Visualization of trap dilution in polyfluorene based light-emitting diodes

ZnO - Based Light - Emitting Diodes

Effects of polymer sidebranching in double- and single-layer polyfluorene light-emitting diodes

We study how changes in sidebranching in electroluminescent polymers affect the performance of polyfluorene-based light-emitting diodes with and without additional hole transport materials. We observe that light emission and device efficiency are determined more by the position of the exciton recombination zone than by changes in the polymer morphology induced by sidebranching. Consequently, we...

Tuning emission colors from blue to green in polymeric light-emitting diodes fabricated using polyfluorene blends.

The photo- and electroluminescent properties of single-layer two-component blends composed of one blue emitter polymer and one green emitter polymer were studied. The blue emitter, poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(9,9-di-{5'-pentanyl}-fluorenyl-2,7-diyl)] (PFOFPen), was used as the matrix, and the green emitter, poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(bithiophene)] (F6T2), was ...

InP-Based Cylindrical Microcavity Light-Emitting Diodes

We have investigated the properties of InP-based microcavity light-emitting diodes ( = 1 6 m). Our objective was mainly to study the effects of lateral confinement of optical modes, which was achieved by the wet oxidation of double In0 52Al0 48As layers. The smallest devices had a cavity radius of 0.5 m, which becomes comparable to where is the effective refractive index of the photon emitting ...

10 GaN - based Light - Emitting Diodes

Light-emitting diodes (LEDs) offer several advantages over traditional light sources, such as smaller size, longer lifetime, higher efficiency, and greater mechanical ruggedness. Continuing developments in LED technology are producing devices with increased output power and efficiency as well as a wider range of colors [1]. Recent progress in the fabrication of GaN-based compound semiconductors...