Picosecond excitation transport in disordered systems

Technical Report · Sun Nov 01 04:00:00 EST 1987

OSTI ID:5259131

Hart, D E

Time-resolved fluorescence decay profiles are used to study excitation transport in 2- and 3-dimensional disordered systems. Time-correlated single photon counting detection is used to collect the fluorescence depolarization data. The high signal-to-noise ratios afforded by this technique makes it possible to critically examine current theories of excitation transport. Care has been taken to eliminate or account for the experimental artifacts common to this type of study. Solutions of 3,3'-diethyloxadicarbocyanine iodide (DODCI) in glycerol serve as a radomly distributed array of energy donors in 3-dimensions. A very thin sample cell ()approximately/ 2 ..mu..m) is used to minimize the effects of fluorescence self-absorption on the decay kinetics. Evidence of a dynamic shift of the fluorescence spectrum of DODCI in glycerol due to solvent reorganization is presented. The effects of excitation trapping on the decay profiles is minimized in the data analysis procedure. The 3-body theory of Gochanour, Andersen, and Fayer (GAF) and the far less complex 2-particle analytic theory of Huber, Hamilton, and Barnett yield indistinguishable fits to the data over the wide dynamic range of concentrations and decay times studied.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5259131
• Report Number(s): IS-T-1290; ON: DE88007615
• Country of Publication: United States
• Language: English

Related Subjects

656002* -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALCOHOLS
AMINES
COMPUTER CODES
CORRELATIONS
DATA ANALYSIS
DEPOLARIZATION
DETECTION
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUORESCENCE
FUNCTIONS
GLYCEROL
GREEN FUNCTION
HYDROXY COMPOUNDS
LEAST SQUARE FIT
LIPIDS
LUMINESCENCE
MAXIMUM-LIKELIHOOD FIT
MEASURING METHODS
N CODES
NEUTRAL-PARTICLE TRANSPORT
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
PHOTODIODES
PHOTON TRANSPORT
RADIATION TRANSPORT
RADIATIVE DECAY
RESOLUTION
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SIGNAL-TO-NOISE RATIO
TIME RESOLUTION
TIMING PROPERTIES
TRANSPORT THEORY