Interaction between excitons determines the non-linear response of nanocrystals
- 作者：Mayrose R. Salvador ; P. Sreekumari Nair ; Minhaeng Cho ; Gregory D. Scholes
- 关键词：Nanocrystal ; Quantum dot ; Photo echo ; Non-linear response ; Laser ; Ultrafast ; CdSe
- 刊名：Chemical Physics
- 出版年：2008
- 期刊代码：18_03010104
- 类别：ch
- 出版时间：23 June 2008
- 卷：350
- 期：1-3
- 页码：56-68
- 文件大小：686 K
摘要
The non-linear response of semiconductor quantum dots is investigated using three-pulse photon echo peak shift (3PEPS) experiments and simulations. The third-order non-linear response is modeled by a three-level system, utilizing Brownian oscillators to model the line-broadening functions. Our results show that biexciton formation and exciton–exciton scattering significantly influence the non-linear response of quantum dots. The exciton to biexciton excited state absorption pathways are also investigated for quantum dots with different crystal structures. Our calculations suggest that the probability of excited state absorption to the biexcitonic state is higher for zinc-blende structured nanocrystals.