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Title: Dye-capped semiconductor nanoclusters. Excited state and photosensitization aspects of rhodamine 6G H-aggregates bound to SiO{sub 2} and SnO{sub 2} colloids

Abstract

SiO{sub 2} and SnO{sub 2} colloids are capped with a cationic dye, rhodamine 6G, by electrostatic interaction. The close packing of these dye molecules on the negatively charged SiO{sub 2} and SnO{sub 2} colloid results in the formation of H-aggregates. These aggregates are nonfluorescent but can inject electrons from the excited state into SnO{sub 2} colloids. The photophysical and photochemical properties of rhodamine-6G-aggregate on SiO{sub 2} and SnO{sub 2} colloids have been investigated using picosecond laser flash photolysis. Charge injection from the excited dye aggregate into SnO{sub 2} nanocrystallites occurs with a rate constant of 5.5 x 10{sup 9} s{sup -1}. The application of these dye aggregates in extending the photoresponse of nanocrystalline SnO{sup 2} film has been demonstrated by constructing a photoelectrochemical cell. A maximum incident photon-to-photocurrent efficiency of nearly 1% was observed for the photosensitized current generation. Fast reverse electron transfer between the injected electron and the cation radical of the dye aggregate is a limiting factor in maximizing the incident photon-to-photocurrent efficiency (IPCE). 65 refs., 11 figs.

Authors:
 [1]; ;  [1];  [2]
  1. Univ. of Notre Dame, IN (United States)
  2. Universite du Quebec a Trois Rivieres (Canada)
Publication Date:
OSTI Identifier:
282994
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry
Additional Journal Information:
Journal Volume: 100; Journal Issue: 26; Other Information: PBD: 27 Jun 1996
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 40 CHEMISTRY; RHODAMINES; PHOTOCHEMICAL REACTIONS; PHOTOSENSITIVITY; SEMICONDUCTOR MATERIALS; DYES; EXCITED STATES; SILICA; TIN OXIDES; COLLOIDS; ELECTRON TRANSFER

Citation Formats

Nasr, C, Universite du Quebec a Trois Rivieres, Liu, D, Kamat, P V, and Hotchandani, S. Dye-capped semiconductor nanoclusters. Excited state and photosensitization aspects of rhodamine 6G H-aggregates bound to SiO{sub 2} and SnO{sub 2} colloids. United States: N. p., 1996. Web. doi:10.1021/jp9537724.
Nasr, C, Universite du Quebec a Trois Rivieres, Liu, D, Kamat, P V, & Hotchandani, S. Dye-capped semiconductor nanoclusters. Excited state and photosensitization aspects of rhodamine 6G H-aggregates bound to SiO{sub 2} and SnO{sub 2} colloids. United States. doi:10.1021/jp9537724.
Nasr, C, Universite du Quebec a Trois Rivieres, Liu, D, Kamat, P V, and Hotchandani, S. Thu . "Dye-capped semiconductor nanoclusters. Excited state and photosensitization aspects of rhodamine 6G H-aggregates bound to SiO{sub 2} and SnO{sub 2} colloids". United States. doi:10.1021/jp9537724.
@article{osti_282994,
title = {Dye-capped semiconductor nanoclusters. Excited state and photosensitization aspects of rhodamine 6G H-aggregates bound to SiO{sub 2} and SnO{sub 2} colloids},
author = {Nasr, C and Universite du Quebec a Trois Rivieres and Liu, D and Kamat, P V and Hotchandani, S},
abstractNote = {SiO{sub 2} and SnO{sub 2} colloids are capped with a cationic dye, rhodamine 6G, by electrostatic interaction. The close packing of these dye molecules on the negatively charged SiO{sub 2} and SnO{sub 2} colloid results in the formation of H-aggregates. These aggregates are nonfluorescent but can inject electrons from the excited state into SnO{sub 2} colloids. The photophysical and photochemical properties of rhodamine-6G-aggregate on SiO{sub 2} and SnO{sub 2} colloids have been investigated using picosecond laser flash photolysis. Charge injection from the excited dye aggregate into SnO{sub 2} nanocrystallites occurs with a rate constant of 5.5 x 10{sup 9} s{sup -1}. The application of these dye aggregates in extending the photoresponse of nanocrystalline SnO{sup 2} film has been demonstrated by constructing a photoelectrochemical cell. A maximum incident photon-to-photocurrent efficiency of nearly 1% was observed for the photosensitized current generation. Fast reverse electron transfer between the injected electron and the cation radical of the dye aggregate is a limiting factor in maximizing the incident photon-to-photocurrent efficiency (IPCE). 65 refs., 11 figs.},
doi = {10.1021/jp9537724},
journal = {Journal of Physical Chemistry},
number = 26,
volume = 100,
place = {United States},
year = {1996},
month = {6}
}