The current status of theoretical and experimental studies on the spatial implanted ion distributions and associated phenomena is generally surveyed. At first, fundamental factors determining the ion distributions such as the nuclear and electronic stopping powers are briefly described. And, according to the analysis using the Legendre polynomials, the basic theory concerning with the ion distributions is derived. Second, the theoretical results are compared with the experimental ones to show reasonable good agreement between both results. The deviation from the theoretically predicted distributions due to the channelling effect and the sputtering effect of the substrate surfaces is also reviewed. At last, some problems to which the above theory can not be applied, such as the ion distributions in multi-layer substrates, damage distributions and knock-on effects, are discussed.
A general survey of the solar energy and its conversion to other types of energy, has been made from the view point of applied physics. Physical processes of the energy conversion from the sun beam are classified, and material sciences for the photo-voltaic, photo-thermal and photo-chemical power generation systems are also discussed. Device Physics for the low cost, high efficiency energy conversion elements are reviewed from the recent investigations in the fields. It has been demonstrated that there are some possibilities remained to improve the solar cell performances with reducing the cost by combining several new principles reviewed, apart from the progressing practical approaches such as scale, up of production process with the automatization and standardizations etc.
Stacking faults in thermally oxidized silicon were examined by etching. The shape of stacking faults and their density distribution by depth became visible with additional 1HF-4HNO3-1 acetic acid mixture etching after Sirtl etching. Various shaped Frank sessile dislocations surrounding extrinsic stacking faults were observed. Generally, Frank loops were semicircular, though irregular, circular and hexagonal shaped loops and double layer stacking faults were also detected. It was proved that stacking faults were generated not only at the surface but into the bulk silicon several micrometers deep from the surface. Stacking faults had relatively uniform size in “singly” oxidized silicon, however, their size varied in “multiply” oxidized silicon. The ratio of depth to length were about 0.3 and 0.15-1 for singly and triply oxidized (100) wafers, respectively.
The photocurrent obtained through a circular aperture when two laser beams are super-posed is calculated by a square law detector. The photocurrent obtained through a circular aperture when two laser beams are super-posed is calculated by a square law detector.
In this paper, the electrical and optical properties of transparent conducting films prepared by a vacuum evaporation of tin accetate (Sn(CH3COO)2) and subsequent heat treatment were investigated. Such transparent conducting films were formed on the substrate of heated Pyrex glass plates by heating the Sn(CH3COO)2 evaporated film in air at a temperature range of 500_??_600°C. These properties are greatly influenced by the conditions of evaporation and the heat treatment proccess, especially, the wafer temperature (Ts) in vacuum evaporation, subsequent baking temperature (Tb) and its baking time (tb). The minimum sheet resistivity and maximum transmission of the films were given at Ts =150°C, Tb=600°C and tb_??_0.5 hour. On investigating the X-ray diffraction patterns, it has been obtained that the films consisting of SnO2 belong to a tetragonal system, and that the lattice constants a and c of the primitive cell are a=4.72Å and c=3.21Å respectively. The electrical and optical properties of the films are similar to the authentic sample in the literature with SnCl4 as a starting material.
As2S3Agx glasses with varying Ag content were prepared. It has been found that the glasses with x≥0.402 (15 wt % Ag) show reversible memory switching and remarkable ionic conduction by silver ions at room temperature. The formation of conductive filament in this memory switching was not identified by microscopic observation. However, a dendritic high conducting path, which never again returns to have a high resistance, is formed by passing a larger current through the sample in the memory state. In a low dc field, silver ions migrate to the negative electrode and are deposited on its surface as metallic silver, whereas a depletion layer of silver ions is formed near the positive one. The activation energy obtained from temperature dependence of resistivity changes sharply in the composition range between x=0.311 and 0.402.
A photoelectron counting system was set up for the statistical studies of fluctuating light intensities of a limited duration, where a maximal exploitation of the data on time intervals between neighbouring pulses and their sequence in a photoelectron pulse train is required in order to maximize the statistical accuracy of a desired information on the light. The idea that has been adopted here is to store the data and to use them repeatedly until complete information is extracted. The performance is demonstrated for He-Ne laser light itself and He-Ne laser light scat-tered from a suspension of polystylene spheres in water.
A novel method for narrowing the spectrum of a dye laser is realized by using a vapor prism. In a vapor cell which has a heated boat and a cooler top, the vapor will be found to be very dense along the boat and highly attenuated along the top in presence of foreign gas. Thus a sodium vapor cell behaves as the optical equivalent of a prism with a variation of refractive index along the vertical direction. This vapor prism has a large dispersive power in the anomalous dispersion region near the resonance line. The dispersion curve of the prism using sodium vapor was measured and the dispersive power at the wavelength of 5891. 5Å is equivalent to that of a diffraction grating with 2×104 grooves per mm. With the vapor prism inside a laser cavity, a laser oscillation spectrum of less than 0.1Å was obtained at sodium temperature of 320°C.