Aseries of assembled Pt II complexes comprising Nheterocyclic carbene and cyanide ligands was constructed using different substituent groups,[ Pt(CN) 2 (R-impy)] (R-impyH + = 1-alkyl-3-(2-pyridyl)-1H-imidazolium, R = Me (Pt-Me), Et (Pt-Et), i Pr (Pt-i Pr), and t Bu (Pt-t Bu)). All the complexes exhibited highly efficient photoluminescence with an emission quantum yield of 0.51-0.81 in the solid state at room temperature,originating from the triplet metal-metal-toligand charge transfer (3 MMLCT) state.Their emission colors cover the entire visible region from red for Pt-Me to blue for Pt-t Bu.I mportantly, Pt-t Bu is the first example that exhibits blue 3 MMLCT emission. The 3 MMLCT emission was proved and characterized based on the temperature dependences of the crystal structures and emission properties.T he wide-range color tuning of luminescence using the 3 MMLCT emission presents an ew strategy of superfine control of the emission color.

Articles you may be interested inThe growth-temperature dependence of the optical spin-injection dynamics in self-assembled quantum dots (QDs) of In 0.5 Ga 0.5 As was studied by increasing the sheet density of the dots from 2 Â 10 10 to 7 Â 10 10 cm À2 and reducing their size through a decrease in growth temperature from 500 to 470 C. The circularly polarized transient photoluminescence (PL) of the resulting QD ensembles was analyzed after optical excitation of spin-polarized carriers in GaAs barriers by using rate equations that take into account spin-injection dynamics such as spin-injection time, spin relaxation during injection, spin-dependent state-filling, and subsequent spin relaxation. The excitation-power dependence of the transient circular polarization of PL in the QDs, which is sensitive to the state-filling effect, was also examined. It was found that a systematic increase occurs in the degree of circular polarization of PL with decreasing growth temperature, which reflects the transient polarization of exciton spin after spin injection. This is attributed to strong suppression of the filling effect for the majority-spin states as the dot-density of the QDs increases.

Abstract. Transportation network conditions vary significantly during the course of a day. In many urban areas, public transit and (private) automobiles constitute the actual forms of transportation that use such networks. Public transportation by rail is more reliable than by automobiles or buses; therefore, ordinary static and deterministic traffic assignment models with combined mode and route choices may not be suitable to assess a transportation network that includes public railways. Moreover, within-day dynamics and reliability need to be incorporated in such a model. In this paper, we use a semi-dynamic traffic assignment model that considers within-day dynamics by improving the static traffic assignment model. In addition, stochastic travel times are incorporated into the model. Thus, we propose a semi-dynamic traffic assignment model with mode choice between public transit and automobiles, route choice with stochastic travel times, and an accompanying computing algorithm. This model enables us to assess within-day dynamics of transportation networks and travel time reliability of public railways.

We have demonstrated the fabrication of homogeneously distributed In 0.3 Ga 0.7 N/GaN quantum nanodisks (QNDs) with a high density and average diameter of 10 nm or less in 30-nm-high nanopillars. The scalable top-down nanofabrication process used biotemplates that were spincoated on an In 0.3 Ga 0.7 N/GaN single quantum well (SQW) followed by low-damage dry etching on ferritins with 7 nm diameter iron cores. The photoluminescence measurements at 70 K showed a blue shift of quantum energy of 420 meV from the In 0.3 Ga 0.7 N/GaN SQW to the QND. The internal quantum efficiency of the In 0.3 Ga 0.7 N/GaN QND was 100 times that of the SQW. A significant reduction in the quantum-confined Stark effect in the QND structure was observed, which concurred with the numerical simulation using a 3D Schrodinger equation. These results pave the way for the fabrication of large-scale III− N quantum devices using nanoprocessing, which is vital for optoelectronic communication devices.

An exclusive advantage of semiconductor spintronics is its potential for optospintronics that will allow integration of spin-based information processing/storage with photon-based information transfer/communications. Unfortunately, progresses have so far been severely hampered by the failure to generate nearly fully spin-polarized charge carriers in semiconductors at room temperature. Here, we demonstrate successful generation of conduction electron spin polarization exceeding 90% at room temperature without a magnetic field in a non-magnetic all-semiconductor nanostructure, which remains high even up to 110°C. This is accomplished by remote spin filtering of InAs quantum-dot electrons via an adjacent tunneling-coupled GaNAs spin filter. We further show that the quantum-dot electron spin can be remotely manipulated by spin control in the adjacent spin filter, paving the way for remote spin encoding and writing of quantum memory as well as for remote spin control of spin-photon interfaces. This work demonstrates the feasibility to implement opto-spintronic functionality in common semiconductor nanostructures.