We present a comprehensive comparative study of properties BN and C nanotubes using full potential linear combination atomic orbitals approach, as well planewave pseudopotential method. This paper covers our results on the structural, mechanical, vibrational, electronic properties, examining in detail effects intertube coupling. Structural aspects mechanical are discussed compared nanotubes, to experiment. Upshifts values radial breathing modes, due coupling, found be small systematic, about...

Crystalline carbon nitride powder has been successfully prepared via the liquid–solid reaction between anhydrous C3N3Cl3 and Li3N in benzene at 355 °C 5–6 MPa for 12 h. X-Ray diffraction (XRD) indicated that major part of our brown sample was composed mainly α-C3N4 β-C3N4 with lattice parameters a = 6.49 Å, c 4.70 Å 6.43 2.43 β-C3N4. photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FTIR), electron energy-loss (EELS) energy loss near edge structure (ELNES) strongly...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Jin-Hua Hu, Yong-Qing Huang, Xiao-Feng Duan, Qi Wang, Xia Zhang, Jun Xiao-Min Ren; Enhanced absorption of graphene strips with a multilayer subwavelength grating structure. Appl. Phys. Lett. 1 December 2014; 105 (22): 221113. https://doi.org/10.1063/1.4903491 Download citation file: Ris (Zotero) Reference...

In a series of poly[di(alkyl) vinylterephthalates] (PDAVTs) synthesized via radical polymerization, fine-tuning the size and shape side groups manipulated supramolecular self-assembly led to control over formations between amorphous 2D ordered hexagonal phases. To introduce long-range structure, ester at 2- 5-positions phenyl rings laterally attached backbones had be in range propyl/isopropyl hexyl. The relatively extended observed these polymers were attributed steric effects from groups....

Pt /( Ba 0.7 Sr 0.3 ) TiO 3 (BST)/YBa2Cu3O7−x capacitors were prepared and investigated for the dead-layer (DL) thickness (td) DL dielectric constant (εd). Based on series capacitor model, td/εd ratio of 0.066 nm bulk BST ferroelectric-layer 1370 obtained through measurements capacitance–voltage characteristics. The td×εd value 120 was current–voltage Combining these data, are respectively estimated to be 2.8 42.6.

A high-speed and high-power modified uni-traveling-carrier photodiode (MUTC-PD) is optimized fabricated. The optimization method takes carrier transport as the core considers hole time limited bandwidth of MUTC-PD for first time. Taking into account impact electron RC constant on device performance, simulated In structure epitaxy, it proposed to use graded doping fit Gaussian reduce epitaxial growth error. measured reaches 34 GHz RF output power 17.1 dBm with mesa diameter <inline-formula...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTheoretical Investigation of Competing Mechanisms in the Thermal Unimolecular Decomposition Acetic Acid and Hydration Reaction KeteneXiaofeng Duan Michael PageCite this: J. Am. Chem. Soc. 1995, 117, 18, 5114–5119Publication Date (Print):May 1, 1995Publication History Published online1 May 2002Published inissue 1 1995https://pubs.acs.org/doi/10.1021/ja00123a013https://doi.org/10.1021/ja00123a013research-articleACS PublicationsRequest reuse...

We propose a planar dielectric reflector with focusing ability using concentric circular subwavelength gratings (CC-SWGs). The two-dimensional of CC-SWGs is investigated by the rigorous coupled-wave analysis (RCWA) and finite element method (FEM). By designing pattern grating surface, high numerical aperture (NA) reflectivity constructed. A CC-SWG diameter 32.6μm focal length 6μm investigated, which exhibits at normal incidence radially polarized plane wave. At reflection plane,...

An 1500 nm thick collector layer is adopted in the uni-travelling-carrier photodiode (UTC-PD) to reduce PD's capacitance, while diameter set be 20 μm for better saturation performance and optical coupling characteristic of a signal from single mode fiber. By optimizing biasing voltage input light intensity, electric field intensity would controlled make photo-generated electron UTC-PD transiting at around its peak drift velocity same time obtaining it minimum capacitance. Together with...

The nuclear-electronic orbital (NEO) method was modified and extended to positron systems for studying mixed positronic-electronic wavefunctions, replacing the mass of proton with positron. Within NEO framework, NEO-HF (Hartree-Fock) provides energy corresponding single-configuration wavefunction, minimized respect molecular orbitals expressed as linear combinations Gaussian basis functions. electron-electron electron-positron correlation can be treated in framework second-order perturbation...

A grating-integrated silicon-on-insulator (SOI)-based photodetector for use in the long wavelength was fabricated and characterized. An InGaAs/InP p-i-n structure heterogeneously integrated on an SOI-based concentric circular subwavelength grating (CC-SWG) by means of a low-temperature bonding process with benzocyclobutene as agent. The light absorption device is enhanced due to high-index-contrast CC-SWGs broadband reflector. These features lead increase quantum efficiency, whole S, C, L...

A reflection-enhanced dual-absorption InP-PIN/GaAs-DBR photodetector was fabricated and characterized. The is monolithically integrated using a heteroepitaxy growth of an InGaAs/InP "PINIP" structure on the GaAs/AlGaAs Bragg reflectors. These features lead to increase in quantum efficiency over wide wavelength range while maintaining high speed. measured increased by 48.8% comparison with that without 64% at 1522 nm 3 dB bandwidth 26 GHz reverse bias V were simultaneously obtained device.

An InGaAs/AlGaAs quantum-well laser structure was grown on a silicon substrate by adopting three-step thin (1.8 μm) and simple buffer layer. The whole metalorganic chemical vapor deposition. material quality characterized transmission electron microscopy, photoluminescence spectra, electrochemical capacitance-voltage profiler. It shows that the threading dislocation density interface roughness are effectively reduced, active region's optical properties comparable to GaAs substrate. Broad...

By sorting through hundreds of globally stable Si12C12 isomers using a potential surface search and simulated annealing, we have identified low-energy structures. Unlike knit together by Si-C bonds, the lowest energy segregated carbon silicon regions that maximize stronger C-C bonding. Positing charge separation between would produce interesting optical absorption in these cluster molecules, used time-dependent density functional theory to compare calculated properties four representing...

A novel grating-integrated mushroom-mesa photodetector is demonstrated, which uses an undercut structure and a grating focusing reflector to increase bandwidth efficiency simultaneously. The p-i-n heterogeneously integrated on non-periodic concentric circular subwavelength by wafer bonding process. High speed can be obtained using for reducing its RC time constant. Meanwhile, high quantum ability. external measured device of 30 μm in diameter 45.28% at wavelength 1.55 μm, enhanced 21.4%...

In this Letter, a novel "stepped particle swarm optimization" (SPSO) based on field intensity adjustment is proposed. After that, we used algorithm to design sub-wavelength converging grating that could be integrated with the detector back. Firstly, advantages of reverse in process two-dimensional or multi-element pattern were summarized by comparing theory forward and design. Then, common "particle (PSO) our proposal compared process; found strength at focal point obtained improved was...

Photodiode equivalent circuit models often involve numerous parameters, making the parameter extraction process complex. Therefore, this work presents a hybrid genetic algorithm (HGA) to extract photodiode parameters. Firstly, we deduce calculation formula of scattering parameters model. Then, address limitations standard (SGA) that its slow convergence and extended search times, incorporate elite strategy acceleration operator, enhancing local ability HGA. We compare performance HGA with...