Articolo in rivista, 2009, ENG, 10.1021/nn900558q

Unpredicted Nucleation of Extended Zinc Blende Phases in Wurtzite ZnO Nanotetrapod Arms

Lazzarini L. a; Salviati G. a; Fabbri F. a; Zha M. a; Calestani D. a; Zappettini A. a; Sekiguchi T. b; Dierre B. b

a CNR-IMEM, Parma, Italy b NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan

Tailoring the structural and electronic properties of 3D nanostructures via bottom-up techniques would pave the way for novel low-cost applications. One of such possibilities is offered by ZnO branched nanostructures like tetrapods, that have recently attracted attention for nanodevice applications from nanoelectronics to drug delivery. The conventional picture is that ZnO arms are thermodynamically stable only in the wurtzite phase. Here, we provide the first experimental evidence of unpredicted extended zinc blend phases (50-60 nm long) embedded in the arms of ZnO wurtzite tetrapods. In particular, decisive evidence is obtained from the one-to-one correlation between high lateral resolution cathodoluminescence spectroscopy, monochromatic contrast maps, and atomic resolution transmission electron microscopy images of ZnO single TIPS. This observation is not specific to ZnO and can have a general validity for the understanding of the nucleation mechanisms in semiconducting 3D nanostructures for device applications.

ACS nano 3 (10), pp. 3158–3164

Keywords

zinc oxide, tetrapods, cubic phase, cathodoluminescence, HRTEM

CNR authors

Fabbri Filippo, Lazzarini Laura, Zha Mingzheng, Zappettini Andrea, Calestani Davide, Salviati Giancarlo

CNR institutes

IMEM – Istituto dei materiali per l'elettronica ed il magnetismo