- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Synthesis of brass nanowires and their use for organic photovoltaics
摘要： Preponderant electric conductivity, high transmittance properties, and large natural abundance of its main component are striking features of copper nanowire (Cu NW)-based thin films. Because they are easily synthesized via low-cost solution-based processes, copper nanowires are considered an affordable next-generation conductor for transparent electrodes. Copper nanowire applications are expected to become more popular over the next decade. However, copper nanowire itself has a tremendously high surface-to-volume ratio and an abundance of surface atoms which lead to its high reactivity with the external environment. This reactivity presents a challenge for the improvement the long-term stability of copper nanowires, as it directly affects their applications. This novel study demonstrates a process to protect copper nanowires with an ultrathin stable brass layer-Cu/Brass NWs. The final product exhibited a high performance comparable to commonly used electrodes with a low sheet resistance of 30 Ω/sq at 89% transparency. Moreover, the Cu/Brass NWs resisted oxidation corrosion as the amplitude resistance fluctuated only around 3 Ω/sq for 30 days. For performance verification, an organic solar cell was fabricated using a Cu/Brass NW-based transparent electrode. It yielded an efficiency of 5.85%, reaching nearly that of a conventional cell using indium tin oxide. This demonstrates that Cu/Brass NWs are very promising for future application in low-cost optoelectronic devices.
关键词： Transparent electrode,Copper nanowire,Copper/brass nanowires,Electroless Zn plating,Organic solar cell
更新于2025-09-23 15:19:57
-
CuIn-ethylxanthate a a??versatile precursora?? for photosensitization of graphene-quantum dots and nanocatalyzed synthesis of imidazopyridines with ideal green chemistry metrics
摘要： Recently, the development of hybrid nano catalyst involving earth abundant transition metals for photosensitization and multi-component reaction in industry and academia has been a matter of intense study. Such hybridized catalytic systems minimize the production cost and acts as a bridged system by diversifying the application in different areas. In the present study copper indium ethylxanthate was used as a versatile precursor for synthesis of colloidal chalcopyrite phase copper indium sulphide (CC-CIS NPs) in photosensitization of graphene quantum dots and reusable powdered wurzite phased copper indium sulphide nanoparticles (PW-CIS500 NPs) for selective and efficient single pot sustainable synthesis of substituted imidazopyridines via A3 coupling strategy of an aldehyde, amine and alkyne. The material was characterized by various spectroscopic techniques viz HR-TEM, PXRD, FESEM, elemental mapping studies, UV visible spectroscopy, photoluminescence, XPS, BET and ICP-OES/MS etc. Quenching of photoluminescence intensity of colloidal CuInS2 on anchoring the graphene quantum dots (GQDs) was confirmed by photosensitization of GQDs via efficient charge transfer in CIS-GQD interface. On the other hand, the PW-CIS500 NCs catalyzed A3 coupling strategy demonstrates the high catalytic efficiency for A3 coupling reaction giving substituted imidazopyridines without losing its activity and could be recycled with a total turnover number of > 210, good E-factor of 0.13 and high RME of 88%.
关键词： multicomponent reactions,heterogenous catalysis,copper indium sulphide,copper indium ethylxanthate,imidazopyridines,graphene quantum dots,charge transfer
更新于2025-09-23 15:19:57
-
Optimum reproduction and characterization of graphene on copper foils by low pressure chemical vapor deposition
摘要： Although the chemical vapor deposition synthesis of scalable graphene was done by many different groups, growing mechanism and optimization of graphene on copper foils has not yet been fully understood under appropriate conditions. In the context of low pressure chemical vapor deposition, annealing of copper can lead to very large and flat grains for uniform formation of monolayer graphene on copper via a combination of H2 and CH4 gases at a substrate temperature of 1000°C. Growing tendency of graphene domains was investigated according to different exposure time and flux of CH4. Graphene was found not to be a uniform coverage of the whole copper surface due to inhomogeneous surface roughness among different copper grains. However, it can be improved more significantly by annealing copper up to near its melting temperature before graphene formation at lower substrate temperature of 1000°C. For this reason, we found that the thermal resistance of our materials acts as a function of the degree of graphene coverage on copper. Our graphene on copper foils was investigated by optical microscopy, Raman spectroscopy, scanning electron microscopy and heat transfer technique.
