Synthesis and Structure of a Hydrogen-bonding Assembled Three-dimensional Supramolecular Indium(III) Compound Involving One-dimensional Helices

The title compound [In（H2ip）（pdc）（H2O）] （H3ip = 5-hydroxyisophthalic acid, H2Pdc = pyridine-2,6-dicarboxylic acid） has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 13.830（8）, b = 6.488（4）, c = 17.632（10）A^°, β = 92.510（10）°, C15H10InNO10, Mr= 479.06, V = 1580.6（15）A^°3, Z = 4, De= 2.013 g/cm^3, F（000） = 944,μ = 1.557 mm^-1, the final R = 0.0413 and wR = 0.0793 for 2950 observed reflections with I 〉 2σ（I）. The In（Ⅲ） ion is seven-coordinated in a slightly distorted penta-bipyramidal geometry. The mixed ligands connect the In（Ⅲ） ions into 21 helical chains along the [010] direction, and the hydrogen bonds assemble the chains into a three-dimensional supramolecular network.

InAsSb thick epilayers applied to long wavelength photoconductors

InAs0.052Sb0.948 epilayers with cutoff wavelengths longer than 8 μm were successfully grown on InAs substrates using melt epitaxy （ME）. Scanning electron microscopy observations show that the interface between the epilayers and substrates is flat, indicating the good quality of the epilayers, and the thickness of the epilayers is 40 μm. Photoconductors were fabricated using InAs0.052Sb0.948 thick epilayers grown by ME. Ge optical lenses were set on the photoconductors. At room temperature, the photoresponse wavelength range was 2-10μm. The peak detectivity Dλp reached 5.4 × 10^9 cm-Hz^1/2.W^-1 for the immersed detectors. The detectivity D^＊ was 9.3 × 10^8 and 1.3 × 10^8 cm.Hz^1/2.W^-1 at the wavelength of 8 and 9 μm, respectively. The good performance of the uncooled InAsSb detectors was experimentally validated.

Growth and Properties of In-Doped Semi-insulating GaAs Crystals

Semi-insulating (SI) GaAs doped with indium has been grown and characterized. The relationship between the dislocation density and dopant concentration has been discussed. Study of the uniformity of electric properties of In-doped SI-GaAs, which has been annealed at 950°C for 6h under arsenic pressure, associates with decreases of point defects and arsenic vacancies.

Study on Relationship between InGaAsP/InP LPE Wafer Morphology,Interface Property and Device Characteristics

Five kinds of InGaAsP/InP heterostructure materials grown with LPE have been measured by means of Auger electron analysis, X-ray double-crystal diffraction, selective etching and surface morphology analysis. The relation between crystal mismatch and interface property of such materials has been studied and the results could be understood in terms of the growth kinetics at the heterojunction interface. The comparison of the characteristics of the electronic and optoelectronic devices fabricated with the wafers under different interface properties has been carried out. And it also has been demonstrated that the wafer surface morphology changes with the compositional gradation in a certain relationship.

Growth and characterization of InAsSb alloys by metalorganic chemical vapour deposition

Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. The samples are studied by photoluminescence spectra, and the output is 3.17μm in wavelength. The surface of InAsSb epilayer shows that its morphological feature is dependent on buffer layer. With an InAs buffer layer used, the best surface is obtained. The InAsSb film shows to be of n-type conduction with an electron concentration of 8.52 × 10^16 cm^-3.

Advances of the Vertical Directional Solidification Technique for the Growth of High Quality InSb Bulk Crystals

Since 1994, the vertical directional solidification （VDS） technique is employed for the growths of bulk crystals-without the seed, without contact to the ampoule wall, without coating and without external pressure, which leads to the detached growth. Growth velocities ranged from 3 mm/h to 10 mm/h, and rotation rates 10-20 rpm have been used. Ingots, 10-20 mm diameter and 60-65 mm length, have been grown with the conical ampoule geometry and these ingots have shown symmetric detachment. Crystals grown under such conditions showed the relatively low dislocation density and the highest carrier mobility,/tn = 5.9 x 104 cm2＂Vl-sl than the crystal grown ever. For the detached crystals, the dislocation density is 104 cm＂2 in conical region, and reached less than 103 cm-2 in the direction of the growth, when the ingots are not in contact with the ampoule wall. Experiments for indium-antimonide （InSb） growth have shown that the 80% growth environments have detachment, 15% entrapped in conical region and 5% attached.

