9 research outputs found
Peculiarities of Electron-Phonon Interaction in Centers of Single Crystals
The luminescence excitation and emission spectra of SrCl₂:Pr single crystals containing 0.2 mol. % Pr were investigated at T=10 K using vacuum ultraviolet synchrotron radiation. From analysis of the fine structure of the low-energy excitation band of an activator, the following main frequencies associated with the local structure of the activator centers were found in the phonon spectrum of SrCl₂:Pr crystal: 194; 210; 266 and 298 cm⁻¹
Modeling of X-ray excited luminescence intensity dependence on the nanoparticle size
The thermalization length distribution of electrons over their kinetic energy in a conduction band is calculated on the basis of the data on the electron effective mass, density of states in conduction band, dielectric permittivity and energy of longitudinal optical phonons. The method of modeling of a recombinational luminescence intensity dependence on the nanoparticle size is proposed on the basis of the assumption that the contribution to a recombinational luminescence gives only those charge carriers which in the result of thermalization did not reach a near-surface layer of nanoparticles. Using such the approach the theoretical dependence of recombinational luminescence intensity on the nanoparticle size for LaPO and LuPO are calculated. The revealed correlation of experimental and theoretical dependences confirms that the commensurability of electron thermalization length with nanoparticle size is the main reason of the sharp decrease of X-ray excited luminescence intensity when the nanoparticle size decreases
Modeling of X-ray excited luminescence intensity dependence on the nanoparticle size
The thermalization length distribution of electrons over their kinetic energy in a conduction band is calculated on the basis of the data on the electron effective mass, density of states in conduction band, dielectric permittivity and energy of longitudinal optical phonons. The method of modeling of a recombinational luminescence intensity dependence on the nanoparticle size is proposed on the basis of the assumption that the contribution to a recombinational luminescence gives only those charge carriers which in the result of thermalization did not reach a near-surface layer of nanoparticles. Using such the approach the theoretical dependence of recombinational luminescence intensity on the nanoparticle size for LaPO and LuPO are calculated. The revealed correlation of experimental and theoretical dependences confirms that the commensurability of electron thermalization length with nanoparticle size is the main reason of the sharp decrease of X-ray excited luminescence intensity when the nanoparticle size decreases