Electric-field-induced optical second-harmonic generation in ž / poly phenylene vinylene light-emitting diodes

Comment on "triplet-to-singlet exciton formation in poly(p-phenylene-vinylene) light-emitting diodes".

The triplet to singlet exciton formation ratio in a MEH-PPV light-emitting diode is measured by comparing the triplet-induced absorptions with optical and electric excitations at the same singlet exciton density. The ratio is a strong universal decreasing function of the averaged electric field. Using 4 ns for singlet to triplet intersystem crossing time, the ratio is significantly larger than ...

Hole blocking in carbon nanotube–polymer composite organic light-emitting diodes based on poly (m-phenylene vinylene-co-2, 5-dioctoxy-p-phenylene vinylene)

Contact Injection into Polymer Light-Emitting Diodes

The variation of current I with voltage V for poly(phenylene vinylene) and other polymer light-emitting diodes has been attributed to carriers tunneling into broad conduction and valence bands. In actuality the electrons and holes tunnel into polaron levels and transport is by hopping among these levels. We show that for small injection the I-V characteristic is determined mainly by the image f...

Detection of Pre-electrical Breakdown of IZO/-NPD/Alq3/Al Light-emitting Diodes by Electric-field-induced Optical Second-harmonic Generation Measurement

By using the electric-field-induced optical second-harmonic generation (EFISHG), we measured the EFISHG-time (EFISHG-t) characteristics to study pre-electrical breakdown of indium-zinc-oxide (IZO)/ N,N'-di [(1-naphthyl)-N,N'-diphenyl]-(1,1'-biphenyl)4,4'-diamine (-NPD)/ tris(8-hydroxy-quinolinato)aluminum(III) (Alq3)/Al organic light-emitting diodes (OLEDs). A series of EFISHG pulses were iden...

Improved efficiencies in organic light emitting diodes made with CdSe/ZnS quantum dots and a semiconducting polymer.

In this study, we report the fabrication and characterization of organic/inorganic hybrid polymer light emitting diodes (PLEDs) made with ZnS-capped CdSe core/shell type nanocrystals and a light-emitting polymer poly[2-phenyl-3-(9,9-dihexylfluoren-2-yl)-1,4-phenylene vinylene]-co-[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene]. The device using pristine polymer as active layer emitted y...