ABSTRACT
Facile strategies in flexible transparent conductive electrode materials that can sustain their electrical conductivities under 1 mm-scale radius of curvature are required for wider applications such as foldable devices. We propose a rational design as well as a fabrication process for a silver nanowire-based transparent conductive electrode with low sheet resistance and high transmittance even after prolonged cyclic bending. The electrode is fabricated on a poly(ethylene terephthalate) film through the hybridization of silver nanowires with silver nanoparticles-anchored RuO2 nanosheets. This hybridization significantly improves the performance of the silver nanowire network under severe bending strain and creates an electrically percolative structure between silver nanowires and RuO2 nanosheets in the presence of anchored silver nanoparticles on the surface of RuO2 nanosheets. The resistance change of this hybrid transparent conductive electrode is 8.8% after 200,000 bending cycles at a curvature radius of 1 mm, making it feasible for use in foldable devices.
ABSTRACT
The enhancement in electrical transport properties of exfoliated individual RuO2 NSs was systemically investigated for their application in flexible electronics and optoelectronics. Decoration of Ag NPs on the surface of the RuO2 NSs provides donor electrons and dramatically increases the electrical conductivity of the monolayer RuO2 NSs by up to 3700%. The n-type doping behavior was confirmed via Hall measurement analysis of the doped RuO2 NSs. The layer number- and temperature-dependence of the conductivity were also investigated. Moreover, carrier concentration and mobility were obtained from Hall measurements, indicating that the undoped RuO2 NSs had ambipolar transport and semi-metallic characteristics. Moreover, the Ag-doped RuO2 NS multilayer films on polycarbonate substrates were demonstrated by the Langmuir-Blodgett assembly methods, showing one-third reduction in the sheet resistance and extraordinarily high bending stability that the change in the resistance was less than 1% over 50 000 cycles.
ABSTRACT
The emergence of metallic conduction in layered dichalcogenide semiconductor materials by chemical doping is one of key issues for two-dimensional (2D) materials engineering. At present, doping methods for layered dichalcogenide materials have been limited to an ion intercalation between layer units or electrostatic carrier doping by electrical bias owing to the absence of appropriate substitutional dopant for increasing the carrier concentration. Here, we report the occurrence of metallic conduction in the layered dichalcogenide of SnSe2 by the direct Se-site doping with Cl as a shallow electron donor. The total carrier concentration up to ~10(20) cm(-3) is achieved by Cl substitutional doping, resulting in the improved conductivity value of ~170 S · cm(-1) from ~1.7 S · cm(-1) for non-doped SnSe2. When the carrier concentration exceeds ~10(19) cm(-3), the conduction mechanism is changed from hopping to degenerate conduction, exhibiting metal-insulator transition behavior. Detailed band structure calculation reveals that the hybridized s-p orbital from Sn 5s and Se 4p states is responsible for the degenerate metallic conduction in electron-doped SnSe2.
ABSTRACT
Three-dimensional (3D) self-assembled hierarchical bismuth oxide architectures were prepared via a solution precipitation synthesis at 85 degrees C in 45 min with the aid of polyethylene glycol-8000 (PEG-8000) as a capping agent. The morphology and crystalline phase evolution was studied versus reaction time and capping agent concentration and interpreted in terms of growth mechanisms. At higher capping agent concentrations, the as-grown 3D hierarchical flowerlike bismuth oxide was crystalline cubic gamma-phase that was previously formed only at temperature > or =640 degrees C. The morphology and crystal structure of these 3D cubic gamma-phase bismuth oxide flowers were not changed with calcining up to 600 degrees C. Photoluminescence was attributed to emission from the Bi(3+) ion by a (3)P(0),(1) --> (1)S(0) transition and from defects. The gamma-phase flowerlike bismuth oxide shows better ion conductivity than that of rodlike bismuth oxide formed without the capping agent. The flowerlike morphology was attributed to modification of the nucleation and growth kinetics by the capping agent.
