Showing papers on "Chemical bath deposition published in 2019"

Cd-Free Cu(In,Ga)(Se,S) 2 Thin-Film Solar Cell With Record Efficiency of 23.35%

Abstract: In this article, the excellent properties of state-of-the-art Cd-free Cu(In,Ga)(Se,S)2 (CIGSSe) solar cells with Zn(O,S,OH) x /Zn0.8Mg0.2O double buffer layers, deposited by a combination of chemical bath deposition and atomic layer deposition techniques, are presented. By the replacement of conventional CdS buffer layers with this double buffer layer, the open-circuit voltage ( V oc) deficit of the devices could be significantly reduced, and V oc increased by approximately 15 mV. In addition, the fill factor and short-circuit current were also improved, increasing the device efficiency by approximately 0.5 absolute percent compared with devices with CdS buffers. The Cd-free double buffer layer improved the device efficiency regardless of the bandgap of the CIGSSe absorber. The minority carrier lifetime ( τ ) measured via time-resolved photoluminescence became longer, indicating that carrier recombination is mitigated using the double buffer layer. Based on the device parameters extracted by fitting the Suns– V oc characteristics to the double-diode model, the longer τ could be attributed to the decreased recombination rate in the space-charge region, rather than in the bulk and at the interface. The best performing cell was evaluated by a reliable third party, the National Institute of Advanced Industrial Science and Technology; this cell achieved a new world record efficiency of 23.35% for 1-cm2-sized thin-film polycrystalline solar cells. The device parameters of this cell are also discussed in this article.

Hierarchical Co3O4/CuO nanorod array supported on carbon cloth for highly sensitive non-enzymatic glucose biosensing

Abstract: A hierarchical core-shell Co3O4/CuO nanorod array (NRA) anchored on flexible carbon cloth (CC) has been fabricated through a stepwise process consisting of magnetron sputtering of Cu, its anodic oxidation, and chemical bath deposition of Co3O4. The structure, composition and morphology of the synthesized Co3O4/CuO NRA on CC were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The glucose sensing performance of the Co3O4/CuO NRA on CC electrode was investigated by cyclic voltammetry and chronoamperometry. The sensor exhibited a high sensitivity of 5405 μA mM−1 cm−2 with a fast response time (t90 = 1.9 s) and a low detection limit of 0.38 μM. The electrode also showed outstanding selectivity toward various interferences. These results indicate that the Co3O4/CuO nanocomposites may be promising electrode materials for electrochemical biosensing.

P-type Co3O4 nanoarrays decorated on the surface of n-type flower-like WO3 nanosheets for high-performance gas sensing

Abstract: Metal oxide heterostructures are significant materials for developing and improving various toxic gas detection sensors. However, the gas sensing performance, such as response, selectivity, stability and response/recovery time of the sensors, still need to be optimized for practical applications. Low dimensional heterostructures will improve the gas sensing performance remarkably. In this work, hierarchical cactus-like WO3/Co3O4 nanocomposites were directly deposited on the surface of ceramic tube via a simple two-step process. The p-type Co3O4 nanorods array were grown on the surface of n-type WO3 nanosheets by using chemical bath deposition (CBD) and thus many nanoscale p-n junctions were formed which greatly improved the gas sensing performance. A response value (Ra/Rg) of 6.19 to 1 ppm triethylamine (TEA) was achieved at 240 ℃ by the WO3/Co3O4 nanocomposite with the CBD deposition time of 30 min, which is 3 times higher than that of the pure WO3 nanosheets (Sr = 2.02). And the response/recovery time was about 13 s/152 s, which shows good gas sensing performance to TEA.

Interfacial Engineering by Indium-Doped CdS for High Efficiency Solution Processed Sb 2(S 1- x Se x) 3 Solar Cells

Abstract: Sb2(S1- xSe x)3 alloy material is a kind of encouraging material for realistically apposite solar cell because it benefits from high absorption coefficient, suitable bandgap, superior stability, and plentiful elemental storage. Interfacial engineering is vital for effective charge carrier transport in solar cells, which could upgrade the photoelectric conversion efficiency (PCE). Herein, as an interlayer, indium-doped CdS thin film fabricated by chemical bath deposition is found to remarkably enhance the photovoltaic performance of Sb2(S1- xSe x)3 solar cells. Mechanistic investigations show that the interlayer can both optically and electrically optimize the device quality. With that a PCE of 6.63% is obtained, which is the highest efficiency among the planar heterojunction solar cells and slightly higher than the reported record efficiency of mesoscopic Sb2(S1- xSe x)3-sensitized solar cells. This research provides an efficient interfacial engineering for high performance Sb2(S1- xSe x)3 solar cells.

