PSS. The fabricated SnSe NS/PEDOT:PSS composites show a maximum figure of merit (ZT) of 0.32 at a SnSe NSs loading of 20 wt %. The mixing of inorganic nanoparticles with the conducting polymer matrix forms products with extremely low thermal conductivities, which is a promising strategy for the realization of polymer based efficient thermoelectric applications.
performance can be limited due to the slow oxidation kinetics and consequent low degree formation of MOOH intermediates. [16,17] As such, the matter of 3D transition metals in OER activity may come down to their facile oxidation, referring to the necessity of novel structural design to tune the oxidation kinetics. Recently, heterogeneous catalysts-supported metals have shown notable OER activities resulting from the similarity of metal crystallite to support materials and catalytic synergy of support species support to the 3D metal. [18] The synergistic effect refers to modification of electronic structures of both support materials and anchored metals, which leads to the acceleration of oxidation kinetics of the anchored metal. [19] This infers that the introduction of conductive support for transition metals could help to readily transport electrons from the transition metal particles to support materials. Pyrochlore oxides (A 2 B 2 O 7 ) have a characteristic that electrons generated during oxygen evolution (4OH − → O 2 + 2H 2 O + 4e − ) are rapidly transferred from surface to inner layers with low-resistance pathway by oxidizing either A or B-site metal cation of pyrochlore oxide. [20][21][22][23][24][25] As such, the metallic conduction pyrochlore oxide can be a suitable support for transition metals, which provide a rationale for transitionmetal anchored pyrochlore oxide for OER. In the integrated design of transition metals and pyrochlore oxides, the pyrochlore oxide support effectively transfer the electrons generated during the oxidation of transition metal to pyrochlore oxide inner layers, reducing the barrier energy for the formation of MOOH intermediates.For the synthesis of metal-supported heterogeneous structure, in situ exsolution method is widely adopted in that metal nanoparticles are uniformly grown on support materials. [26][27][28][29][30] Recently, CoFe nanoalloys decorated on La 2 O 3 has been reported where the CoFe alloy particle is formed by the reduction of Co and Fe cations from LaCo 0.8 Fe 0.2 O 3−δ perovskite oxide. [31] The CoFe/La 2 O 3 catalyst showed notable OER potential of 1.52 V versus RHE at the current density of 10 mA cm −2 in alkaline medium, showing the transformation of CoFe nanoalloys to (Co/Fe)O(OH) intermediation. However, the OER active sites of the CoFe/La 2 O 3 only come from the CoFe nanoalloys, for the perovskite oxide (ABO 3 ) support are transformed to OER inactive metal oxide (i.e., La 2 O 3 ). The reduction of all the Co It is crucial for leaping forward renewable energy technology to develop highly active oxygen evolution reaction (OER) catalysts with fast OER kinetics, and the novel design of high-performance catalysts may come down to unveiling the origin of high catalytic behavior. Herein, a new class of heterogeneous OER electrocatalyst (metallic Co nanoparticles anchored on yttrium ruthenate pyrochlore oxide) is provided for securing fast OER kinetics. In situ X-ray absorption spectroscopy (in situ XAS) reveals that fast OER kinetics can be achieved by t...
Abstract-We investigate nonlinear carrier dynamics in a multiquantum-well semiconductor optical amplifier (SOA) in the context of ultrafast all-optical logic. A rate-equation model is presented that accounts for two-photon absorption, free-carrier absorption, self-and cross phase modulation, carrier heating, spectral, spatial hole burning, and self-and cross polarization modulation. The nonlinear refractive index dynamics is investigated theoretically and experimentally. We find nonlinear phase changes larger than radians, which recovers on a timescale in the order of 1 ps. We also investigate a nonlinear AND gate that consists of an SOA that is placed in an asymmetric Mach-Zehnder interferometer. We show that the gate can be operated using 800-fJ optical pulses with duration of 200 fs while having a contrast ratio larger than 11 dB.Index Terms-Optical logic, optical signal processing ultrafast carrier dynamics, semiconductor optical amplifier.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.