Exciton-exciton interactions in CdWO4 irradiated by intense femtosecond vacuum ultraviolet pulses

M. Kirm (1) , V. Nagirnyi (1) , E. Feldbach (1) , M. de Grazia (2) , Bertrand Carre (2) , Hamed Merdji (2) , Stéphane Guizard (3) , G. Geoffroy (3) , Jerome Gaudin (4) , N. Fedorov (5) , P. Martin (5) , A. N. Vasil'Ev (6) , A.N. Belsky (7)

1 Institute of Physics [Tartu]
2 SPAM - Service des Photons, Atomes et Molécules
3 LSI - Laboratoire des Solides Irradiés
4 European XFEL
5 CELIA - Centre d'Etudes Lasers Intenses et Applications
6 Physics Faculty - Moscow State University
7 LPCML - Laboratoire de Physico-Chimie des Matériaux Luminescents

Exciton-exciton interaction is experimentally revealed and quantitatively analyzed in a wide band-gap scintillator material CdWO4. Under high-intensity femtosecond vacuum ultraviolet excitation, the CdWO4 luminescence is quenched, while its decay becomes essentially nonexponential. We propose an analytical model, which successfully reproduces the decay kinetics recorded in a wide range of excitation densities. The dipole-dipole interaction between excitons leading to their nonradiative decay is shown to be the main cause of a nonproportional response common for many scintillators.

Keywords: CADMIUM TUNGSTATE SCINTILLATORS; NON-PROPORTIONALITY; LUMINESCENCE; EXCITATION; CRYSTALS; DECAY; RELAXATION; ABSORPTION; STATE

Domains: Engineering Sciences [physics]; Mechanics [physics.med-ph]

M. Kirm, V. Nagirnyi, E. Feldbach, M. de Grazia, Bertrand Carre, et al.. Exciton-exciton interactions in CdWO4 irradiated by intense femtosecond vacuum ultraviolet pulses. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 79, pp.233103. ⟨10.1103/PhysRevB.79.233103⟩. ⟨hal-01068414⟩