Erratum to: Charge transfer in graphene/polymer interfaces for CO2 detection

Nano Research - The order of the authors in the original version of this article was unfortunately incorrect on the first page and the first page of the ESM. Instead of Myungwoo Son1, Yusin Pak1,...     

Thermally controlled wavelength locker integrated in widely tunable SGDBR-LD module

A sampled-grating distributed Bragg reflector laser module having an integrated multiwavelength locker has been developed and evaluated. The uniquely designed wavelength locker made of thermally controlled etalon has provided uniform wavelength monitoring and very stable wavelength locking in the 188-ITU grid channels (37 nm) with 25-GHz spacing. Over the case temperature from -5/spl deg/C to 65/spl deg/C, the laser wavelength was locked within /spl plusmn/0.5 GHz, and the total power consumption of the module was less than 4 W.     

The design and the fabrication of monolithically integrated GaInAsP MQW laser with butt-coupled waveguide

We optimized the etching process for butt coupling to improve the reproducibility and the uniformity of the process for the integrated GaInAsP multiquantum-well laser with a butt-coupled waveguide. Three different ways of etching process were tested, which are reactive ion etching (RIE), RIE followed by a small amount (50 nm thick) of selective wet etching, and RIE followed by an adequate amount (125 nm thick) of selective wet etching. RIE followed by an adequate amount of selective wet etching showed the superior properties to the common expectation on RIE only, giving the measured coupling efficiency 96/spl plusmn/1.7% versus 34/spl plusmn/8%. The high coupling efficiency and the very small variation across a quarter of a 2-in wafer demonstrate that RIE coupled with an adequate amount of selective wet etching can also replace the conventional process for butt coupling, RIE followed by HBr-based nonselective wet etching, to fabricate high-quality integrated photonic devices.     

Fabrication of wavelength-tunable butt-coupled sampled grating DBR lasers using planar buried heterostructure

Planar buried heterostructure (PBH) was adopted to fabricate a sampled grating distributed Bragg reflector laser diode (SGDBR-LD) having a low threshold current and a stable fundamental transverse mode. The etching process for butt-coupling was optimized to improve the reproducibility and the uniformity of the butt-coupled waveguide. The maximum output power of the fabricated SGDBR-LD was 20 mW at 200-mA continuous-wave operation at 25/spl deg/C. The output power was measured 10 and 9 mW higher than those of ridged waveguide (RWG) structure and buried ridge stripe (BRS), and the threshold current was slightly higher than those of RWG and BRS. The spectra of 25 channels spaced 50 GHz within the tuning range of 44.4 nm was obtained by a precise control of SG and phase control currents. The side-mode suppression ratio of more than 35 dB was obtained in the whole tuning range. The output power variation was less than 5 dB, which is 4 dB smaller than that of RWG structure.     

Band-gap modulation in single-crystalline Si1-xGex nanowires

We report the energy band-gap modulation of single-crystalline Si1-xGex (0 相似文献   

Signatures of molecular magnetism in single-molecule transport spectroscopy

We report single-molecule-transistor measurements on devices incorporating magnetic molecules. By studying the electron-tunneling spectrum as a function of magnetic field, we are able to identify signatures of magnetic states and their associated magnetic anisotropy. A comparison of the data to simulations also suggests that sequential electron tunneling may enhance the magnetic relaxation of the magnetic molecule.     

Anomalous thickness-dependence of photocurrent explained for state-of-the-art planar nano-heterojunction organic solar cells

Due to their simple geometry and design, planar heterojunction (PHJ) solar cells have advantages both as potential photovoltaics with more efficient charge extraction than their bulk heterojunction (BHJ) counterparts, and as idealized interfaces to study basic device operation. The main reason for creating BHJs was the limited exciton diffusion length in the active materials of the PHJ: if an exciton is generated at a distance greater than its diffusion length from the hetero-interface of the PHJ, it would be very unlikely to be able to contribute to the photocurrent. Based on this argument one expects a maximum in the photocurrent of PHJs for a thickness of the active layer equal to the exciton diffusion length (~10 nm). However, in two recently developed PHJs that have appeared in the literature, a maximum photocurrent is observed for 60-65 nm of poly(3-hexylthiophene) (P3HT). In this work, we explore this anomaly by combining both an optical T-matrix and a kinetic Monte Carlo simulation that tracks the exciton behavior in the PHJs. The two systems considered are a P3HT/single walled carbon nanotube (SWNT) device, and a P3HT/phenyl-C61-butyric acid methyl ester (PCBM) device. The model demonstrates how a bulk exciton sink can explain the shifted maximum in the P3HT/SWNT case, whereas in the P3HT/PCBM case the maximum is mainly determined by PCBM molecules interdiffusing in the P3HT upon annealing. Based upon the results of this model it will be possible to more intelligently design nanostructured photovoltaics and optimize them toward higher efficiencies.     

Three-dimensional shape reconstruction from images by shape-from-silhouette technique and iterative triangulation

We propose an image-based three-dimensional shape determination system. The shape, and thus the three-dimensional coordinate information of the 3-D object, is determined solely from captured images of the 3-D object from a prescribed set of viewpoints. The approach is based on the shape-from-silhouette (SFS) technique, and the efficacy of the SFS method is tested using a sample data set. The extracted three-dimensional shape is modeled with polygons generated by a new iterative triangulation algorithm, and the polygon model can be exported to commercial software. The proposed system may be used to visualize the 3-D object efficiently, or to quickly generate initial CAD data for reverse engineering purposes, including three dimensional design applications such as 3-D animation and 3-D games.     

A Test of Major Assumptions About Behavior Change: A Comprehensive Look at the Effects of Passive and Active HIV-Prevention Interventions Since the Beginning of the Epidemic.

This meta-analysis tested the major theoretical assumptions about behavior change by examining the outcomes and mediating mechanisms of different preventive strategies in a sample of 354 HIV-prevention interventions and 99 control groups, spanning the past 17 years. There were 2 main conclusions from this extensive review. First, the most effective interventions were those that contained attitudinal arguments, educational information, behavioral skills arguments, and behavioral skills training, whereas the least effective ones were those that attempted to induce fear of HIV. Second, the impact of the interventions and the different strategies behind them was contingent on the gender, age, ethnicity, risk group, and past condom use of the target audience in ways that illuminate the direction of future preventive efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)