Radiative decay of polaron-excitons in poly(phenylene vinylene)

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.13162· OSTI ID:5967068

Bronold, F X; Saxena, A; Bishop, A R ^[1]

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1. Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Starting from a nondegenerate-ground-state Su-Schrieffer-Heeger-like model Hamiltonian for poly(phenylene vinylene) we study the effect of electron-lattice coupling on the radiative recombination of polaron-excitons, using a lattice relaxation theory which explicitly takes into account multimode effects. We provide a detailed microscopic description of the decay process with emphasis on the fact that the phonon modes of the excited state---the polaron-exciton---are different from the ground-state phonon modes. We find that at zero temperature all accepting modes are within an almost dispersionless ground-state phonon branch. Therefore, as long as the polaron-exciton is in its vibrational ground state a simple, empirical, single-mode description of the recombination (photoluminescence) is feasible. However, the complicated phonon structure of the polaron-exciton---including localized as well as extended modes---renders an Einstein desciption of promoting modes meaningless. We thus expect that in processes where promoting modes are involved a single-mode model breaks down.

• OSTI ID: 5967068
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:17; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

665430* -- Other Topics in Quantum Fluids & Solids-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARYL RADICALS
DECAY
EXCITONS
OSCILLATION MODES
PARTICLE DECAY
PHENYL RADICALS
PHONONS
POLARONS
POLYMERS
QUASI PARTICLES
RADIATIVE DECAY
RADICALS
RECOMBINATION
SINGLE-PARTICLE MODES