In this paper, we investigate the carrier injection and transport characteristics in iridium(III)bis[4,6-(di-fluorophenyl)-pyridinato-N,C2']picolinate (FIrpic) doped phosphorescent organic light-emitting devices (OLEDs) with oxadiazole (OXD) as the bipolar host material of the emitting layer (EML). When doping Firpic inside the OXD, the driving voltage of OLEDs greatly decreases because FIrpic ...

A discrepancy is explored regarding the spin exchange integral estimated from magnetic field effects on recombination of the bacteriochlorophyll dimer cation (Bchl)(2)+ and the bacteriopheophytin anion Bph(-) and the measured electron transfer rate between Bph and electronically excited (Bchl)(2). In one explanation considered here there are two sites for the electron or for the hole, with a ho...

The Shockley-Read-Hall model for generation-recombination of electron-hole pairs in semiconductors based on a quasistationary approximation for electrons in a trapped state is generalized to distributed trapped states in the forbidden band and to kinetic transport models for electrons and holes. The quasistationary limit is rigorously justified both for the drift-diffusion and for the kinetic m...

Photoinduced electron transfer in a self-assembled supramolecular ladder structure comprising oligomeric porphyrin rails and ligated dipyridyltetrazine rungs was characterized by transient absorption spectroscopy and transient direct current photoconductivity to be mainly from an oligomer (rail) to the center of a terminal tetrazine (rung), with the remaining hole being delocalized on the oligo...

Cooperative spontaneous recombination (superfluorescence) of electron-hole plasmas in semiconductors has been a challenge to observe due to ultrafast decoherence. We argue that superfluorescence can be achieved in quantum-confined semiconductor systems and present experimental evidence for superfluorescence from high-density photoexcited electronhole plasmas in magnetized quantum wells. At a cr...

III-nitride light-emitting diodes (LEDs) suffer from a severe efficiency reduction with increasing injection current (droop). Auger recombination is often seen as primary cause of this droop phenomenon. The corresponding Auger recombination coefficient C is typically obtained from efficiency measurements using mathematical models. However, C coefficients reported for InGaN active layers vary ov...

The photocatalytic activity of materials for water splitting is limited by the recombination of photogenerated electron-hole pairs as well as the back-reaction of intermediate species. This review concentrates on the use of electric fields within catalyst particles to mitigate the effects of recombination and back-reaction and to increase photochemical reactivity. Internal electric fields in ph...

UNLABELLED In this paper, the performance of quantum dot-based light-emitting diodes (QLEDs) comprising ZnCdSe/ZnS core-shell QDs as an emitting layer were enhanced by employing Au-doped poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate ( PEDOT PSS) hole injection layer (HIL). By varying the concentration and dimension of Au nanoparticle (NP) dopants in PEDOT PSS, the optimal devices w...

PURPOSE The authors describe a detailed Monte Carlo (MC) method for the coupled transport of ionizing particles and charge carriers in amorphous selenium (a-Se) semiconductor x-ray detectors, and model the effect of statistical variations on the detected signal. METHODS A detailed transport code was developed for modeling the signal formation process in semiconductor x-ray detectors. The char...

A new ligand that covalently attaches to the surface of colloidal CdSe/CdS nanorods and can simultaneously chelate a molecular metal center is described. The dithiocarbamate-bipyridine ligand system facilitates hole transfer through energetic overlap at the inorganic-organic interface and conjugation through the organic ligand to a chelated metal center. Density functional theory calculations s...