Photoelectric Behavior Research Articles

Anchored porphyrin with different side chain groups via its axial coordinate self-assembly for dye-sensitized solar cells

In this work, four anchored zinc porphyrins ZnPAi (i = 1–4) with different side chain substituent groups and antenna porphyrin ZnP1 have been designed, synthesized, and characterized. Anchored porphyrin ZnPAi (i = 1–4) and its self-assemblies formed by axial coordination with antenna porphyrin have been used as sensitizers in dye-sensitized solar cells. Our results indicate that cells based on self-assemblies exhibited obviously enhanced power conversion efficiency. In particular, the solar cells based on the zinc porphyrin (ZnPA2) with t-butyl side chain groups show higher conversion efficiency than that of other side chain porphyrin based devices. These results were also verified by optical performance, photocurrent conversion efficiency, and electrochemical impedance spectroscopy. In addition, the energy level and ground state geometric configuration of the dye were calculated, and the ultraviolet-visible absorption spectrum was simulated through density functional theory to further verify its photoelectric behavior.

Synthesis and Comparison of Properties of Single-Crystalline Bi13S18X2, and Fabrication of Solar Cells By Physical Vapor Deposition

Introduction As the global demand for energy is expected to grow rapidly, securing clean energy is essential for sustainable economic growth. Solar energy is the most promising clean energy source for the next-generation. One of the grand challenges in the field of photovoltaic materials is to find suitable materials which can produce high powder conversion efficiency, environmental-friendly and low cost. Recently, some V–VI–VII compounds (V = Sb, Bi; VI = O, S, Se; VII = Cl, Br, I) have attracted much attention as potential electronic materials. These compounds exhibit a variety of physical characteristics, including high photoconductivity, ferroelectric photovoltaic effects, piezoelectricity, electrooptical effects, and structural diversity.1 However, only a few of studies have been reported on Bi13S18X2 (X = Cl, Br, I) (BSX) compounds.2 Traditionally, these bismuth sulfohalogenides are synthesized using a vapor transport process and flux process under high temperature conditions over 600 oC. Herein, we reported a facile solvothermal process for the synthesis of bismuth sulfohalogenides Bi13S18X2 and systematic characterization of their photoelectric behavior as light absorbers for solar cells. A BSX-based solar cells, fabricated by PVD method, demonstrated a champion PCE of 1.15% for the first time, revealing the potential of BSX as a new type of light absorber material for solar cells. Experimental Typically, Bi13S18I2 (BSI) was synthesized by solvothermal reaction of BiI3 (2 mmol), MAI (MA = CH3NH3 +, 3 mmol), and a desired amount of CH4N2S in 5 mL of ethylene glycol solvent at desired temperature for 12 h. Similarly, Bi13S18Br2 (BSB) was synthesized by solvothermal reaction of BiBr3 (2 mmol), MABr (3 mmol), and a desired of CH4N2S under the same conditions. For Bi13S18Cl2 (BSC), BiCl3 (2 mmol) and a desired amount of CH4N2S were solvothermally treated in 5 mL of acetone solvent at desired temperature for 12 h. After reaction, the black solid products were filtered, washed with ethanol or acetone, and dried at 60 oC for 12 h.The TiO2 electrode was prepared on a FTO glass surface to obtain a FTO/TiO2 electrode. A FTO/TiO2/BSX electrode was fabricated by PVD of BSX on the FTO/TiO2 electrode using a thermal evaporator under vacuum conditions at current of 18 A for 30 seconds, where 200 mg of BSX bulk was used and FTO/TiO2 electrode was placed 8.0 cm above the BSX source. The obtained FTO/TiO2/BSX electrode was heated at desired temperatures under N2 atmosphere. An electrolyte solution of I3 -/I- redox couple was used as the hole-transporting material to constructed FTO/TiO2/BSI/(I-/I3 - solution)/Pt solar cells. Results and discussion Fig. 1(A) shows the XRD patterns of solvothermally synthesized BSX samples at 200 oC for 12h, which are single phases with high crystallinity. BSX are black crystals with a rod-like particle morphology. UV–vis-NIR spectrum results show that BSX has strong light absorption spanning from visible to near IR spectrum; the corresponding bandgaps of BSI, BSB and BSC are 0.87, 0.89 and 0.90 eV, respectively. The result suggests the potential application of BSX as a promising light absorber for solar cells. Fig. 1(B) shows the XRD patterns of FTO/BSX electrodes after heat treatment at 250 oC for 12 under N2 atmosphere. The XRD patterns suggest that single phases of crystalline BSX film can be obtained by heat treatment the PVD-fabricated films. Fig. 1(C) shows the cross-sectional and top-view FE-SEM images of FTO/TiO2/BSI electrode. A high quality BSI film, with a thickness of 350 nm was obtained. Fig. 1(D) exhibits the J-V curves of the BSX-based solar cells. The preliminary solar cells study results demonstrate PCE values of 0.67, 1.15 and 0.81% for BSI, BSB and BSC-based solar cells, respectively, revealing the potential of the BSX light absorber for a new type of solar cells that can be fabricated by a simple PVD method. References H. Koc, S. Palaz, A. M. Mamedov and E. Ozbay, Ferroelectrics, 2017, 511, 22-34.R. Groom, A. Jacobs, M. Cepeda, R. Drummey and S. E. Latturner, Chemistry of Materials, 2017, 29, 3314-3323. Figure 1

