Although bonding networks determine electron-transfer (ET) rates within proteins, the mechanism by which structure and dynamics influence ET across protein interfaces is not well understood. Measurements of photochemically induced ET and subsequent charge recombination between Zn-porphyrin-substituted cytochrome c peroxidase and cytochrome c in single crystals correlate reactivity with defined ...

The influence of solvent additives on the temperature behavior of both charge carrier transport and recombination kinetics in bulk heterojunction solar cells has been investigated by electric noise spectroscopy. The observed differences in charge carrier lifetime and mobility are attributed to a different film ordering and donor-acceptor phase segregation in the blend. The measured temperature ...

In the present study, random current fluctuations measured at different temperatures and for different illumination levels are used to understand the charge carrier kinetics in methylammonium lead iodide CH3NH3PbI3-based perovskite solar cells. A model, combining trapping/detrapping, recombination mechanisms, and electron-phonon scattering, is formulated evidencing how the presence of shallow a...

In this paper, the study of the recombination of non-equilibrium charge carriers and determination of recombination mechanisms in Ge/Si heterostructures with nanoislands have been presented. The effects of long-term photoconductivity decay in Ge/Si heterostructures with Ge nanoislands have been found as caused by variations of the electrostatic potential in the near-surface region of Si(100) su...

Transient absorption spectroscopy on subpicosecond to second time scales is used to investigate photogenerated charge carrier recombination in Si-doped nanostructured hematite (α-Fe2O3) photoanodes as a function of applied bias. For unbiased hematite, this recombination exhibits a 50% decay time of ~6 ps, ~10(3) times faster than that of TiO2 under comparable conditions. Anodic bias significant...

The power conversion efficiency of photovoltaic cells based on the use of hybrid halide perovskites, CH3NH3PbX3 (X = Cl, Br, I), now exceeds 20%. Recently, it was suggested that this high performance originates from the presence of ferroelectricity in the perovskite, which is hypothesized to lower charge recombination in the device. Here, we investigate and quantify the influence of mesoscale f...

Investigation of charge transfer dynamics in dye-sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this ...

Experimental investigations of photoinduced charge transport in synthetic DNA capped hairpins possessing electron acceptor and donor stilbene chromophores at either end have established the mechanism, dynamics, and efficiency of charge transport in DNA. The mechanism for charge transport in repeating A-T base pairs (A-tracts) was found to change from single-step superexchange at short distances...

Ultrafast optical spectroscopy was utilized to investigate charge transfer dynamics across organic semiconductor tetracene/C60 interfaces in the presence of a LiF barrier layer. Photoinduced absorption spectra in the 1.6−2.3 eV range reveal a strong effect of the intermediate LiF barrier layer on dynamics of the charge transfer excitons (CTE) creation and recombination. Increasing thickness of ...

The ultimate efficiency of organic solar cells (OSC) is under active debate. The solar cell efficiency is calculated from the current-voltage characteristic as a product of the open-circuit voltage (VOC), short-circuit current (JSC), and the fill factor (FF). While the factors limiting VOC and JSC for OSC were extensively studied, the ultimate FF for OSC is scarcely explored. Using numerical dr...