1987 Fiscal Year Final Research Report Summary
Research on Electronic States in Clusters
| Project/Area Number |
59460030
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物性一般（含極低温･固体物性に対する理論）
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| Research Institution | University of Tsukuba |
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Principal Investigator |
TOSHIHIRO ARAI Inst. of Appl. Phys,. Univ. of Tsukuba, Prof., 物理工学系, 教授 (10015745)
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| Co-Investigator(Kenkyū-buntansha) |
AKIO HIRAKI Dep. of Electrical Engineering, Osaka Univ,. Prof., 工学部, 教授 (50029013)
小川 力 筑波大学, 物理工学系, 講師
大成 誠之助 筑波大学, 物理工学系, 助教授
TSUTOMU OGAWA Inst. of Appl. Phsy,. Univ. of Tsukuba, Lecturer, 物理工学系, 教授 (10025364)
SEINOSUKE ONARI Inst. of Appl. Phys., Univ. of Tsukuba, Ass. Prof. (KAWAZOE,Yosh)
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| Project Period (FY) |
1984 – 1986
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| Keywords | microcluster / cluster, / Quasi-microcluster / microcrustal / quari-crystal / intrinsic absorption edge / surface effect |
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| Research Abstract |
The apparatus which was constructed from two vaccum rooms and a diffrerntial pumping system was bulided up to make a cluster veam and to measure some optical properties of clusters in the beam. Vaporization of sample was accomplished an electron gun in small Cu-botttle which had a various shaped nozzle. Small cluster beam was introduced into another vacuum room, in which a pair of 30cm-long parallel mirrors was settled for measurements of potical absorption, optical scattering and optical emission etc. This room also apparatus for collecting od clusters. According to result of preliminary experiment on Ag-cluster beam, the plasma absorption was not observed. The size dependence of photoluminescence of CdSe cluster which was gathered from a cooled substrate was measured. The two lines originating exciton and donor-acceptor pair, respectively, were observed in large size clysters. However, the intensity of excition line decreased with decreasing cluster size and the line could be hardly
… More
observed in cluster size less then 4nm in diameter. This phenomenon is interpreted to be due to the inelastic scattering of the electron in surface zone of cluster. The small size cluster had zincblend structure instead of wurtzite structure in bulk. It may originate from increase of the ratio of the surface to volume. Size dependences of relaxation mechanism of optically excited electrons in CdS clusters were also investigated by means of photoacoustic and Iuminescence spectroscopy. Non-radiative recombination rate increases with decreasing cluster size. One of the member has worked on hydrogenrated Si microcrystalline film by taking second derivative modes of infrared absorption. Two absorption peaks due to SiH on Si(111) and Si (110) surfaces of the mycrocrystalline grains in the film, respectively, near 2100 cm ^<-1> were clarified and the presence of both the symmetric and asymmetric modes of stretching in SiH_2 on Si(100) and SiH_3 on Si(111) and Si(110) surfaces was assigned successfully. Further, one of the member has studied theoretically on the structure of a quasi-crystal. A 3-D penrose transformation is found. The expansion rates <tau> in linear dimension and <tau>^9 in volume, are by far the larger than <tau> and <tau>^3 respectively ever believed. The transformation decides only the skeleton uniquely, leavin some other degrees of freedom undecicded. It strikinglydiffers from deterministic 2-D case. Many other properties are common with the 2-D case. This transformation is helpful in under standing the quasi-crystal structure. Less
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Research Products
(19 results)
