摘要
用反胶束法制备了表面修饰 AOT-SO- 3(磺基琥珀酸双 -2 -乙基己酯钠盐的阴离子 )的 Cd S纳米粒子与表面修饰 Py(吡啶 )的 Cd S纳米粒子。采用背相简并四波混频 (DFWM)的方法研究了它们的三阶光学非线性。结果表明当 Cd S纳米粒子表面上的 AOT-SO- 3被 Py取代后 ,其三阶非线性极化率增加 ,这归于表面修饰 Py的Cd S纳米粒子具有长寿命的表面受陷电子 -空穴分离态 ,从而提高了对激子吸收的漂白效率 ,增加了三阶光学非线性。
CdS nanoparticles capped by AOT SO 3 -(anion of surfactant bis (2 ethylhexyl) sulfosuccinate, disodium salt) or pyridine were prepared using reverse micelle method. Their third order optical nonlinearities were studied via a Degenerate Four Wave Mixing (DFWM) technique. Results show that the third order nonlinearity of CdS nanoparticles increases when AOT SO 3 - on the particle surface is exchanged by pyridine. This is attributed to that the pyridine modified CdS nanoparticles possess a surface trapped electron hole separation state with long lifetime which is helpful for bleaching of exciton absorption and therefore enhancing the third order optical nonlinearity of CdS nanoparticles.
出处
《固体电子学研究与进展》
CAS
CSCD
北大核心
2002年第4期436-440,共5页
Research & Progress of SSE
基金
NSF(No.10 0 740 2 3
69890 2 2 5
69890 2 2 0 )
关键词
硫化镉钠米粒子
表面化学修饰
简并四波混频
三阶光学非线性
CdS nanoparticles
surface chemical modification
degenerate four wave mixing (DFWM)
third order optical nonlinearities