Preparation and characteristics of Nb-doped indium tin oxide thin films by RF magnetron sputtering

Niobium-doped indium tin oxide （ITO：Nb） thin films are fabricated on glass substrates by radio frequency （RF） magnetron sputtering at different temperatures. Structural, electrical and optical properties of the films are investigated using X-ray diffraction （XRD）, atomic force microscopy （AFM）, ultraviolet-visible （UV-VIS） spectroscopy and electrical measurements. XRD patterns show that the preferential orientation ofpolycrystalline structure changes from （400） to （222） crystal plane, and the crystallite size increases with the increase of substrate temperature. AFM analyses reveal that the film is very smooth at low temperature. The root mean square （RMS） roughness and the average roughness are 2.16 nm and 1.64 nm, respectively. The obtained lowest resistivity of the films is 1.2 × 10^4 Ω-cm, and the resistivity decreases with the increase of substrate temperature. The highest Hall mobility and carrier concentration are 16.5 cmVV.s and 1.88× 10^21 cm^-3, respectively. Band gap energy of the films depends on substrate temperature, which is varied from 3.49 eV to 3.63 eV.

An air-stable inverted photovoltaic device using ZnO as the electron selective layer and MoO_3 as the blocking layer

An air-stable photovoltaic device based on znic oxide nanoparticles （ZNP） in an inverted structure of indium tin oxide （ITO）/ZnO/poly （3-hexylthiophene） （P3HT）： [6,6]-phenyl C61-butyric acid methyl ester （PCBM）/MoO3/Ag is studied. We fm.d that the optimum thickness of the MoO3 layer is 2 nm. When the MoO3 blocking layer is introduced, the fill factor of the devices is increased from 29% to 40%, the power conversion efficiency is directly promoted from 0.35% to 1.27%.The stability under ambient conditions of this inverted structure device much is better due to the improved stability at the polymer/Ag interface. The enhancement is attributed to the high carriers mobility and suitable band gap of MoO3 layer.

Optimization and degradation of rubrene/C_(70) heterojunction solar cells

Small molecule organic solar cells （OSCs） with the structure of indium tin oxide （1TO）/molybdenum trioxide （MOO3） （5 nm）/rubrene （x nm）/fullerene （C70） （y nm）/2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline （BCP） （6 nm）/aluminum （A1） （150 nm） are fabricated. The thickness of active layer for the devices is investigated in details. The results show that the optimum thicknesses of rubrene layer and C70 layer are 30 nm and 25 nm, respectively. The degradation of the device is also investigated. The result indicates that the open-circuit voltage （Voo） does not change, while the short-circuit current density （Jsc）, fill factor （FF） and power conversion efficiency （PCE） decrease continuously with time. The degradation can be attributed to the oxygen in ambient diffusing and infiltrating into the active materials and reacting with C70 in cells, which can result in the increase of interfacial series resistance.

Hybrid silicon modulators

A number of active elements have been demonstrated using the hybrid silicon evanescent platform, including lasers, amplifiers, and detectors. In this letter, two types of hybrid silicon modulators, flflfilling the building blocks in optical communication on this platform, are presented. A hybrid silicon electroabsorp- tion modulator, suitable for high speed interconnects, with 10-dB extinction ratio at -5 V and 16-GHz modulation bandwidth is demonstrated. In addition, a hybrid silicon Mach-Zehnder modulator utilizing carrier depletion in multiple quantum wells is proved with 2 V.mm voltage-length product, 150-nm optical bandwidth, and a large signal modulation up to 10 Gb/s.

The growth and properties of an m-plane InN epilayer on LiAlO_2 (100) by metal-organic chemical vapor deposition

The m-plane InN （1 100） epilayers have been grown on a LiAlO2 （1 0 0） substrate by a two-step growth method using a met- al-organic chemical vapor deposition （MOCVD） system. The low temperature InN buffer layer （LT-InN） is introduced to overcome the drawbacks of thermal instability of LiAlO2 （LAO） and to relieve the strains due to a large thermal mismatch be- tween LAO and InN. Then the high temperature m-plane InN （1 1 00） epilayers （HT-InN） were grown. The results of X-ray diffraction （XRD） suggest that the m-plane InN （1 1 00） epilayer is a single crystal. The X-ray rocking curves （co scans） （XRC） and atomic force microscopy （AFM） indicate that the m-plane InN （1 1 00） epilayer has anisotropic crystallographic properties. The PL studies of the materials reveal a remarkable energy band gap structure around 0.70 eV at 15 K.