Diffusion-Driven Al-Doping of ZnO Nanorods and Stretchable Gas Sensors Made of Doped ZnO Nanorods/Ag Nanowires Bilayers.

Abstract: A crystal-damage-free nanodoping method, which utilized the vacuum drive-in diffusion of Al into ZnO nanorods, was developed. In this method, vertical ZnO nanorod arrays that were grown by chemical bath deposition beforehand were deposited with Al thin film and subsequently heat-treated under a high vacuum. At an optimum condition, the surface Al atoms were completely diffused into ZnO nanorods, resulting in Al-doped ZnO nanorods. Stretchable gas sensors were fabricated by sequentially drop-casting the Al-doped ZnO nanorods and silver nanowires on polydimethylsiloxane substrate. The resistance and response of the sensor could be optimized through the elaborate control of relative densities of Al-doped ZnO nanorods and silver nanowires. The sensor showed a high response of 32.3% to 10 ppm of NO2 gas at room temperature, even under a large strain of 30%. The NO2-sensing mechanism of Al-doped ZnO nanorod/silver nanowire bilayer sensors is discussed on the basis of a synergistic interplay of Al-doped ZnO nanorods and silver nanowires.

Ni(OH) 2 @Ni core-shell nanochains as low-cost high-rate performance electrode for energy storage applications

Abstract: Energy storage performances of Ni-based electrodes rely mainly on the peculiar nanomaterial design. In this work, a novel and low-cost approach to fabricate a promising core-shell battery-like electrode is presented. Ni(OH)2@Ni core-shell nanochains were obtained by an electrochemical oxidation of a 3D nanoporous Ni film grown by chemical bath deposition and thermal annealing. This innovative nanostructure demonstrated remarkable charge storage ability in terms of capacity (237 mAh g−1 at 1 A g−1) and rate capability (76% at 16 A g−1, 32% at 64 A g−1). The relationships between electrochemical properties and core-shell architecture were investigated and modelled. The high-conductivity Ni core provides low electrode resistance and excellent electron transport from Ni(OH)2 shell to the current collector, resulting in improved capacity and rate capability. The reported preparation method and unique electrochemical behaviour of Ni(OH)2@Ni core-shell nanochains show potential in many field, including hybrid supercapacitors, batteries, electrochemical (bio)sensing, gas sensing and photocatalysis.

In Situ Growth of NiO@SnO2 Hierarchical Nanostructures for High Performance H2S Sensing

Abstract: Heterostructured metal oxides with large specific surface area are crucial for constructing gas sensors with high performance. However, using slurry-coating and screen-printing methods to fabricate...

Doping Efficiency in Cobalt-Doped ZnO Nanostructured Materials

Abstract: Nanostructured ZnO thin films doped with cobalt from 5% to 20% were grown on glass substrates by a low-temperature chemical bath deposition (CBD) technique. We compared the doping efficiency of incorporating cobalt in ZnO nanostructured samples doped with cobalt via cobalt nitrate and cobalt chloride. The concentration of cobalt incorporated into the ZnO matrix was precisely determined using inductively coupled plasma mass spectroscopy (ICP-MS). Scanning electron microscopy (SEM) images showed that only at a 0.1 M ratio of the precursor solutions in CBD using cobalt nitrate as a dopant, the morphology of ZnO yielded hexagonally shaped nanorods. At a 1 M ratio of the precursor solutions, SEM images showed that the morphology of ZnO was nanoplatelets at all doping levels, irrespective of the doping method used. The synthesized nanostructures retained the wurtzite hexagonal structure only at 0.1 M precursor solution using cobalt nitrate doping, which was confirmed by X-ray diffraction (XRD) studies. In cobalt-doped samples using cobalt chloride as a dopant, XRD analysis confirmed the formation of a Simonkolleite structure. At 300°C, the Simonkolleite structure was converted to a wurtzite structure without changing the morphology. Electrical conductivity measurements at 300 K showed that ZnO nanorods doped with cobalt using cobalt nitrate yielded the lowest resistivity. The molarity of the precursor solution and dopant was found to have a substantial impact on the morphology and doping efficiency of the ZnO nanostructures.

