| Project/Area Number |
08454077
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | KYOTO UNIVERSITY (1997)
The University of Tokyo (1996) |
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Principal Investigator |
HASUO Masahiro Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (40218433)
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| Co-Investigator(Kenkyū-buntansha) |
NAGASAWA Nobukata University of Tokyo, School of Science, Professor, 理学系研究科, 教授 (50004437)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | exciton / semiconductor / Cu_2O / Rydberg state / nonlinear optics / diamagnetic shift / photo conductivity / photo voltaic effect |
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| Research Abstract |
Cu_2O is one of model materials in which Wannier exciton series are clearly observed. It has been found from high resolution spectroscopic studies sofar that exciton states of large principle quantum numbers(Rydberg exciton state)are stable in high quality Cu_2O crystals. One the other hand, ls-excitons in Cu_2O gather much notice due to the Bose-Einstein condensation(BEC)of excitons. The purpose of this work is to examine the Ryberg exciton states and the ls exciton state with developing a new spectroscopy system of high precision. Achievements of this work are as follows ;
1.A high repetition(^-lkHz)frequency tunable IR laser excited by a CW Q-swiched YAG laser has been developed. A spectroscopy system of high resolution and high sensitivity has been also developed using a high resolution monochromator and a CCD camera.
2.Diamagnetic shifts of 3[s-d]and 4[s-d]exciton doublet states have been measured to identifys and dexciton.
3.Optical processes associated with the two-photon excitation of ls-ortho-excitons have been measured and discussed in view of the BEC of extions.
4.Relaxation processes of ls-ortho-excitons have been examined from analyzes of emission spectra associated with the two-photon excitation of ls-ortho-excitons.
5.A system to measure photo conductivity and photo-voltaic effects of Cu_2O at liquid helium temperature has been developed.
6.Photo-voltaic effects of Cu_2O has been measured. One-and two-photon photo-voltaic spectroscopy has been demonstrated and its usefulness has been verified.
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