• Media type: E-Article
  • Title: Frequency up-conversion as a temperature probe of organic opto-electronic devices
  • Contributor: Lupton, John M.
  • Published: AIP Publishing, 2002
  • Published in: Applied Physics Letters, 80 (2002) 2, Seite 186-188
  • Language: English
  • DOI: 10.1063/1.1432766
  • ISSN: 0003-6951; 1077-3118
  • Keywords: Physics and Astronomy (miscellaneous)
  • Origination:
  • Footnote:
  • Description: Frequency up-conversion is demonstrated in a polyfluorene-based conjugated polymer. Up-converted emission is observed upon excitation to the red of the 0-0 luminescence band. The emission intensity depends strongly on temperature and provides an accurate probe of the operating temperature of organic light-emitting diodes. Temperature rises of up to 30 K are observed at standard operating current densities of 225 mA/cm2. Due to the low thermal conductivity and heat capacity of the polymer film, the temperature of the film is found to rise slowly on a time-scale of seconds. Upon termination of the current, the temperature decreases again on a time-scale of minutes.