We present ALMA [CII] line and far-infrared (FIR) continuum observations of seven z > 6 low-luminosity quasars (M1450 > −25 mag) discovered by our on-going Subaru Hyper Suprime-Cam survey. The [CII] line was detected in all targets with luminosities of ∼(2−10) × 108 L⊙, about one order of magnitude smaller than optically luminous quasars. Also found was a wide scatter of FIR continuum luminosity, ranging from LFIR < 1011L⊙ to ∼2 × 1012L⊙. With the [CII]-based dynamical mass, we suggest that a significant fraction of low-luminosity quasars are located on or even below the local Magorrian relation, particularly at the massive end of the galaxy mass distribution. This is a clear contrast to the previous finding that luminous quasars tend to have overmassive black holes relative to the relation. Our result is expected to show a less-biased nature of the early co-evolution of black holes and their host galaxies.

We report an investigation of the properties of dwarf galaxies (Mr < -15) inside 26 clusters at z = 0.15 – 0.25, using the X-ray data from the Chandra archive, and optical images taken with Subaru Suprime-Cam. Our results include: 1. Investigation of the dwarf galaxy density distribution is sensitive to the background galaxies and the choice of colour selection of galaxies. 2. Cluster-centric dwarf-to-giant ratio is highly sensitive to the level of subtracted background galaxies. 3. A certain fraction of faint galaxies always remain undetected by the detection algorithm near the center of clusters, even after carefully treating the halo or extra diffuse light created by bright galaxies. The number of ‘undetected’ faint galaxies varies significantly from cluster to cluster, and even from pointing to pointing. 4. Dwarf galaxies extend up to 2 Mpc from the center in most clusters. Meanwhile, the distribution of blue dwarf galaxies extends more to the outside. 5. For a given colour, the spatial distributions of dwarf galaxies and giant galaxies become similar. Namely, the most of the radial distribution comes from the colour, rather than the size, of galaxies. 6. Relative to the NFW profile, all of the galaxy populations are showing a deficit near the cluster core (r < 0.3 Mpc). 7. The dwarf-to-giant ratio shows no variation against cluster measures such as the richness and X-ray luminosity, as well as various cluster X-ray characteristics related to possible dynamical status of clusters.

Merging, resulting from galaxy interaction and collision, is one essential scenario to interpret the distinct evolutionary stages of galaxy formation. However AGNs are believed to play an essential role towards the final stages of this scenario, in particular to clear the galaxy from a large excess of dust. Selecting galaxies with both 70μm and X-ray detection will help to understand the relation between star formation and AGN. We are taking advantage of the extensive multi-wavelength coverage of the Cosmic Evolution Survey (COSMOS) field to dissect the AGN influence on infrared luminous objects. We demonstrate that enhanced star formation is more probably responsible for additional obscuration of the central AGN than the dust torus, in agreement with current galaxy formation theory. Furthermore, we demonstrate that the presence of an AGN does not increase the galaxy dust temperature significantly.

A novel synthesis route to organic-capped and colloidal ZnO quantum dots (QDs) has been developed. Specifically, zinc-di-butoxide was hydrolyzed with very dilute water (100˜600 mass ppm) dissolved in hydrophilic benzylamine and polymerized to ZnO by dehydration condensation. After formation of ZnO QDs with 2˜3 nm in diameter, growth of the QDs and exchange the surface capping ligand from hydroxyl groups and/or benzylamine to oleylamine were developed by heating the colloidal solution with oleylamine. The size of the ZnO QDs finally obtained was in the range 3˜5 nm in diameter. The QDs show high dispersibility in various organic solvents. Clear UV emission due to exciton recombination was observed; and its energy was varied according to the quantum size effect from 3.39 to 3.54 eV. By using lithium-free zinc-di-butoxide as a starting material, the defect-related VIS emission was successfully decreased and the UV emission becomes dominant. The influence of water concentration in benzylamine and oleylamine on UV emission intensity was also investigated.

