Size Dependence of the Exciton Transitions in Colloidal CdTe Quantum Dots

作者：Groeneveld Esther; Delerue Christophe; Allan Guy; Niquet Yann Michel; Donega Celso de Mello^*

来源：Journal of Physical Chemistry C, 2012, 116(43): 23160-23167.

DOI：10.1021/jp3080942

In this paper, we present a detailed investigation of the size dependence of the optical transitions of colloidal CdTe QDs ranging in diameter from 2.9 to 14.8 nm. The energy integrated absorption cross section per CdTe unit is investigated in detail for the lowest two exciton transitions (1S(3/2(h))-1S((e)) and 2S(3/2(h))-1S((e))) and shown to increase with decreasing size, although the size dependence of the 2S(3/2(h))- 1S((e)) is less pronounced. The experimental absorption spectra are compared to spectra calculated by using a tight-binding approach. The calculations were carried out with electron-hole configuration interaction (CI) and without (single-particle, SP). The optical absorption spectra calculated by using the CI approach are in excellent agreement with the experiment, as well as the evolution of the optical gap and the optical transitions with nanocrystal size.

• 出版日期2012-11-1
• 单位中国地震局