Defect-Rich ZnO Nanorod Arrays for Efficient Solar Water Splitting

Abstract: A novel ultrarapid synthetic method for the production of vertically aligned ZnO nanorod (NR) arrays has been demonstrated, using a microwave assisted chemical bath deposition method. High quality ...

TiO2 Coated ZnO Nanorods by Mist Chemical Vapor Deposition for Application as Photoanodes for Dye-Sensitized Solar Cells.

Abstract: In this study, a mist chemical vapor deposition method was applied to create a coating of titanium dioxide particles in order to fabricate ZnO/TiO2 core–shell nanostructures. The thin layers of titanium dioxide on the zinc oxide nanorods were uniform and confirmed as pure anatase phase. The morphological, structural, optical and photoluminescence properties of the ZnO/TiO2 core–shell structures were influenced by coating time. For instance, the crystallinity of the titanium dioxide increased in accordance with an increase in the duration of the coating time. Additionally, the thickness of the titanium dioxide layer gradually increased with the coating time, resulting in an increased surface area. The transmittance of the arrayed ZnO/TiO2 core–shell structures was 65% after 15 min of coating. The obtained ZnO/TiO2 core–shell nanostructures demonstrated high potentiality to serve as photoanodes for application in dye-sensitized solar cells.

Microflower-like nickel sulfide-lead sulfide hierarchical composites as binder-free electrodes for high-performance supercapacitors

Abstract: Nickel sulfide (NiS), lead sulfide (PbS) and composite of NiS-PbS hybrid are deposited onto nickel (Ni) foam current collector via a simple and cost-effective chemical bath deposition route and utilized as a binder-free battery-type electrode materials for supercapacitor applications. High-performance NiS and highly-stable PbS electrodes are rationally designed to develop a new class NiS-PbS electroactive material. Surface morphological and structural studies indicate that the NiS-PbS composite exhibits a beautiful morphology of nanosheet based microflower structures. Such hierarchical microflower structures provide abundant Faradic active sites and enable the fast redox reactions. As result, the NiS-PbS composite exhibits a higher specific capacity of 125.89 mA h g−1 at a current density of 2 A g−1 in 3 M KOH electrolyte solution, and it is 1.62 and 2.67 times higher than the bare NiS and PbS electrodes. In addition, NiS-PbS composite delivers excellent cycling stability retaining 88.97% of initial capacitance after 3000 cycles, which is much larger than that of NiS (76.86%) and PbS (82.72%) electrodes. Our results demonstrate that the microflower structured NiS-PbS composites are promising for supercapacitor applications.

Efficient Solar Cells Employing Light-Harvesting Sb 0.67 Bi 0.33 SI

Abstract: Sb1- x Bix SI, an isostructural material with the well-known quasi-1D SbSI, possesses good semiconductive and ferroelectric properties but is not applied in solar cells. Herein, solar cells based on alloyed Sb0.67 Bi0.33 SI (ASBSI) as a light harvester are fabricated. ASBSI is prepared through the reaction of bismuth triiodide in N,N-dimethylformamide solution with an antimony trisulfide film deposited on a mesoporous (mp)-TiO2 electrode via chemical bath deposition at 250 °C under an argon or nitrogen atmosphere; the alloy exhibits a promising bandgap (1.62 eV). The best performing cell fabricated with poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] as the hole-transporting layer shows 4.07% in a power conversion efficiency (PCE) under the standard illumination conditions of 100 mW cm-2 . The unencapsulated cells exhibit good comprehensive stability with retention of 92% of zjr initial PCE under ambient conditions of 60% relative humidity over 360 h, 93% after 1 sun illumination for 1254 min, and 92% after storage at 85 °C in air for 360 h.

Machine Learning Optimization of p-Type Transparent Conducting Films

Abstract: p-Type transparent conducting materials (p-TCMs) are important components of optoelectronic devices including solar cells, photodetectors, displays, and flexible sensors. Cu–Zn–S thin films prepare...