1104965_Kanatzidis

1. Flexible Polar Nanowires with Strong Nonlinear Optical Second Harmonic GenerationMercouri G. Kanatzidis, Northwestern University, DMR 1104965 The compound Cs5BiP4Se12 naturally forms long flexible fibers. The packing mode of the [Bi(P2Se6)2]5 molecules and the weak Se∙∙∙Se interactions between molecules is responsible for the self-formed long flexible nanowires which organize into fibers. Cs5BiP4Se12 is widely transparent in the near-/mid IR, ranging from 18.8 to 0.67 mm, and it exhibits a relatively strong SHG response, which is ~2 times larger than that of AgGaSe2. The compound is a nearly direct band gap semiconductor, with a very sharp absorption edge, and melts congruently. This material is promising for further in-depth investigations of its NLO properties.

2. Flexible Polar Nanowires with Strong Nonlinear Optical Second Harmonic GenerationMercouri G. Kanatzidis, Northwestern University, DMR 1104965 NLO materials with high conversion efficiencies can enable efficient light processing and may enable a number of communication and biomedical applications. A patent application has been filed. The project involves the participation of female students at the graduate and undergraduate levels. One PhD student (J. Mertz) having been funded by this grant graduated and now employed in the startup company Kurion, Inc. Technological impact: NLO effects in the infrared region allow all-optical high-capacity communication networks, tunable mid-infrared light sources that are hard to reach by other means, remote sensing and medical diagnostics. The nanowire morphology in Cs5BiP4Se12 emerges from the specific intermolecular secondary interactions, which could not be predicted a priori. This discovery implies that innate one- or two-dimensional nanostructures may be rationally approached from crystal structure considerations.