Affiliation:
1. Department of Physics and Astronomy University of California-Davis One Shields Avenue Davis CA 95616 USA
2. Center for Integrated Nanotechnology Los Alamos National Laboratory Los Alamos NM 87545 USA
3. Department of Physics University of California, Merced 5200 Lake Road Merced CA 95343 USA
4. Molecular Foundry Lawrence Berkeley Laboratory 67 Cyclotron Road Berkeley CA 94720 USA
5. Department of Chemistry and Biochemistry Florida State University 600 W College Avenue Tallahassee FL 32306 USA
Abstract
1D organic metal halide hybrids (OMHHs) exhibit strongly anisotropic optical properties, highly efficient light emission, and large Stokes shift, holding promise for novel photodetection and lighting applications. However, the fundamental mechanisms governing their unique optical properties and in particular the impacts of surface effects are not understood. Herein, 1D C4N2H14PbBr4 by polarization‐dependent time‐averaged and time‐resolved photoluminescence (TRPL) spectroscopy, as a function of photoexcitation energy, is investigated. Surprisingly, it is found that the emission under photoexcitation polarized parallel to the 1D metal halide chains can be either stronger or weaker than that under perpendicular polarization, depending on the excitation energy. The excitation‐energy‐dependent anisotropic emission is attributed to fast surface recombination, supported by first‐principles calculations of optical absorption in this material. The fast surface recombination is directly confirmed by TRPL measurements, when the excitation is polarized parallel to the chains. The comprehensive studies provide a more complete picture for a deeper understanding of the optical anisotropy in 1D OMHHs.
Funder
Division of Materials Research
Basic Energy Sciences
Air Force Office of Scientific Research
Subject
General Earth and Planetary Sciences,General Environmental Science