Growth of Ga_xIn_(1-x)Sb Alloys by MOCVD Solid Composition Surface Morphology and Electrical Properties

a.In-Sb alloys were grown on GaSb substrates by MOCVD at atmospheric pressure. TMGa, TMInand TMSb were used as reactants. Alloy solid competition , surface morphologies and electrical properties wereinvestigated. It was found that the growth temperature was a key parameter for optimized surface morphologyand crystalline quality of the Ga_zIn_1-Sb epilayers. The influence of growth temperature on the Ga solidcomposition was previously explained. The Ga solid composition was proportional to the Ga vapor compositionand vapor Ⅲ/V ratio, respectively . The Ga distribution as efficient was found to be 1. 22 under the optimizedgrowth parameters and decreased with decreasing growth temperature. The results of Hall measurements forGa.InSb alloys at room temperature show a P-type background doping. The hole mobility of the best samplewas 377 cm￣2/V s with a hole concentration of 7. 6 x 10￣16 cm￣(-3).

Electrical Properties and Applications of (ZrO_2)_(0.92)(Y_2O_3)_(0.08) Electrolyte Thin Wall Tubes Prepared by Improved Slip Casting Method

mole fraction) yttria-stabilized zirconia electrolyte thin wall tubes were p repared by i mproved slip casting method. The length and wall thickness of the tubes are 266 mm and 0.4～0.9 mm, respectively and the relative density is 96.7%. The microstr ucture and electrical properties of samples sintered at different temperatures w ere studied using SEM and ac impedance spectroscopy. The effect of sintered dens ity, grain and grain boundary on the electrical properties of the samples was analyzed. The research results show that the density of the samples increase s gradually with increasing sintering temperatures. The microstructure of sample s strongly influences its electrical properties, and the electrical properti es of samples enhance with the increase of sintered density. The ionic conductiv ity of grain and grain boundary is increased as the sintering temperature incre ases. Better sinterability of the samples was obtained at the sintering temperat ure of 1650 ℃. The maximum open circuit voltage and short circuit current for s ingle cell is 0.946 V and 1.84 A, respectively. The maximum output power of sing le cell is 0.46 W at the temperature of 850 ℃.

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Flexible Oxide-Based Thin-Film Transistors on Plastic Substrates for Logic Applications

Phosphorus doped（P-doped） nanogranular SiO2 films have been deposited by plasma-enhanced chemical vapor deposition. A high proton conductivity of;.2x10-4S/cm and a large electric double layer（EDL） capacitance of;.2μF/cm2 have been obtained. Flexible coplanar-gate EDL thin film transistors（TFTs） gated by P-doped nanogranular SiO2 films are self-assembled on plastic substrates at room temperature. Due to the big EDL capacitance,such TFTs show ultra-low voltage operation of 1 V,a large field-effect mobility of 18.9 cm2/Vs,a small subthreshold swing of 85 m V/decade and a high current on/off ratio of 107. Furthermore,the EDL TFT could work in dual coplanar gate mode. AND logic operation is realized. Our results demonstrate that such TFTs gated by P-doped nanogranular SiO2 films have potential applications in low-power flexible electronics.

Physical mechanism of field modulation effects in ion implanted edge termination of vertical GaN Schottky barrier diodes

In this study,the physical properties of F ion-implanted GaN were thoroughly studied,and the related electric-field modulation mechanisms in ion-implanted edge termination were revealed.Transmission electron microscopy re.sults indicate that the ion-implanted region maintains a single-crystal structure even with the implantation of high-energy F ions,indicating that the high resistivity of the edge termination region is not induced by amorphization.Alternately,ion implantation-induced deep levels could compensate the electrons and lead to a highly resistive layer In addition to the bulk ffect,the direct bombardment of high-energy F ions resulted in a rough and nitrogen-deficient surface,which was confirmed via atomic force microscopy(AFM)and X-ray photoelectron spectroscopy,The implanted surface with a large density of nitrogen vacancies can accommodate electrons,and it is more conductive than the bulk in the implanted region,which is validated via spreading resistance profiling and conductive AFM measurements.Under reverse bias,the implanted surface can spread the potential in the lateral direction,whereas the acceptor traps capture electrons acting as space charges,shifting the peak electric field into the bulk region in the vertical direction.As a result,the Schottky barrier diode terminated with high-energy F ion-implanted regions exhibits a breakdown voltage of over 1.2 kv.

ANALYTIC SOLUTION OF STATIC ELECTRIC FIELD IN NEAR-EARTH SPACE

A set of magnetic-line-coordinate systems is used to much simplify the conservation equation of space electric currents in an anisotropic electric conductivity medium. Analytic expressions of eletric potential pattern in near-earth space are then obtained under a rather general condition. Discussions of simplified expressions of the electric potential pattern in various special regions, i.e. lower altitudes, equatorial region, polar region and higher altitudes, are given. It is shown that they can all be expressed as the solutions of the Riccatitype differential equations or even simpler solutions.

Investigation on the Cs 6S_(1/2)to 7D elec trie quadrupole tr ansition via monochromatic two-photon process at 767 nm

We experimentally demonstrate the cesium electric quadrupole t ransition from the 6S_(1/2)ground st ate to the 7D_(3/2,5/2)excited state t hrough a virtu al level by using a single laser at 767 nm.The excited state energy level population is characterized by varying the laser power,the temperature of the vapor,and the polarization combinations of the laser beams.The optimized experimentai parameters are obtained for a high resolution transition interval identification.The magnetic dipole coupling constant A and elec trie quadrupole coupling constant B for the 7D_(3/2,5/2)states are precisely determined by using the hyperfine levels intervals.The results,A=7.39(0.06)MHz,B=-0.19(0.18)MHz for the 7D_(3/2)state,and A=-1.79(0.05)MHz,B=1.05(0.29)MHz for the 7D_(5/2)state,are in good agreement with the previous reported results.This work is beneficial for the determination of atomic structure information and parity non-conser vat ion,which paves the way for the field of precision measurements and atomic physics.

非易失性存储器的发展及应用

半导体存储器计算机硬件中必不可少的一项设备就是存储器,信息化的处理离不开对信息的保存,因此,随着计算机的诞生和发展,先后出现了各式各样的存储器,而半导体存储器就是其中之一。