Facile Synthesis of In2S3 Modified Ag3PO4 Nanocomposites with Improved Photoelectrochemical Properties and Stabilities

In this work, Ag3PO4/In2S3 nanocomposites with low loading of In2S3 (5-15 wt %) are fabricated by two step chemical precipitation approach. The microstructure, composition and improved photoelectrochemical properties of the asprepared composites are studied by X-ray diffraction pattern (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photocurrent density, EIS and amperometric i-t curve analysis. It is found that most of In2S3 nanoparticles are deposited on the surfaces of Ag3PO4. The as-prepared Ag3PO4/ In2S3 composite (10 wt%) is selected and investigated by SEM and TEM, which exhibits special morphology consisting of lager size substrate (Ag3PO4), particles and some nanosheets (In2S3). The introduction of In2S3 is effective at improving the charge separation and transfer efficiency of Ag3PO4/In2S3, resulting in an enhancement of photoelectric behavior. The origin of the enhanced photoelectrochemical activity of the In2S3-modified Ag3PO4 may be due to the improved charge separation, photocurrent stability and oriented electrons transport pathways in environment and energy applications.

Measuring the Electrical and Photonic Properties of Cobalt Oxide-Containing Composite Carbon Fibers

In this work, cobalt acetate was incorporated into polyacrylonitrile (PAN) polymer through electrospinning as the cobalt oxide source. After oxidization and pyrolysis, a PAN-derived composite carbon fiber containing cobalt oxide was obtained. Measuring the electrical and photonic properties of the composite fiber under visible light irradiation was performed to evaluate the photoelectric behavior of the composite fiber. The p-type semiconducting behavior of the composite fiber was confirmed by measuring the open circuit voltage of a photochemical fuel cell consisting of the photosensitive electrode made from the composite fiber. The application of the composite fiber for glucose sensing was demonstrated.

