ISSN:
1432-0649
Keywords:
42.80
;
35
;
07
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We describe an extremely sensitive method to investigate nonradiative processes following optical excitation. In a low-temperature calorimeter, the sample is irradiated with monochromatic light. The absorbed energy which is converted into phonons leads to a measurable increase of the sample temperature. The lowest detectable dissipated energy is 2·10−12J at a working temperature of 0.03 K. We demonstrate our method with a calorimetric absorption spectrum of J-aggregate monolayers of 1-methyl-1′-octadecyl-2,2′-cyanine. From this spectrum the emission quantum efficiency is obtained as a function of excitation wavelength. A relative minimum is found at the long wavelength edge of the absorption band at 582.5 nm.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00697484
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