which compares favorably with an evaluation of this quantity in amorphous solids.     

Vibrational temperature of the adlayer in the ‘hot-atom’ reaction mechanism

The hot-atom reaction mechanism brings about reaction rates several orders of magnitude higher than those expected in the case of adatoms which have thermalized with the surface. This paper addresses the issue of a possible thermodynamic characterization of the adlayer under reactive conditions and at the steady state. In turn, this implies having to determine the temperature of the adatoms. This is done by means of a nonequilibrium statistical thermodynamic approach, by exploiting a suitable definition of the entropy. The interplay between reaction rate, vibrational temperature of the adatoms and adsorbed quantities is highlighted. This paper shows that the vibrational temperature depends on reaction rate, logarithmically and exhibits a non-linear scaling on physical quantities linked to the energetics of the reaction, namely the adsorption energy and the binding energy of the molecule. The present modeling is also discussed in connection with response equations of nonequilibrium thermodynamics.     

Optical mixing in InSb

Abstract

In this paper, the authors have derived the expression for the combination frequency components ω₃ = 2ω₁-ω₂ in the current density by solving the appropriate Boltzmann transfer equation for electrons, when two laser beams of frequencies of ω₁ and ω₂ are incident on a degenerate nonparabolic semiconductor viz. InSb; the nonlinearity due to collision mechanism as well as the nonparabolicity of conduction band has been taken into account. The ionized impurity scattering has been considered to be the sole mechanism of electron scattering. The expression for the current density is further substituted in the wave equation to obtain the expression for the amplitude of combination frequency wave in the transmitted component. The calculated value of output power of frequency ω₂ is found to be 1/10th of the experimental value (Patel, Slusher and Fleury, 1966), ⁽⁷⁾ and thus is in better agreement as compared to earlier investigators (Wolff and Pearson, 1966; Kaw, 1968). ^{(5, 10)}