摘要
利用静电自组装技术,以生物大分子材料壳聚糖杂化处理具有稳定结构的CdSe/ZnS核/壳量子点,形成复合多层薄膜.与薄膜的吸收谱线比较,在375nm飞秒激光激发下测量的量子点的光致发光谱存在Stokes位移.采用Z扫描技术,利用790nm飞秒激光研究了其三阶非线性吸收和折射特性,发现饱和吸收信号来自CdSe/ZnS量子点,而自聚焦的折射信号则部分来自壳聚糖.测出多层膜的三阶非线性系数分别是β=6·5×10^(-6)cm/W,n2=1·5×10^(-10)cm2/W.
Biopolymer-CdSe/ZnS core-shell quantum dot hybrid films were prepared using self-assembly technique. Compared with the absorbance spectrum, the photoluminescence excited by laser with λ= 395nm has Stokes shift. The third-order nonlinear optical properties of biopolymer-CdSe/ZnS film were studied by Z-scan setup with femtosecond laser at 790nm. It is found that the nonlinear absorptive signal partially originates from Cde/ZnS quantum dots while the nonlinear refractive signal partially originates from biopolymer chitosan. The magnitudes of them are measured to be ,β = 6.5 × 10^-6cm/W and n2 = 1.5 ×10^-10cm^2/W, respectively.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第2期753-757,共5页
Acta Physica Sinica
基金
国家自然科学基金(批准号:10474075)资助的课题.~~
关键词
CdSe/ZnS量子点
非线性性能
光致发光谱
CdSe/ZnS core-shell quantum dots, nonlinear optical property, photoluminescence
