1993 Fiscal Year Final Research Report Summary
Femtosecond spectroscopy for the dynamics of relaxation of excitons in solids with strong electron-phonon coupling
| Project/Area Number |
04452040
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
固体物性
|
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
TANIMURA Katsumi Nagoya Univ.Sci.Assoc.Prof., 理学部, 助教授 (00135328)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Arao Nagoya Univ.Eng.Prof., 工学部, 教授 (50159068)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Keywords | self-trapping / excitons / femtosecond spectroscopy / lattice relaxation / F-H pair / alkali halides / fluorites / SiO2 |
|---|
| Research Abstract |
Lattice relaxation of excitons in alkali halides, fluorites, and SiO_2 have been studies by means of time-resolved spectroscopy in femtosecond time regime. Our new findings and results obtained in this study are summarized as follows :
(1)Initial formation yields of F-H pairs and triplet self-trapped excitons, STEs, in alkali halides show a clear complementary relation.
(2)Optical transition energies of self-trapped holes in amorphous SiO_2 have been determined.
(3)Luminescence from the singlet STE in SiO_2 have been identified for the first time.
(4)Self-trapping processes of holes in KBr and KI have been resolved for the first time. In particular, holes in KI are self-trapped into the well-known V_k center via an one-center type self-trapped state.
(5)Initial process of F-center formation in alkali bromides has been found to involve two different pathways ; one directly from the electron-hole pairs under relaxation and the other via the off-center instability from the on-center STEs.
(6)Relaxation of electron-hole pairs in CaF_2 has been observed for the first time in femtosecond time regime. The relaxation pathways are found to be similar to those in alkali halides.
|
Research Products
(8 results)
