An efficient nonfullerene acceptor for all-small-molecule solar cells with versatile processability in environmentally benign solvents

A new structure of dicyanodistyrylbenzene-naphthalimide-based nonfullerene acceptor NIDCSN was synthesized and characterized to have a favorable electron accepting property and versatile processability in various organic solvents. The nonfullerene all-small-molecule solar cells comprising p-DTS(FBTTh₂)₂ as the donor and NIDCSN as the acceptor exhibited a maximum power conversion efficiency of 3.45% with a remarkable open-circuit voltage of 1.04 V, together with similar device performances when fabricated in five different solvents including environmentally benign non-halogenated ones.     

Energetic distribution of interface states extracted from photo-conductance of organic thin film transistors

In this paper, a new method is introduced to obtain the energetic distribution of the interface states (density of states; DOS) extracted from the photo-conductance of organic thin film transistors (OTFTs) which exhibit varied transfer characteristics under illumination with different photon energies. The method was applied to pentacene OTFTs, and the results were compared with existing data. The major findings were not only the existence of the well-known peaks of DOS at 1.82 eV (free exciton of pentacene), and at 1.49 eV (extrinsic exciton due to dihydropentacene) but also new peaks were found at 1.25 eV, 1.29 eV, 1.31 eV, and 1.35 eV in the mid-gap. The new peaks were strongly enhanced under exposure to oxygen, and thus seem to be related to the defects associated with the presence of oxygen.     

Ni–Al composite hydroxides fabricated by cation–anion double hydrolysis method for high-performance supercapacitor

Chemical doping of nickel hydroxide with other cations(e.g. Al~(3+)) is an efficient way to enhance its electrochemical capacitive performances. Herein, a simple cation–anion(Ni~(2+)and AlO_2) double hydrolysis method was developed toward the synthesis of nickel–aluminum(Ni–Al) composite hydroxides. The obtained composite hydroxides possesses a porous structure, large surface area(121 m~2/g) and homogeneous element distribution. The electrochemical test shows that the obtained composite hydroxides exhibits a superior supercapacitive performances(specific capacitance of 1670F/g and rate capability of 87% from 0.5 A/g to 20 A/g) to doping-free nickel hydroxide(specific capacitance of 1227 F/g and rate capability of 47% from 0.5 A/g to 20 A/g). Moreover, the galvanostatic charge/discharge test displays that after 2000 cycles at large current density of 10 A/g, the composite hydroxides achieves a high capacitance retention of 98%, indicative of an excellent electrochemical cycleability.     

PEDOT electrodes for triboelectric generator devices

Triboelectric generators (TEGs) are devices that convert mechanical energy to electrical energy through triboelectric charging of different material surfaces at periodic contact. Typically, such devices consist of two dielectric contacting layers with electrodes attached on the non-contacting sides but alternatively, one material can simultaneously serve as both a contacting and an electrode material. In this work, we report the use of poly(3,4-ethylenedioxythiophene) (PEDOT) for TEG device were PEDOT film serves as both a contacting surface to PDMS and as an electrode. Two different PEDOT films were prepared on glass substrates by vapour-phase polymerization (VPP) and VPP combined with electropolymerization method and compared as TEG electrodes. Additionally, PEDOT/poly(1,6-hexanediol-co-citric acid) (PHC) composite films were prepared by using solution casting polymerization. These methods yielded PEDOT films with different morphology, surface roughness and conductivity. Best performance was demonstrated for the PEDOT film with the lowest surface roughness (1.88 nm RMS), prepared by VPP method, which generated peak current of 0.45 mA/m² and power density of 95 W/m², outperforming Sn doped In₂O₃ electrode approximately by threefold in the same experimental setup.     

Ultra-High Performance Liquid Chromatography with Electrospray Ionization Tandem Mass Spectrometry for the Determination of Caffeine in Energy Drinks

A simple and highly sensitive method for the determination of caffeine in energy beverages was developed and validated. Sample preparation utilizing solid-phase extraction (SPE) was simple and reliable. Separation by isocratic ultra-high performance liquid chromatography (UPLC) with a reversed-phase C₁₈ column was performed within 6 min. The use of SPE with UPLC coupled with electrospray ionization-multiple tandem mass spectrometry detection (ESI-MSⁿ) was accurate, reproducible, and validated for the determination of caffeine in energy drink matrices. The limit of quantification for caffeine was approximately 2.1 ng mL^?1. The intra-day and inter-day precisions were less than 4%, and the accuracy of the measurements was between 85.1% and 93.2%. Results for caffeine concentrations in eighteen beverages were compared to the values on the labels. This paper describes the first use of the UPLC–ESI-ion trap MSⁿ technique for quality-control purposes of caffeine present in energy drinks.     

