Shape Evolution and Single Particle Luminescence of Organometal Halide Perovskite Nanocrystals

Feng Zhu, Iowa State University
Long Men, Iowa State University
Yijun Guo, Iowa State University
Qiaochu Zhu, Iowa State University
Ujjal Bhattacharjee, Iowa State University
Peter M. Goodwin, Los Alamos National Laboratory
Jacob W. Petrich, Iowa State University
Emily A. Smith, Iowa State University
Javier Vela-Becerra, Iowa State University

Reprinted (adapted) with permission from ACS NANO, 9(3); 2948-2959. Doi: 10.1021/nn507020s. Copyright 2015 American Chemical Society.

Abstract

Organometallic halide perovskites CH3NH3PbX3 (X = I, Br, Cl) have quickly become one of the most promising semiconductors for solar cells, with photovoltaics made of these materials reaching power conversion efficiencies of near 20%. Improving our ability to harness the full potential of organometal halide perovskites will require more controllable syntheses that permit a detailed understanding of their fundamental chemistry and photophysics. In this manuscript, we systematically synthesize CH3NH3PbX3 (X = I, Br) nanocrystals with different morphologies (dots, rods, plates or sheets) by using different solvents and capping ligands. CH3NH3PbX3 nanowires and nanorods capped with octylammonium halides show relatively higher photoluminescence (PL) quantum yields and long PL lifetimes. CH3NH3PbI3 nanowires monitored at the single particle level show shape-correlated PL emission across whole particles, with little photobleaching observed and very few off periods. This work highlights the potential of low-dimensional organometal halide perovskite semiconductors in constructing new porous and nanostructured solar cell architectures, as well as in applying these materials to other fields such as light-emitting devices and single particle imaging and tracking.