External egg morphology of two parthenogenetic species of the genus Dahlica Enderlein (Lepidoptera: Psychidae).

The egg chorion morphologies of Dahlica triquetrella (Hbner, 1813) and Dahlica lichenella (Linnaeus, 1761) are described. These two species well differ from each other by diameter of the micropyle, by number of micropyle pores, and by diameter of the micropyle rosette.

Negatively Charged Excitons in CdSe Nanoplatelets.

The low-temperature emission spectrum of CdSe colloidal nanoplatelets (NPLs) consists of two narrow lines. The high-energy line stems from the recombination of neutral excitons. The origin of the low-energy line is currently debated.

Addressing the exciton fine structure in colloidal nanocrystals: the case of CdSe nanoplatelets.

We study the band-edge exciton fine structure and in particular its bright-dark splitting in colloidal semiconductor nanocrystals by four different optical methods based on fluorescence line narrowing and time-resolved measurements at various temperatures down to 2 K. We demonstrate that all these methods provide consistent splitting values and discuss their advances and limitations. Colloidal CdSe nanoplatelets with thicknesses of 3, 4 and 5 monolayers are chosen for experimental demonstrations.