TiO2-based dye-sensitized solar cells prepared with bixin and norbixin natural dyes: Effect of 2,2’-bipyridine additive on the current and voltage

In this paper, we discovered that the 2,2′-bipyridine (bipy) was able to increase the voltage and short circuit current of dye-sensitized solar cells (DSSCs) prepared using bixin and norbixin natural dyes that are environmentally friendly. Titanium oxide (TiO2) film was deposited on FTO-glass. Morphological analysis revealed that the film was porous and consisted of almost spherical particle with an average size of 35 nm. The photoelectric behavior of the DSSCs was evaluated under polychromatic radiation adjusted to 1.5 AM standard. The analysis revealed that the presence of bipy in the electrolyte significantly increased the open circuit voltage (VOC) values from 299 to 519 mV for the DSSCs prepared using bixin dye, whereas the VOC values increased from 293 to 311 mV for the DSSCs prepared using norbixin dye. Also, it was observed that the bipy additive positively influenced the short-circuit current (JSC) values of these devices. The simultaneous increase in VOC and JSC rendered this bipyridinic compound a good additive candidate for TiO2 nanoparticles-based DSSC using natural dyes.

Multi-shelled hollow cube CaTiO3 decorated with Bi12O17Cl2 towards enhancing photocatalytic performance under the visible light

It is highly desirable to combine the microstructure management and heterostructure construction technique to remold inherent wide band gap semiconductor CaTiO3 with the purpose of enhancing its visible light absorption capacity and photocatalytic performance. Herein, a novel multi-shelled hollow cube Bi12O17Cl2/CaTiO3 heterostructure has been successfully synthesized by a facile template-free method for photocatalytic hydrogen production and degradation pollutants in water under the visible light. The investigations of microstructure, physicochemical property and photoelectric behaviors indicate that the multi-shelled hollow cube architecture and synergetic effect of 2D-3D structural coupling are dominant reasons to enhance phototcatalytic performance, which can significantly improve the absorption and utilization of visible light, multiply abundant active radical generation and boost the separation and migration efficiency of photoproduced electron-hole pairs. Moreover, the probable photocatalytic reaction mechanisms, the feasible migration behaviors of photo-produced charges, the influence factors of enhancing photocatalytic activities are proposed in depth. It is intended that further innovative works on the multi-shelled hollow cube architecture design of high-performance photocatalyst by facile template-free hydrothermal method can be inspired.

Solvothermal growth of aligned SnxZn1-xS thin films for tunable and highly response self-powered UV detectors

In this study, well-aligned SnxZn1-xS (0 ≤ x ≤ 0.12 mol) nanostructured thin films were successfully grown on the glass substrate by a solvothermal method for ultraviolet detector applications. XRD results revealed a hexagonal wurtzite structure for all the SnxZn1-xS thin films. Through structural and morphological studies, as the Sn-content increases, the c-axis orientation became stronger. A comprehensive investigation of the morphological evolution also confirmed a considerable influence of Sn2+ incorporation on the growth mechanism and shape of the SnxZn1-xS nanostructures. The optical measurements indicated that as the Sn-content increases, a linear relationship between the band gap and Urbach energy was found, in which the band gap energy experienced a significant decrease from 4.20 to 3.83 eV; whereas the Urbach energy was dramatically broadened. A gradual increase was observed in the intensity of photoluminescence spectra, in which three prominent emission peaks were found, indicating a successful formation of the SnxZn1-xS nanostructures. The photosensing performance of the samples was studied for the first time. The ultraviolet detectors based on the Au/SnxZn1-xS thin film junctions featured an excellent rectification behavior and attractive photovoltaic effect under UVB exposure. The enhancing effects of annealing treatment on the photoelectric behavior of the samples were also noted. The photoresponse characteristics of the self-powered ultraviolet detectors exhibited a high Ion/Ioff ratio > 103 and a fast photoswitching speed with superior stability and reproducibility at zero voltage. Additionally, notable photosensitivity and detectivity of more than ∼20 times are achieved at the self-powered mode.

