SEMICONDUCTING PROPERTIES OF In_2O_3 ANODIC FILM

The good potentiality of the In_2O_3 anodic film as a photoanodic material has been demonstrated.The anodic oxidation of In substrate in alkaline solution for obtaining In_2O_3 film has been developed and their semiconducting properties have been investigated through capacitance, photoelectrochemistry and electroreflection measurements.

Effect of Chloride on Semiconducting Properties of Passive Films Formed on Supermartensitic Stainless Steel in NaHCO_3 Solution

The effects of chloride ion on the electrochemical behavior and the semiconducting properties of the passive film on supermartensitic stainless steel in 0.5 mol/L NaHCO_3 solution were investigated using potentiodynamic polarization, the potentiostatic current transients and Mott-Schottky analysis. The results indicated that chloride ion narrowed passivation region and improved pitting susceptibility. The steady state current densities were independent of film-formed potentials, which was in good agreement with the assumption of the point defect model （PDM）. The capacitance results showed the fact that the passive films had a multilayer character. The defect density decreased with increasing passive film formation potential. The chloride ion induced changes of the acceptor densities and donor densities of the passive films.

Structure and Semiconducting Character of a Polymeric Iodoplumbate Coordination Complex

A new polymeric iodoplumbate complex [Zn（DMF）6][Pb2I6] 1 has been prepared and characterized by elemental analysis and single-crystal X-ray analysis. Its structure contains infinite iodoplumbate chains constructed by the [PbI5] subunit. EHT crystal orbital calculation and the experimental results show that this material is an unconventional semiconductor and the electrical character is associated with its structural feature.

Sub-nano Layers of Li, Be, and Al on the Si(100) Surface: Electronic Structure and Silicide Formation

Within the framework of the density functional theory and the pseudopotential method,the electronic structure calculations of the“metal-Si(100)”systems with Li,Be and Al as metal coverings of one to four monolayers(ML)thickness,were carried out.Calculations showed that band gaps of 1.02 eV,0.98 eV and 0.5 eV,respectively,appear in the densities of electronic states when the thickness of Li,Be and Al coverings is one ML.These gaps disappear with increasing thickness of the metal layers:first in the Li-Si system(for two ML),then in the Al-Si system(for three ML)and then in the Be-Si system(for four ML).This behavior of the band gap can be explained by the passivation of the substrate surface states and the peculiarities of the electronic structure of the adsorbed metals.In common the results can be interpreted as describing the possibility of the formation of a two-dimensional silicide with semiconducting properties in Li-Si(100),Be-Si(100)and Al-Si(100)systems.

Simple Preparation, Structure and Conductivity of Nickel(Ⅱ) Benzenetricarboxylate Ni_3(BTC)_2·12H_2O

Proton-conductive crystalline metal-organic framework nickel（Ⅱ） benzenetricar- boxylate Ni3（BTC）2A12H2O（MOF-Ni） was prepared by the reaction of nickel（Ⅱ） nitrate and 1,3,5- benzenetricarboxylic（BTC） acid in a mixed solvent of N,N-dimethylformamide（DMF）/C2H5OH/ H2O （1：1：1, ν/ν） at low temperature and short reaction time. It was characterized by thermo- gravimetric analyses （TG）, FT-IR and N2 adsorption-desorption. Single-crystal X-ray diffraction analysis indicated that the complex belongs to monoclinic system, space group C2 with α = 17.407（6）, b = 12.878（5）, c = 6.542（2） A, β = 112.07°, V = 1359.0（8） A^3, Dc = 1.971 g/cm3, μ = 2.166 mm^-1 and Z = 2. Linear polarization resistance （LPR） analysis showed that the complex possesses semiconducting properties.

Growth and Characterization of Indium Doped Zinc Oxide Films Sputtered from Powder Targets

Indium doped Zn O films were grown on quartz glass substrates by radio frequency magnetron sputtering from powder targets. Indium content in the targets varied from 1at% to 9at%. In doping on the structure, optical and electrical properties of Zn O thin films were studied. X-ray diffraction shows that all the films are hexagonal wurtzite with c-axis perpendicular to the substrates. There is a positive strain in the films and it increases with indium content. All the films show a high transmittance of 86% in the visible light region. Undoped Zn O thin film exhibits a high transmittance in the near infrared region. The transmittance of indium doped Zn O thin films decreases sharply in the near infrared region, and a cut-off wavelength can be found. The lowest resistivity of 4.3×10^（-4） Ω·cm and the highest carrier concentration of 1.86×10^（21） cm^（-3） can be obtained from Zn O thin films with an indium content of 5at% in the target.

Effects of W Addition on the Electrochemical Behaviour and Passive Film Properties of Fe-Based Amorphous Alloys in Acetic Acid Solution

The electrochemical behaviour and passive film properties of Fe-Cr-Mo-W-C-B-Y amorphous alloys in acetic acid solution were investigated. The potentiodynamic polarisation and Nyquist curves demonstrated that W addition signifi- cantly enhanced the corrosion resistance. Mott-Schottky plots and angle-resolved X-ray photoelectron spectra indicated that passive films with different W contents exhibited dipolar （p-n） semiconducting characteristics separated by fiat-band potentials. The outer and inner oxide layers of the passive films were modified by reducing the acceptor and donor densities. Moreover, W addition favoured the formation of a thicker and more stable passive film to inhibit the dissolution of alloy elements.

Covalent Organic Frameworks with trans-Dimensionally Vinylene-linked π-Conjugated Motifs

Vinylene-linked covalent organic frameworks(COFs) are a class of promising porous organic materials that feature fully π-conjugated structures, high crystallinity, permanent porosity, ultrahigh chemical stability, and extraordinary optoelectronic properties. Over the past 5 years, this kind of material has been witnessed rapid development either in chemical synthesis or in potential applications. In this review, we summarize the chemistry to synthesize vinylene-linked COFs, especially the synthetic strategies involving activation of aryl methyl groups for condensation reaction. We then scrutinize the state-of-the-art development in properties and functions of this kind of COFs. Our own opinions on the further development of the vinylene-linked COFs are also presented for discussion.