Papers by Keyword: Forster Energy Transfer

Abstract: The effect of laser dye (Fluorol 7GA) content on the optoelectronic properties of Poly ( 9,9'-di-n-octylfluorenyl-2.7-diyl) conjugated polymer (PFO) based OLEDs has been investigated. The PFO/Fluorol 7GA hybrids with weight ratios between 0.1 and 5 wt. % were prepared using the solution blending method. The blends were deposited on ITO (Indium Tin Oxide) substrate using spin-coating technique. Thin layer of aluminum was deposited on top of the films to act as electrode. Absorption and photoluminescence techniques were used to investigate the energy transfer in the blend. The device performance was investigated in terms of electroluminescence, luminance, luminance efficiency and color measurements. The Förster energy transfer occurred in the blends as evidence from optical spectroscopy and average distance between donor and acceptor molecules. The optimum ratio was 0.5 wt. % where highest enhancement in OLEDs performance was observed. These were attributed to the synchronize effect of efficient energy transfer from PFO to Fluorol 7GA and carrier trapping processes.

Abstract: In this paper, we studied lasing action in dual-doped organic microcavity with cascade Forster energy transfer between polymer and two fluorescent dyes in surface emitting microcavities, which formed by sandwiching a poly(N-vinylcarzole) (PVK) film doped with 8-trishydroxyquinoline (Alq3) and 4-(dicyanomethylene)-2-tert-butyl-6 (1, 1, 7, 7-tet ramethyljulolidyl-9-enyl)-4H–pyran (DCJTB) between a distributed Bragg reflector (DBR) and a silver film mirror. The sample was optically pumped by a frequency-tripled Nd:YAG laser delivering 5.55ns pulses at 355nm with a 10Hz repetition rate. By optimizing the concentrations of Alq3 and DCJTB in PVK, a low lasing threshold of about 9.5µJ per pulse attributed to efficient cascade Forster energy transfer form PVK and Alq3 to DCJTB was obtained. The full width at half maximum (FWHM) of the emission was about 2nm with the peak wavelength at 628nm. Our results demonstrate that the PVK:Alq3:DCJTB could be a promising candidate as gain medium for red organic diode lasers.