A DNA rolling motor for photoelectrochemical biosensing of oral cancer overexpressed 1

Herein, a photoelectrochemical (PEC) biosensor has been constructed depending on DNA rolling motor and the synergistic effect among graphene oxide (GO), hemin and DNA-templated silver nanoclusters (DNA-Ag NCs) for oral cancer overexpressed 1 (ORAOV1) detection. Target-triggered catalytic hairpin assembly (CHA) cycling strategy has been adopted for signal amplification. Because of the excellent photoelectric behaviors, the compounds of graphene oxide and hemin (GO/hemin) have been used as photoelectric material. DNA-Ag NCs have been employed as signal amplification labels to enhance PEC responses. Scanning electron microscopy (SEM) was used to record the morphologies of nanomaterials. PEC and electrochemical analytical methods were employed to investigate the stepwise modification of the constructed biosensor. As a result, the proposed sensing platform has exhibited excellent analytical performance to ORAOV1 in a linear range from 1.0 × 10−15 to 1.0 × 10-10 mol·L-1 with the detection limit of 3.3 × 10-16 mol·L-1. It can achieve sensitive detection of ORAOV1 in saliva samples. The sensing system not only shows good selectivity and remarkable stability, but also provides a new method for the prevention, early assessment and post-treatment of diseases.

Artificial synapses with photoelectric plasticity and memory behaviors based on charge trapping memristive system

Imitation of memory and learning behaviors of nervous system by nanoscale photoelectric devices is highly desirable for building neuromorphic systems or even artificial neural networks. In this work, artificial synapses with photoelectric plasticity and memory behaviors based on a charge trapping memristive system was fabricated. Versatile synaptic functions, such as photoelectric excitatory postsynaptic current behavior, short-term memory, long-term memory, short - to long-term memory transition, and photonic learning and forgetting behaviors, were all mimicked by applied pulses of light and electricity. Moreover, the device also has the potential to be used in flexible applications. The photoelectric plasticity and memory phenomenon can be attributed to charge trapping and detrapping, since the used CdSe/ZnS quantum dots with a quantum well structure that act as trapping centers. This work provides a cost-effective method to develop artificial synapse devices, neural networks, and computers with photoelectric operations.

A simple and efficient device configuration applicable in high-performance solar cells with limited material requirements

Efficient device configurations with simple structure and limited requirements for active materials, including quality and quantity, are of particular interest in solar cells. In this paper, a ‘U’ pool-shaped nanowall array is proposed and investigated regarding light management and photoelectric conversion behaviors based on gallium arsenide (GaAs). It was found that excellent omnidirectional light trapping can be realized in a broad structural parameter range. A photocurrent density (Jph) up to ~29.0 mA cm−2, i.e. ~93.5% absorption of incident photons with energy larger than 1.42 eV, i.e. the bandgap energy of GaAs is predicted at AM 1.5G illumination for the optimized array with an effective thickness of less than 350 nm. As a distinct comparison, a 2000 nm thick flat GaAs film only delivers Jph of ~19.8 mA cm−2 under the same illumination. Photoelectric simulations predict that to achieve a rationally high power conversion efficiency, bulk lifetime longer than 10−7 s for minority carriers in the base material, appropriate surface passivation of reducing the recombination velocity to the order of ~102 cm s−1 and contact resistance between electrodes and emitters lower than 10 Ω cm2 are required.

Reaction Spinning Titanium Dioxide Particle-Coated Carbon Fiber for Photoelectric Energy Conversion

In this paper, a titanium dioxide particle coated carbon fiber was prepared by reaction spinning. Polyacrylonitrile (PAN) was used as the precursor to generate a continuous carbon nanofiber. A solution containing 10% wt PAN polymer dissolved in dimethylformamide (DMF) was made as the core fluid. The sheath fluid contains 10% titanium (IV) isopropoxide, 85% ethanol, and 5% acetic acid. The two solutions were co-spun onto an aluminium plate covered with a layer of soft tissue paper. A titanium hydroxide layer formed at the surface of the PAN fiber through the hydrolysis of titanium isopropoxide due to the moisture absorption in the co-spinning process. The reaction spun fiber was converted to a partially carbonized nanofiber by the heat treatment in air at 250 °C for two hours, then in hydrogen at 500 °C for two hours. During the early stage of the heat treatment, the titanium hydroxide decomposed and produced titanium dioxide nanoparticles at the surface of the carbon fiber. The structure and composition of the carbonized fiber were studied by scanning electron microscopy (SEM). The photosensitivity of the particle-containing fiber was characterized by measuring the open circuit voltage under visible light excitation. The photoelectric energy conversion behavior of the fiber was confirmed by open circuit potential measurement. The potential applications of the composite fiber for photovoltaics and photonic sensing were discussed.