关键词： Thermal resistance,Interface,Copper foils,LPCVD graphene,Graphene on copper
更新于2025-09-23 15:19:57
-
Utility of copper oxide nanoparticles (CuO-NPs) as efficient electron donor material in bulk-heterojunction solar cells with enhanced power conversion efficiency
摘要： In the present work, we have endeavored the utilization of wet-chemically synthesized copper oxide nanoparticles (CuO-NPs) as the active layer in hybrid bulk heterojunction (BHJ) solar cells. The BHJs with CuO-NPs display significantly different physics from customary BHJs, and prove a noteworthy improvement in their performance. It is noted that with the addition of CuO-NPs, the morphology of the photoactive layer endures significant changes. Incorporating CuO-NPs is an additional paradigm for BHJs solar cells which enhances the photocurrent density from 9.43 mA/cm2 to 11.32 mA/cm2 and the external quantum efficiency as well. Also the power-conversion efficiency (PCE) improved from 2.85 % to 3.82 % without harming the open circuit voltage and the fill factor. The enhancement in PCE achieved here makes it worthy to design high-performance organic solar cells holding inorganic nanoparticles.
关键词： thin films,Bulk heterojunction,Solar cells,external quantum efficiency,Copper oxide nanoparticles,photo current density
更新于2025-09-23 15:19:57
-
Large-area grain-boundary-free copper films for plasmonics
摘要： Ultrasmooth single-crystalline metallic thin films provide several key advantages for the fabrication of well-defined and high-resolution plasmonic nanostructures, particularly complex integrated nanocircuits. For this purpose, copper is generally regarded as a poor plasmonic material compared to gold and silver because of its notorious oxidation issues when subjected to air exposure. Here, we report on the use of large-area grain-boundary-free copper films grown epitaxially on sapphire substrates in combination with focused ion beam milling to pattern plasmonic nanostructures with superior quality. The copper surfaces prepared using a single-crystalline copper sputtering target exhibit a very low roughness without any grain boundaries for varying film thicknesses and a strong resistance to oxidation, overcoming the bottleneck in conventional copper film fabrication. Surface plasmon resonance measurements show that improved dielectric constants with higher conductivity and long-term stability can be achieved using the single-crystalline copper films. Plasmonic nanohole arrays patterned from these high-quality films are found to display a stronger field enhancement compared to those made from polycrystalline copper films, thus resulting in an enhanced extraordinary optical transmission performance. This study suggests that our fabrication method is ideally suited for applications in copper-based plasmonic and nanophotonic devices as well as integrated nanocircuits on a large scale.
关键词： Single-crystalline films,Polycrystalline films,Surface plasmon resonances,Copper,Extraordinary optical transmission
更新于2025-09-23 15:19:57
-
Fabrication of flexible and bifacial Cu(In,Ga)Se2 solar cell with superstrate-type structure using a lift-off process
摘要： Flexible and bifacial Cu(In,Ga)Se2 (CIGS) solar cell with superstrate-type structure utilizing ethylene tetra-fluoroethylene (ETFE) was fabricated by a lift-off process. The advantages of the lift-off process performed under low temperature (below 100 °C) are to allow to deposit the CIGS layer under high temperature and to use ETFE as superstrate. The superstrate-type structure consists of ETFE/epoxy glue/ZnO:Al (AZO)/ZnO/CdS/CIGS/back contact, where the bilayer of ultra-thin 5-nm-thick Au/400-nm-thick AZO was used as the back contact. The optical and electrical properties of the bilayer of ultra-thin Au/400-nm-thick AZO were examined for the suitable back contact. It is determined that the transmittance of the bilayer of the ultra-thin 5-nm-thick Au/AZO is reasonably suitable in view of optical property. The ohmic-like characteristic at the CIGS/ultra-thin 5-nm-thick Au/AZO interface is attained. Consequently, the flexible and bifacial CIGS solar cell is realized by a lift-off process with conversion efficiency values of 6.2% for the frontside illumination and 0.9% for the backside illumination.
