Design and synthesis of colloidal nanocrystal heterostructures with tetrapod morphology

An approach for a high yield synthesis of tetrapod heterostructures with a zinc blend ZnTe core and wurtzite CdSe or CdS arms was investigated. These branched heterostructures could be obtained with a high yield and uniform shape sorting. An important factor in the formation of tetrapod morphology is that the zinc blend structure is adopted in the nucleation stage while the wurtzite structure is preferred during crystal growth. High resolution transmission electron microscopy (HRTEM) was employed for a more detailed structural characterization of the tetrapod shaped heterostructure nanocrystals. The results obtained from the optical absorption spectrum of the ZnTe/CdSe tetrapods revealed a pronounced absorption band around 650 nm.