Coherent electronic energy transfer and nonlinear polariton effects in anthracene-doped naphthalene crystals

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 1987

OSTI ID:5638127

Connolly, M A

The nature of electronic energy transfer in strain-free mounted anthracene-doped naphthalene single crystals at frequencies near that of the (0.0) a-exciton in naphthalene was probed using sensitized resonant two-photon fluorescence excitation (TPE) and second harmonic generation (SHG) spectroscopies. The naphthalene-to-anthracene TPE intensity ratios were found to be 1.2 and 1.6, for excitation of the zero-phonon transition at 1.6 K and 20 K, respectively. This result is consistent with coherent exciton-polariton electronic energy transfer at liquid helium temperatures, and incoherent transfer at high temperatures. Energy transfer for the pure and the anthracene-doped naphthalene systems under investigation was determined to be in the capture limited regime. The polariton trapping event is discussed in terms of scattering off a trap with subsequent trapping (i.e., capture) and scattering off a trap without subsequent trapping (i.e., trap scattering). Thermal broadening and temperature dependences of the TPE and SHG signal intensities for both naphthalene and anthracene are presented and are discussed in terms of the polariton fusion model. The experimental data do not agree with the theoretical predictions; this discrepancy is discussed in terms of the anomalous crystal habit (diamond plates) observed in the present investigation. The first report of a longitudinal exciton in a doped organic molecular system also is reported.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5638127
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
DOPED MATERIALS
ENERGY TRANSFER
NAPHTHALENE
ANTHRACENE
FLUORESCENCE SPECTROSCOPY
AROMATICS
CONDENSED AROMATICS
EMISSION SPECTROSCOPY
HYDROCARBONS
MATERIALS
ORGANIC COMPOUNDS
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties
360603 - Materials- Properties