关键词： ETFE film,Superstrate-type structure,Flexible and bifacial solar cell,Copper indium gallium selenide,Lift-off process
更新于2025-09-23 15:19:57
-
Liquid State and Zombie Dye Sensitized Solar Cells with Copper Bipyridine Complexes Functionalized with Alkoxy Groups
摘要： Copper redox mediators can be employed in dye sensitized solar cells (DSCs) both as liquid electrolyte or as solid state hole transport materials (HTMs). The solid state devices, employing copper complex HTMs can be simply obtained by solvent evaporation in liquid state devices. During this evolution, the copper complex molecules present in the electrolyte solvent slowly aggregate in the pores of the TiO2 film and they also close the gap between the TiO2 film and counter electrode. However, the crystallization of the HTM infiltrated in the mesoscopic TiO2 pores can lead to low photovoltaic performance. In order to prevent this problem, we designed two copper redox mediators [Cu(beto)2]1+ (beto=4,4’-diethoxy-6.6’-dimethyl-2,2’-bipyridine) and [Cu(beto2Ox)2]1+ (beto2Ox=4,4’-bis(2-methoxyethoxy)-6,6’-dimethyl-2,2’-bipyridine) with extended side chains. Firstly, we studied these complexes in liquid state devices in reference to the [Cu(tmby)2]2+/1+ complex (tmby = 4,4?,6,6?- tetramethyl-2,2?-bipyridine). The solar-to-electrical power conversion efficiencies for liquid state devices, were over 10% for all of the complexes by using the organic Y123 dye under 1000 Wm-2 AM1.5G illumination. However, solid state devices showed significantly diminished charge transport properties and short circuit current density values even though the crystallization is reduced.
关键词： Hole transport materials,Dye sensitized solar cells,Crystallization,Photovoltaic performance,Copper redox mediators
更新于2025-09-23 15:19:57
-
Laser sintering of Cu@Ag core-shell nanoparticles for printed electronics applications
摘要： Bimetallic Cu@Ag core-shell nanoparticles (NPs) were synthesized by the reduction of copper 2-[2-(2-methoxyethoxy)ethoxy]acetate with hydrazine hydrate in benzyl alcohol followed by the reduction of silver ions on the copper surface using a galvanic replacement reaction. Ink consisting of the as-synthesized Cu@Ag NPs dispersed in a mixture of nontoxic solvents with different boiling temperatures (butanol and propylene glycol ethers) was prepared. Thin layers were spin coated on polyimide films using the developed ink. The conductive layer formed in air in the optimized conditions showed an electrical resistivity of 28.5 lX·cm.
关键词： Conductive inks,Laser sintering,Printed electronics,Copper,Core-shell nanoparticles,Silver
更新于2025-09-23 15:19:57
-
Femtosecond laser-induced non-thermal welding for a single Cu nanowire glucose sensor
摘要： Copper nanowires (CuNWs) are a key building block to facilitate carrier conduction across a broad range of nanodevices. For integration into nanoscale devices, manipulation and welding of these nanowires need to be overcome. Based on high energy density laser processing investigation, we report on innovative welding of single CuNWs to a silver film using a tightly focused laser beam combined with manipulation of CuNWs through the dielectrophoresis (DEP) method. Two types of lasers, femtosecond (FS) and continuous-wave (CW), were employed to analyze, improve, and control Cu-NW melting characteristics under high energy density irradiation. The FS laser welding of CuNWs resulted in a metallic joint with a low contact resistance suitable for functional electronic nanodevices. Computational simulations using the 1-D heat diffusion equation and finite difference method (FDM) were performed to gain an insight into metal–laser interactions for high performance welded contact development. Simulation studies on lasers established contrasting melting behavior of metal under laser irradiation. The device feasibility of CuNW based welded contacts was evaluated in terms of the electrical performance of a glucose sensor. It was possible to sense glucose concentration down to 10?6 M, demonstrating a path towards integration of CuNWs into wearable, flexible nanoelectronic devices.
关键词： glucose sensor,femtosecond laser,Copper nanowires,laser welding,dielectrophoresis,nanoelectronics,continuous-wave laser
更新于2025-09-23 15:19:57
-
Controlled switching of a single CuPc molecule on Cu(111) at low temperature
摘要： Low temperature measurements of the tunneling current as a function of the applied bias voltage have been performed on a dense constant-height grid above individual copper phthalocyanine molecules adsorbed on a Cu(111) surface. By appropriate tuning of the applied bias, the molecule can be reversibly switched between two configurations in which pairs of opposite maxima appear rotated by 90? in the tunneling current map. The underlying conformations are revealed by density functional calculations including van der Waals interactions: a C2v symmetric ground state and two energetically equivalent states, in which the molecule is twisted and rotated around its center by ±7?. For tip biases above 200 mV position-dependent current switching is observed, as in previous measurements of telegraph noise [Schaffert et al., Nat. Mater. 12, 223 (2013)]. In a small voltage interval around zero the measured current becomes bistable. Switching to a particular state can be initiated by sweeping the voltage past well-defined positive and negative thresholds at certain positions above the molecule or by scanning at constant current and a reduced reverse bias.
关键词： density functional calculations,van der Waals interactions,tunneling current,copper phthalocyanine,Cu(111) surface,bistable current
更新于2025-09-23 15:19:57