Grant-in-Aid for Scientific Research (B).
|Allocation Type||Single-year Grants|
|Research Institution||SHIZUOKA UNIVERSITY|
NAGAMURA Toshihiko Shizuoka University, Professor, 電子工学研究所, 教授 (90117200)
KAWAI Hideki Shizuoka University, Research Associate, 電子工学研究所, 助手 (80324341)
SAKAGUCHI Hiroshi Shizuoka University, Associate professor, 電子工学研究所, 助教授 (30211931)
KISCH Horst エルランゲンーニュールンベルグ大学, 教授
MULVANEY Pau メルボルン大学, 化学科, 講師
GRIESER Fran メルボルン大学, 化学科, 助教授
|Project Period (FY)
1998 – 2000
Completed(Fiscal Year 2000)
|Budget Amount *help
¥8,500,000 (Direct Cost : ¥8,500,000)
Fiscal Year 2000 : ¥3,100,000 (Direct Cost : ¥3,100,000)
Fiscal Year 1999 : ¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1998 : ¥2,800,000 (Direct Cost : ¥2,800,000)
|Keywords||Cds nano-particles / ultrafast photoresponses / electronic state changes / second oreder nonlinear optical coefficient / excited triplet state / guided mode thin films / photon-mode ultrafast modulation / 蛍光活性化CdS超微粒子 / フェムト秒レーザー / エキシトン発光 / サブピコ秒応答 / 電子と正孔の直接再結合 / 超高速光応答半導体 / ナノメーター / 過渡ブリーチング / エキシトン / トラップサイト|
This project dealt primarily with the construction and examination of ultrafast photoresponses of several organized molecular assemblies, including size-quantized CdS nano-particles and ion-pair charge-trans- fer complexes, evaluation of nonlinear optical properties of organic molecules at the excited state and also with application of such photoresponses materials in all-optical data processing. Scientists from Australia, Germany and Japan collaborated in this study, with the main objectives being,
1) Formation of size-quantized and highly luminescent CdS nano-particles in anionic polymer films, and in aqueous solutions ; 2) Control of CdS nano-particle sizes and their surface treatments to considerably decrease defects or traps ; 3) Measurement of ultrafast photoresponses by femtosecond (fs) laser flash photolysis, and an examination of the effect of size and surface conditioning on the dynamics of the photoresponse ; 4) Construction of novel guided wave mode geometry containing these
photoresponsive materials in order to apply them in parallel optical data processing based on photoinduced ultrafast changes of absorption, refractive index or luminescence.
Followings are some of main results obtained from the present study, which will contribute a great deal to construct all-optical data processing in the near future based on ultrafast photoresponses of organic molecules and inorganic nano-particles.
1) Preparation of CdS nano-particles with a diameter of 3.7-5.4 nm showing very strong exciton lumines- cence and none or very weak, if any, defect luminescence in aqueous solutions.
2) Observation of an extremely fast (τ<0.7 ps) recovery component after exciton bleaching upon fs laser excitation of luminescence activated CdS nano-particles.
3) Evaluation of the second order nonlinear optical constant, hyperpolarizability, at the excited state.
4) Demonstration of ultrafast parallel optical modulation of reflected light by guided mode geometry containing organic dyes upon ns-fs laser excitation. Less