Electrochemical and Photoelectrochemical Characterization of Cu2SnSe3 Thin Films Deposited on Mo/Glass Substrates

Cu2SnSe3 (CTSe) thin films were fabricated by selenization of a Cu-Sn alloy, which was electrochemically co-deposited from a stirred citrate solution. Photoelectrical and optical properties of the obtained CTSe thin films were investigated by using only the electrochemical (we applied the cyclic voltammetry for determination the band gap of Cu2SnSe3 thin film semiconductor), photoelectrochemical and electrochemical impedance spectroscopy methods. New method is suggested, which allows to estimate the relationship between the etching time of secondary copper selenide phase and the photoelectrical properties (open circuit photopotential and photocurrent) of the CTSe thin films. The Cu2SnSe3 thin film with the best photo-response was obtained at a selenization temperature of 500°C. A significant improvement in photoelectrical behavior was observed on the CTSe thin film after 30 s of chemical etching in a 0.75 M KCN aqueous solution with the aim to remove the residual copper selenide phase. This film has a good photoelectrical and optical properties for solar cell formation: a p-type conductivity, a band gap of 0.92 eV, a carrier concentration Nα = 1.45 × 1017cm−3 and flat band potential EFB of 0.297 V vs. saturated hydrogen electrode and a photocurrent density of 0.44 mA × cm−2 at cathodic potential of −600 mV vs. saturated hydrogen electrode. A diagram of energy bands of the CTSe/electrolyte junction has been presented.

Synthesis, Crystal Structure, UV-Vis Adsorption Properties, Photoelectric Behavior, and DFT Computational Study of All-Inorganic and Lead-Free Copper Halide Salt K2Cu2Cl6.

In this study, all-inorganic copper halide salt K2Cu2Cl6 single-crystal and thin films were prepared. The single-crystal diffraction data belonged to the monoclinic K2Cu2Cl6 (space group = P2(1)/C, unit cell parameters of a = 4.0340 Å, b = 13.7987 Å, c = 8.7445 Å, α = 90.000, β = 97.123, and γ = 90.000). As far as we know, this is the first study of the copper halide salt K2Cu2Cl6 for optoelectronic applications. The band gap of K2Cu2Cl6 is calculated to be approximately 1.85 eV. A low-cost photodetector based on the K2Cu2Cl6 thin film was efficient under different monochromatic light from 330 to 390 nm with different chopping frequencies (1.33–30 Hz). Density functional theory (DFT) computational results indicate that the valence bands (VBs) and conduction bands (CBs) are shifted up in energy using the orbital-dependent correction to the DFT energy. Partial density of states reveals that the VBs and narrow CBs are derived from the hybrid orbitals of Cu2+ 3d and Cl– p, respectively.

Band-Gap Tuning of Organic-Inorganic Hybrid Palladium Perovskite Materials for a Near-Infrared Optoelectronics Response.

Organic–inorganic hybrid material is a recent hot topic in the scientific community. The best band gap for the entire solar absorption spectrum is about 1.1 eV. However, the lead perovskite band gap is about 1.5 eV. Therefore, developing organic–inorganic hybrid material toward the broader light harvesting of the solar spectrum is extremely urgent. In this study, we prepare three kinds of organic–inorganic hybrid palladium perovskite materials, including (CH3NH3)2PdCl4, (CH3NH3)2PdCl4–xBrx, and CH3NH3PdI3, for an optoelectronic response. The absorption cut offs of (CH3NH3)2PdCl4, (CH3NH3)2PdCl4–xBrx, and CH3NH3PdI3 are approximately 600, 700, and 1000 nm, respectively. The band gaps of (CH3NH3)2PdCl4, (CH3NH3)2PdCl4–xBrx, and CH3NH3PdI3 are determined to be approximately 2.15, 1.87, and 1.25 eV, respectively. To the best of our knowledge, this is the first study that discusses adsorption properties and photoelectric behavior of organic–inorganic hybrid palladium perovskite materials. Interestingly, the photoelectric response of the devices based on CH3NH3PdI3 reaches 950 nm. The results will attract attention in the fields of optical recorders, optical memory, security, light capture, and light treatment.