Real-time quantification of Staphylococcusaureus in liquid medium using infrared thermography

We previously showed that infrared thermography (IRT) could be used to quantify viable Escherichiacoli, a representative gram-negative bacterium, in liquid growth media. Here, we evaluated the ability of IRT to enumerate a viable representative gram-positive organism, Staphylococcusaureus. We found that the energy content (EC) of the media was strongly positively correlated (r = 0.999) to measured viable counts of S.aureus ranging from 85 colony-forming units (CFU)/ml to ∼4 × 10⁸ CFU/ml. The EC of S.aureus was ∼2-fold higher than that of E.coli at comparable cell concentrations suggesting that IRT may be used to distinguish genera.     

硅橡胶包覆十八烷/聚(St-MMA)储能微胶囊复合材料制备及热性能

以十八烷/聚(苯乙烯-甲基丙烯酸甲酯)(P(St-MMA))微胶囊为相变材料,硅橡胶作为载体,制备了十八烷/P(St-MMA)/硅橡胶复合材料。研究了微胶囊的加入方式及加入量,硅橡胶包覆方法。通过红外光谱(IR)和扫描电镜(SEM)研究复合材料的结构和形貌。通过力学性能测试如拉伸强度、扯断伸长率,确定最佳的加工方法。通过热重分析法(TG)、差示扫描量热法(DSC)和储热性能对复合材料的热性能进行研究。结果表明,十八烷制成微胶囊加入到硅橡胶中,且微胶囊加入量是2份时,十八烷/P(St-MMA)微胶囊/硅橡胶的热稳定性热稳定性及力学性能较好。室温硅橡胶包覆微胶囊掺混固化法制备的复合材料的力学性能优于直接共混后热固化法和混炼涂抹后热固化法。十八烷/P(MMA-St)/硅橡胶复合材料的焓值为67.6J/g,储能效果好。     

Employing 4-methoxybenzoic acid interfacial-modification to enhance the photovoltaic performance of CdS quantum dot-sensitized solar cells

The effect of incorporating self-assembled monolayers of 4-methoxybenzoic acid (MBA) on CdS quantum dot-sensitized (QDSSC) solar cells based on ZnO nanorods was evaluated. The MBA was deposited on the ZnO photoanode, with the deposition time being a process variable. Photoluminescence spectra indicated that the MBA modification can suppress the photogenerated electron–hole recombination processes and presumably passivate the surface defects. The ultraviolet photoemission spectroscopy results prove that MBA forms an energy barrier at the interface of ZnO and CdS which may retard the back transfer of electrons. Overall the inclusion of MBA imparts a weak positive enhancement of the photovoltaic performance of these QDSSCs and this is an approach that may be developed to give stronger effects using alternative chemistries.     

Improving energy efficiency using a link adaptation algorithm dedicated for 100 Gbps wireless communication

This paper presents a link adaptation algorithm dedicated for 100 Gbps wireless transmission. Interleaved Reed-Solomon codes are selected as forward error correction (FEC) algorithms. The redundancy of the codes is selected according to the channel bit error rate (BER). The uncomplicated FEC scheme allows implementing a complete data link layer processor in an FPGA (field programmable gate array). In our case, we use the Virtex7 FPGA to validate the functionality of our implementation. The proposed FPGA-processor achieves 169 Gbps throughput. Moreover, the implementation is synthesized into 40 nm CMOS technology and the described link adaptation algorithm allows reducing consumed energy per bit to values below 1 pJ/bit at BER <1e−4. With higher BER, the energy increases up to ∼13 pJ/bit.     

Controlling the interface energetics of PCPDTBT by p-doping

The doping of organic semiconductors is a promising way for both improving the charge carrier transport and tuning the energy level alignment at interfaces. We study the influence of p-doping of the low band gap polymer PCPDTBT with F4-TCNQ on the energy level alignment in a prototype organic solar cell structure with ITO as an electrode material and the fullerene C₆₀ as electron acceptor material using Ultraviolet and X-ray photoelectron spectroscopy. As a consequence of the doping, a Quasi-Ohmic contact at the interface to ITO is formed, whereas the energy level alignment to C₆₀ is almost not affected. In contrast to a related system, we observe a depletion of the dopant at the polymer surface. The change of the energy level alignment only at the electrode interface might be advantageous for the application in organic solar cell devices.