Delayed response to the photovoltaic performance in a double quantum dots photocell with spatially correlated fluctuation

A viable strategy for enhancing photovoltaic performance is to comprehend the underlying quantum physical regime of charge transfer in a double quantum dots(DQD) photocell. This work explored the photovoltaic performance dependent spatially correlated fluctuation in a DQD photocell. The effects of spatially correlated fluctuation on charge transfer and output photovoltaic efficiency were explored in a proposed DQD photocell model. The results revealed that the charge transport process and the time to peak photovoltaic efficiency were both significantly delayed by the spatially correlated fluctuation, while the anti-spatially correlated fluctuation reduced the output peak photovoltaic efficiency. Further results revealed that the delayed response could be suppressed by gap difference and tunneling coefficient within two dots. Subsequent investigation demonstrated that the delayed response was caused by the spatial correlation fluctuation slowing the generative process of noise-induced coherence, which had previously been proven to improve the quantum photovoltaic performance in quantum photocells. And the reduced photovoltaic properties were verified by the damaged noise-induced coherence owing to the anti-spatial correlation fluctuation and a hotter thermal ambient environment. The discovery of delayed response generated by the spatially correlated fluctuations will deepen the understanding of quantum features of electron transfer, as well as promises to take our understanding even further concerning quantum techniques for high efficiency DQD solar cells.

Inhibiting radiative recombination rate to enhance quantum yields in a quantum photocell

Inhibiting the radiative radiation is an efficient approach to enhance quantum yields in a solar sell.This work carries out the inhibition of radiative recombination rate(RRR)in a quantum photocell with two coupled donors.We perform explicit calculations of the transition rates,energy gaps and the absorbed solar wavelength-dependent RRR,and find that two different regimes play the crucial roles in inhibiting RRR.One is the quantum coherence generated from two different transition channels,the other includes the absorbed photon wavelength and gaps between the donor and acceptor in this proposed photocell model.The results imply that there may be some efficient ways to enhance the photoelectron conversion compared to the classic solar cell.

A new photosensitive neuron model and its dynamics

Biological neurons can receive inputs and capture a variety of external stimuli,which can be encoded and transmitted as different electric signals.Thus,the membrane potential is adjusted to activate the appropriate firing modes.Indeed,reliable neuron models should take intrinsic biophysical effects and functional encoding into consideration.One fascinating and important question is the physical mechanism for the transcription of external signals.External signals can be transmitted as a transmembrane current or a signal voltage for generating action potentials.We present a photosensitive neuron model to estimate the nonlinear encoding and responses of neurons driven by external optical signals.In the model,a photocell(phototube)is used to activate a simple FitzHugh-Nagumo(FHN)neuron,and then external optical signals(illumination)are imposed to excite the photocell for generating a time-varying current/voltage source.The photocell-coupled FHN neuron can therefore capture and encode external optical signals,similar to artificial eyes.We also present detailed bifurcation analysis for estimating the mode transition and firing pattern selection of neuronal electrical activities.The sampled time series can reproduce the main characteristics of biological neurons(quiescent,spiking,bursting,and even chaotic behaviors)by activating the photocell in the neural circuit.These results could be helpful in giving possible guidance for studying neurodynamics and applying neural circuits to detect optical signals.

Photoelectrochemical Properties of Bacteriorhodopsin Langmuir-Blodgett Films on ITO Conductive Electrode

Langmuir-Blodgett films containing bacteriorhodopsin were deposited on ITO conduc-tive electrodes.A sandwiched photocell with a junction structure of ITO/bR/electrolyte/ITO has beenconstructed,in which the bR LB film was directly put into contact with an aqueous electrolyte immobi-lized in an agar gel.Under visible light irradiation,the photocell produced a transient photocurrent due tothe change of light intensity,which characterized vision imitative material.A photoalarm device based ondifferential responsivity phenomena was fabricated.