Welcome to a new ICN2 recordes Seminar!

Date: Monday 16 January 2023, 10:30am
Place: ICN2 SEMINAR ROOM, CAMPUS UAB
By Prof. Ernesto Joselevich, Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science Israel  

Hosted by Prof. Jordi Arbiol, Advanced Electron Nanoscopy Group Leader at ICN2.

Abstract: The large-scale assembly of NWs with controlled orientation on surfaces remains one challenge toward their integration into practical devices. During the last decade, we have reported the growth of perfectly aligned, millimeter-long, horizontal NWs of GaN, ZnO, ZnSe, ZnTe, CdSe, CdS, CsPbBr3 and other materials, with controlled crystallographic orientations on different planes of sapphire, SiC, quartz, and spinel. The growth directions and crystallographic orientation of the NWs are controlled by their epitaxial relationship with the substrate, as well as by a graphoepitaxial effect that guides their growth along surface steps and grooves. We demonstrated the massively parallel “self-integration” of NWs into circuits via guided growth and the production of optoelectronic nanosystems, including photodetectors, photodiodes and photovoltaic cells. Systematic studies were performed to map the crystallographic orientations and polarity of epitaxially guided nanowires based on their nonlinear optical response under external electric fields, revealing interesting details about their formation. More systematic studies were aimed at understanding the mechanism of guided nanowire growth based on both in situ and ex situ kinetic studies. Ex situ studies reveal the role of dimensionality in guided growth being controlled by the surface-diffusion of adatoms over the substrate. In situ SEM studies yield beautiful movies of guided nanowires growing in real time, and reveal intricate qualitative and quantitative details of the guided growth mechanism.