Search

Three novel donor-acceptor-pi-acceptor-type compounds (WS5, WS6, and WS7) were synthesized and investigated in dye-sensitized solar cells (DSSCs) exploring the effect of conjugated linkers on device performance. The new dyes showed strong light-harvesting ability in the visible region with relatively high molar absorption coefficients (>21 800 M-1 cm(-1)).This can be attributed to their intrinsic charge transfer (CT) from the arylamine to the acceptor group. Density functional theory (DFT) calculations revealed a favorable lowest unoccupied molecular orbital (LUMO) energy level, allowing efficient injection into the semiconductor conduction band after excitation. Upon application in DSSC devices, the WS5 dye containing 4,7-di(furan-2-yl)benzo[c][1,2,5]thiadiazole as conjugated linker mediated the highest device power conversion efficiency (PCE) amounting to 5.5%. This is higher than that of the WS6-containing dye based on the 4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole linker (3.5%) and the WS7 dye based on the 4-(thiophen-2-yl)benzo[c][1,2,5]thiadiazole linker (4.3%) under AM 1.5 G illumination. The present results show furan-based dye linker systems to have a significant potential for improving DSSC efficiencies., QC 20201008

A series of porous silicon (PSi) samples was prepared using photoelectrochemical etching (PECE) method with optimum current density of 45 mA/cm2. The as-prepared PSi samples were characterized to determine the influence of the etching time (15, 25 and 30 min) on their morphology and electrical properties. The percentage of porosity was estimated via gravimetric analysis. The band gap of the fabricated PSi was ≈2.22 eV. Upon their use to fabricate metal-semiconductor-metal (MSM) ultraviolet photodetectors (UVPD), the fabricated PSi revealed excellent stability and reliability under repetitive shots at 530 nm. Furthermore, very fast rise time (≈0.28 s) was obtained at a bias of 1 V under visible light (530 nm) illumination.

A series of porous silicon (PSi) samples was prepared using photoelectrochemical etching (PECE) method with optimum current density of 45 mA/cm2. The as-prepared PSi samples were characterized to determine the influence of the etching time (15, 25 and 30 min) on their morphology and electrical properties. The percentage of porosity was estimated via gravimetric analysis. The band gap of the fabricated PSi was ≈2.22 eV. Upon their use to fabricate metal-semiconductor-metal (MSM) ultraviolet photodetectors (UVPD), the fabricated PSi revealed excellent stability and reliability under repetitive shots at 530 nm. Furthermore, very fast rise time (≈0.28 s) was obtained at a bias of 1 V under visible light (530 nm) illumination.

© 2017 American Chemical Society. Cesium-gold (Cs-Au) nanoparticles are shown to be analytically advantageous for the electroanalytical sensing of dapoxetine (DPX), a serotonin reuptake inhibitor used for the treatment of premature ejaculation. The Cs-Au nanoparticles are electrically wired and supported upon mass producible, economical screen-printed electrochemical sensing platforms and are characterized electrochemically (cyclic voltammetry and electrochemical impedance spectroscopy) and physiochemically (field emission scanning electron microscopy and energy dispersive X-ray analysis). The face-centered design was applied to optimize the significant experimental factors by using square wave voltammetry. The Cs-Au-based sensor is found to exhibit a large linear range (10 -7 to 10 -4 M) with a good analytical linearity with the limits of detection and quantification corresponding to 2.50 - 10 -10 and 8.33 - 10 -8 M, respectively. The developed sensor was successfully applied in the quantification of DPX in the presence of sildenafil, both of which are commonly found within combined dose tablet pharmaceutical formulations. The proposed DPX electrochemical Cs-Au-based sensor has the advantages of being single-shot and disposable and is shown to be successful in determining DPX in pharmaceutical formulations, human urine, and serum samples with acceptable recoveries.