Alloying n-Butylamine into CsPbBr3 To Give a Two-Dimensional Bilayered Perovskite Ferroelectric Material.

Cesium-lead halide perovskites (e.g. CsPbBr3 ) have gained attention because of their rich physical properties, but their bulk ferroelectricity remains unexplored. Herein, by alloying flexible organic cations into the cubic CsPbBr3 , we design the first cesium-based two-dimensional (2D) perovskite ferroelectric material with both inorganic alkali metal and organic cations, (C4 H9 NH3 )2 CsPb2 Br7 (1). Strikingly, 1 shows a high Curie temperature (Tc =412 K) above that of BaTiO3 (ca. 393 K) and notable spontaneous polarization (ca. 4.2 μC cm-2 ), triggered by not only the ordering of organic cations but also atomic displacement of inorganic Cs+ ions. To our knowledge, such a 2D bilayered Cs+ -based metal-halide perovskite ferroelectric material with inorganic and organic cations is unprecedented. 1 also shows photoelectric semiconducting behavior with large "on/off" ratios of photoconductivity (>103 ).

Alloying n‐Butylamine into CsPbBr3 To Give a Two‐Dimensional Bilayered Perovskite Ferroelectric Material

AbstractCesium‐lead halide perovskites (e.g. CsPbBr3) have gained attention because of their rich physical properties, but their bulk ferroelectricity remains unexplored. Herein, by alloying flexible organic cations into the cubic CsPbBr3, we design the first cesium‐based two‐dimensional (2D) perovskite ferroelectric material with both inorganic alkali metal and organic cations, (C4H9NH3)2CsPb2Br7 (1). Strikingly, 1 shows a high Curie temperature (Tc=412 K) above that of BaTiO3 (ca. 393 K) and notable spontaneous polarization (ca. 4.2 μC cm−2), triggered by not only the ordering of organic cations but also atomic displacement of inorganic Cs+ ions. To our knowledge, such a 2D bilayered Cs+‐based metal–halide perovskite ferroelectric material with inorganic and organic cations is unprecedented. 1 also shows photoelectric semiconducting behavior with large “on/off” ratios of photoconductivity (>103).

Photoelectric Synergetic Responsive Slippery Surfaces Based on Tailored Anisotropic Films Generated by Interfacial Directional Freezing

AbstractSmart responsive slippery surfaces are highly desirable for their potential applications in many fields. Although slippery surfaces that respond to a single external stimulus are reported, challenges in fabricating synergetic responsive anisotropic slippery surfaces remain due to limitations in the preparation of the underlying anisotropic substrate. Here, photoelectric synergetic responsive slippery surfaces are fabricated based on anisotropic porous films that are tailored by using an interfacial directional freezing technique using a poly(3‐hexylthiophene‐2,5‐diyl)/[6,6]‐phenyl‐C61‐butyric acid methyl ester (P3HT/PCBM) binary system. The anisotropic surface structure of P3HT/PCBM films is facilely tailored by simply tuning the freezing speed, the P3HT/PCBM mass ratio, and the total concentration of solution. A detailed formation mechanism is proposed and elucidated. Moreover, anisotropic slippery surfaces demonstrate remarkable photoelectric synergetic behavior, which is used for the photoelectric synergetic control of droplet sliding and interfacial sentinel oxidative degradation. The in‐depth understanding of the formation mechanism of the anisotropic porous film may enable the interfacial directional freezing method to be extended to the design of other multifunctional anisotropic surfaces. This work will provide a theoretical basis for the design of new types of smart slippery surfaces, which are potentially useful in microfluidics, lab‐on‐chips, photoelectric displays, interfacial microreactors, and other related fields.

