Charge transfer (CT) states play a key role in the functioning of organic solar cells; however, understanding mechanism by which CT dissociate efficiently into free charges remain conceptual challenge. Here, electric field dependent dynamics charge generation planar cyanine/fullerene photovoltaic cells is probed over wide temperature range using time-resolved Stark effect experiments, transient...

Doping a semiconductor can extend the light absorption range, however, it usually introduces mid-gap states, reducing the charge carrier lifetime. This report shows that doping lanthanum dititinate (La2Ti2O7) with nitrogen extends the valence band edge by creating a continuum of dopant states, increasing the light absorption edge from 380 nm to 550 nm without adding mid-gap states. The dopant s...

The phase noise of quantum dot lasers is investigated theoretically by coupling the Langevin noise sources into the rate equations. The off-resonant populations in the excited state and in the carrier reservoir contribute to the phase noise of ground-state emission lasers through the phase-amplitude coupling effect. This effect arises from the optical-noise induced carrier fluctuations in the o...

background and objective: staphylococcus aureus is an important infection in hemodialysis patients. we studied the prevalence of nasal carriage of methicillin-resistant staphylococcus aureus (mrsa) and its antibiotic resistance pattern in patients receiving hemodialysis as well as in dialysis unit staff. materials and methods: from june to september 2012, we evaluated 74 cases including 61 pati...

Models for the carrier photoexcitation mechanism in molecular crystals have been established initially on the bases of measurements on oligoacenes and later applied to conjugated polymers as well. These models emphasize the localized nature of photoexcitations and describe carrier generation as a secondary process involving exciton dissociation. The results of our photoconductivity studies of s...

We report on direct evidence of ultrafast carrier dynamics displaying features on the picosecond time scale in microcrystalline silicon (mc-Si:H). The dynamics of photogenerated carriers is studied by using above-band-gap optical excitation and probing the instantaneous carrier mobility and density with a THz pulse. Within the first picoseconds after excitation, the THz transmission transients ...

It is shown that interface trap states have pronounced effects on carrier transport and parameter extraction from top-gated InAs nanowire field effect transistors NWFETs . Due to slow surface state charging and discharging, the NWFET characteristics are time dependent with time constants as long as 45 s. This is also manifested in a time-dependent extrinsic transconductance that severely affect...

Planar diodes fabricated with nano-structured silver oxide thin film show resistive switching effects. These structures can be programmed by voltage into two distinct resistive states and they are promising candidates for resistive random access memory (RRAM) devices. Cycle endurance on/off ration and charge retention are high. This wok provides insight into the mechanisms leading to the memory...

With the help of a simple quantum key distribution (QKD) scheme, we discuss the relation between BB84-type protocols and two-step-type ones. It is shown that they have the same essence, i.e., information-splitting. More specifically, the similarity between them includes (1) the carrier state is split into two parts which will be sent one by one; (2) the possible states of each quantum part are ...

We report the carrier dynamics in GaAsSb ternary alloy grown by molecular beam epitaxy through comprehensive spectroscopic characterization over a wide temperature range. A detailed analysis of the experimental data reveals a complex carrier relaxation process involving both localized and delocalized states. At low temperature, the localized degree shows linear relationship with the increase of...