The impact of the conduction band offset (CBO) between window/Cu(In,Ga)Se2 (CIGS) layers on the light soaking (LS) effect in CIGS solar cells has been studied with continuous CBO control using a (Zn,Mg)O (ZMO) window layer. Two types of CIGS solar cells with different window/buffer/absorber layers configurations were fabricated, i.e., ZMO/CIGS (without buffer layer) and ZMO/CdS/CIGS structures. The CBO values between ZMO and CIGS layers were controlled to -0.15~0.25 eV. Plus and minus signs of CBO indicate the conduction band minimums of ZMO above and below that of CIGS, respectively. Current-voltage (J-V) characteristics of the solar cells with different LS durations revealed that a positive CBO value higher than 0.16 eV induces J-V curve distortion, i.e., LS effect, and all the J-V characteristics stabilized in 30 min. The degrees of the LS effect were dominated by the CBO value between ZMO and CIGS layers in the both structure regardless of the existence of CdS buffer layers. These results indicate that the LS effect is dominated by the highest barrier for photo-generated electrons in the conduction band diagram, i.e., the CBO between ZMO and CIGS layers, and quantitatively the LS effect emerges the CBO value higher than 0.16 eV.

One of impotent materials issues of Ti-Cr-V based hydrogen storage alloys is to improve cyclic degradation of storage capacity, which has been assumed to be the effect of internal stress. We focused on the sub-micron structure of this material, which can be accumulated during cyclic use. We used 24Ti-36Cr-40V alloy for the specimens, after FZ melting. Powered samples were fabricated by mechanical grinding under Ar environment. Vacuum annealing was carried out for reducing residual stress and lattice defects. PCT properties were tested at 293 K under 4.5 MPa. XRD and TEM were carried out for important samples. In the first cycle, the annealing resulted in the increasing of storage capacity, but in the second cycle the improving was disappeared. Comparing microstructures with and without annealing, complex dislocation structures were observed after cyclic hydrogenation. It is notable that dislocation free structure was some time observed in the fine grains of less than 0.1 micron, which suggests the possibility of fine structure without defect accumulation.

Three real-time composition monitoring methods in physical vapor deposition process of CIGS thin films were proposed. One is the detection of near infrared (NIR) transmittance through the CIGS films from the IR source such as a heater back side of the substrate. One is the detection of NIR reflectance of the incident light from the films. The other is the measurement of the substrate temperature during the preparation of the CIGS films. These methods utilize the difference of the carrier density between Cu-rich (∼ 1020/cm3) and (In+Ga)-rich ( > 1016/cm3) films. The NIR transmittance through and reflectance from the Cu-rich film decrease due to high free carrier absorption. The temperature of the Cu-rich films was lower than that of the (In+Ga)-rich ones under the constant heating power because the Cu-rich films have larger radiation in proportion to absorption. Therefore, the change of Cu/(In+Ga) ratios at stoichiometry can be monitored by the variation of the NIR transmittance, NIR reflectance or the film temperature in real time. These composition monitoring methods are very useful and easily applied to the physical vapor deposition process of the CIGS films for photovoltaic application. The solar cell with active area of about 0.5 cm2, fabricated by obtaining the CIGS film using the latter monitoring method, showed an efficiency of 17.0%.

Precise control of critical dimension(CD) loss (defined as the length of the top of contact hole minus the bottom of resist in this paper) and etched profile of contact holes is a key technology in the fabrication of Ultra Large Scaled Integrated Circuit(ULSI). In case of fine contact hole etching, small CD loss and vertical profile is essential. We have found out that N2 addition to Ar/CHF3/CF4 sharpens etched profile with CD loss kept small. And N2 addition also increases etch rate without a heavy deterioration of selectivity of SiO2 versus heavily doped n-type poly cry stall ine Si(n+ poly Si). Mechanisms of changes in etching characteristics have been investigated and discussed with the emphasis on adlayer formed on etched surface.