| Project/Area Number |
12650005
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied materials science/Crystal engineering
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
BABA Motoyoshi The University of Tokyo, Institute for Solid State Physics, Research Associate, 物性研究所, 教務職員 (60159077)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YOSHITA Masahiro The University of Tokyo, Institute for Solid State Physics, Research Associate, 物性研究所, 助手 (30292759)
AKIYAMA Hidefumi The University of Tokyo, Institute for Solid State Physics, Associate professor, 物性研究所, 助教授 (40251491)
MORITA Makoto Seikei university, Faculty of Engineering, Professor, 工学部, 教授 (70054351)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
|
|---|
| Keywords | Nanocrystal / Ultraviolet sub-pico second laser / Slo-gel silica glass / Blue luminescenece materials / Ultrashort time resolution spectroscopy / 紫外サブピコ秒パルス |
|---|
| Research Abstract |
We developed the new ultraviolet laser source system. The wavelength of the laser ranges from 290 nm to 31 nm in ultraviolet region by frequency-doubling the cavity-dumped picosecond dye laser by use of harmonic crystal BBO. The laser light excited the various samples and we observed the blue luminescence by photon counting. We used TAC (time-to-amplitude converter) system to observe ultrafast fluorescence decay.
1. Silicon carbide (SiC) has recently been receiving more attention as a wide-band-gap semiconductor with possible application a a high-temperature, high-power, high-speed, and radiation-resistant device material. The resonant Raman spectra of 4H-SiC, 6H-SiC, and 15R-SiC were measured from visible excitation to ultraviolet excitation. A selective enhancement of the intensities of the folded longtudinal phonon modes relative to the nonfolded longitudinal optical phonon mode was found. We explain this mechanism by a bond-Raman polarizability model with a one-dimensional lattice dynamics model.
2. Thin sol-gel silica films doped wigh semiconductor nanocrystals xZr02/100-xCdS : Mn2 + Eu3 + or other transition metals were prepared to clarify emission centers by measurements of luminescence, time-resolved luminescence, excitation spectra and deca profiles in the temperature range between 10 and 300K. We found the decay curve of those doped films showed very short decay times of about 10ns or shorter at room temperature under an excitation of sub-picosecond 300 nm ultraviolet laser light, which are two orders of magnitudes faster than those reported in hexagonal-ZnS : Mn2 + bulk phosphors. Surface enhancement and/or quenching effects on zirconia films present new evidence of furface trapping of recombintaion centers in this system.
|
