将PbS超微粒掺进有机物(Flemion)中得到PbS/Flemion复合膜。室温下的线性吸收光谱表明其吸收带边与体相材料相比发生明显兰移,但没有观察到激于吸收峰。用飞秒激光脉冲做光源,用泵浦-探测方法记录了样品的时间分辨光克尔效应信号,据此得到其三阶非线性极化率、响应时间等一些重要数据,并对观察到的实验现象进行了分析讨论。

We have synthesized nanometer-sized PbS clusters embedded in a new kind of polymer(Flemion) film. Their linear optical absorption spectrum was blue-shift from the bulk band-gap but no exciton peaks are abaerved. Using femtosecond laser pulses, we have recorded the time-resolved Kerr transmission signals of the films, from which we got the third-order nonlinear susceptibility and response time. The experimental data are discussed in terms of the quantum confined effect.