Energy localization in substitutionally disordered solids. II. Studies by optical and optically detected magnetic resonance spectroscopy
In continuation of previous work, we present experimental measurements on the localization of triplet Frenkel excitons in isotopically doped phenazine and 1,4-dibromonaphthalene (2-D and 1-D effective excitation transfer topology, respectively). Dependence of steady state impurity aggregate (monomer, dimers, etc.) emission intensities on temperature, concentration of dopant, and the dimensionality is experimentally measured and theoretically modeled. Effects of phonons and excited state lifetimes are explicitly included in a numerical simulation of the data by average-lattice rate equations. The rate equations explain the major features of the experimental data quite well. For use in the rate equations, we have performed Monte Carlo experiments to determine cluster probabilities on 1-D and anisotropic 2-D lattices. Finally, the relevance of these findings to Anderson localization and percolation theory is discussed.
Additional Information© 1980 American Institute of Physics. Received 12 December 1978; accepted 25 September 1979. We wish to thank the National Science Foundation (Grant No. DMR77-19578) for the partial support of this work. Acknowledgment is also made to the donors of the Petroleum Research Fund, administered by ACS, and to DOE and Research Corp. for partial support of this work. We have benefitted from discussions with several people: Darryl Smith, J. Lemaistre and Ray Orbach. We wish to thank A. Nichols for the help with the 1-D cluster statistics and computer work. Thanks also go to R. Kopelman and J. Jortner and J. Klafter for providing us with preprints of their work. This work was done in partial fulfillment of the Ph.D. requirement of D.D. Smith at the California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-04072008-141328 [D.P.M. was a] Fulbright-Hays Graduate Student. [A.H.Z. was an] Alfred P. Sloan Fellow, and Camille and Henry Dreyfus Teacher-Scholar. Arthur Amos Noyes Laboratory of Chemical Physics, Contribution No. 5931.
Published - SMIjcp80.pdf