Abstract
Photoluminescence (PL) and time-resolved photoluminescence (TRPL) of the organic films that are composed of tris(8-hydroxyquinoline) aluminum (Alq3) as the host and 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H,[l]benzopyrano[6,7,8-ij]quinolizin-11-one (C545T) as the green dopant of different concentrations are measured. In TRPL measurements, we observe that the carrier lifetime decreases monotonically with increasing doping concentration. It may result from the more efficient energy transfer from the host to dopant and/or the higher absorption due to the concentration dependent quenching behaviors in the Alq3/C545T system. The time constant for energy transfer from the host to the dopant decreases with increasing doping concentration. However, it saturates when the doping concentration is higher than 2%. That means (1) the higher doping concentration has little contribution for C545T emission which is consistent with the steady state PL results, and (2) optical absorption plays an important role when the doping concentration exceeds 2%..
Keywords
Time-resolved photoluminescence, Concentration quench, Carrier dynamics.
Citation
TIEN-LUNG CHIU, CHIH-CHUNG TENG, CHIH-CHUNG YANG, JIUN-HAW LEE, Observation of dynamic energy transfer and quenching in doped tris(8-hydroxyquinoline) aluminum thin films with time-resolved photoluminescence spectroscopy, Optoelectronics and Advanced Materials - Rapid Communications, 4, 11, November 2010, pp.1913-1915 (2010).
Submitted at: May 19, 2010
Accepted at: Nov. 10, 2010