Fast charge separation and photocurrent enhancement on black TiO2 nanotubes co-sensitized with Au nanoparticles and PbS quantum dots

Reduced TiO2 nanomaterials (so-called black TiO2) attract intensive research interests due to their excellent capability for harvesting solar energy. To obtain a high conversion rate of solar energy to electrical energy, we loaded Au nanoparticles (NPs) and PbS quantum dots (QDs) on as-prepared TiO2 nanotubes (TNT) and black TiO2 nanotubes by magnetron sputter technique and subsequently dip coating for enhancing their photoelectric behaviors. It was discovered that the loadings of Au NPs and PbS QDs result in over 45% enhancement of photocurrent for the black TNT under visible light, and only ∼9.12% enhancement on the as-prepared TNT (without reduction process). The loadings of Au NPs and PbS QDs might act as separation centers rather than only light absorbers to accelerate electron-hole separation and transport. The black TiO2 nanotube composites could be considered as an excellent photoelectrode material applied in the field of solar energy conversion due to their high visible light harvesting and photoelectric response.

Stochastic electrical behavior of Splina liquid chlorophyll drink

Objective: To Study the photo-electric behavior of Spinacea pleracea by using the T.E-model of chlorophyll pigment. Methods/Statistical Analysis: The technic and method employed consisted on modeling the chlorophyll as an electrical circuit, to make a statistical analysis of electric conductance process of S. pleracea in light and in darkness by evaluating, the statistical average and statistical autocorrelation function, and make a temporal analysis by evaluating, the temporal average and temporal autocorrelation function. Finding: The electric conductance of Spinacea pleracea leaf plant increases when one passes from darkness to light; the spectral density of power (DSP) of the electric conductance process G(ω,t) under darkness is up to the DSP of the signal when S. pleracea is under light for the whole value of the reduced normalized frequency; the process is non-statistics in the broad sense (SSL) and non ergotic. The resemblance of the flow charge evaluated by autocorrelation functions for different values of the shift parameter is higher in light than in darkness. Application/Improvements: This study provided an additional tool to have an idea about the state of reactional center of photosystem II, knowing that the fluorescence emission testifies the loss of energy during the transfer of excitation to the reactional centers. In the same way, the electric conductance testifies the transfer of electrons released from the special chlorophyll ‘a’ of the reactional center to the photosynthetic channel. Keywords: Chlorophyll, Ergotic, Spectral Density of Power (DSP), Spinacea pleracea, Statistics in the Broad Sense (SSL)

One-step electrodeposition of high-quality amorphous molybdenum sulfide/RGO photoanode for visible-light sensitive photoelectrochemical biosensing

Exploiting high-quality photoactive material with visible light absorption, high photoelectrochemical (PEC) activity and stability is of great importance for developing high-performance PEC sensing. In this paper, amorphous molybdenum sulfide (a-MoSx)/reduced graphene oxide (RGO) hybrid film was directly grown on indium tin oxide (ITO) via a facile one-step electrodeposition, followed by a post annealing process. The uniform a-MoSx/RGO hybrid film exhibited significantly enhanced photocurrent, fast photoelectric switching behavior and robust stability under the visible light. Direct utilization of a-MoSx/RGO as an efficient photoanode for glucose determination had been demonstrated for the first time. Rapid response and robust stability for glucose determination in a wide linear range from 0.15 to 16 mM with a low detection limit were obtained. The reliability of detecting glucose in serum samples was demonstrated. This work stresses the importance of one-step electrodeposition preparation of a-MoSx/RGO hybrid film as high-quality photoanode for PEC bioanalysis.