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Lead‐Free Semiconductors: Soft Chemistry, Dimensionality Control, and Manganese‐Doping of Germanium Halide Perovskites
Author(s) -
Men Long,
Rosales Bryan A.,
Gentry Noreen E.,
Cady Sarah D.,
Vela Javier
Publication year - 2019
Publication title -
chemnanomat
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.947
H-Index - 32
ISSN - 2199-692X
DOI - 10.1002/cnma.201800497
Subject(s) - halide , doping , semiconductor , manganese , perovskite (structure) , materials science , germanium , lattice (music) , nanotechnology , chemistry , inorganic chemistry , crystallography , optoelectronics , silicon , physics , metallurgy , acoustics
Lead halide perovskites have drawn enormous interest due to their exceptional photovoltaic and optoelectronic properties. However, the heavy metal lead is harmful to humans and the environment resulting in a need for strategies to replace this toxic element. Herein, we report a facile aqueous synthesis of CsGeX 3 (X=I, Br) perovskite nanocrystals with size control achieved by varying the concentration of a cysteammonium halide ligand. We observe a variety of morphologies including pyramidal, hexagonal, and spheroidal. CsGeX 3 nanocrystals undergo a lattice expansion due to partial replacement of Cs + with larger cysteNH 3 + cations into their lattice. We successfully dope Mn 2+ into the CsGeX 3 lattice for the first time with incorporation of up to 29% in bulk and 16% in nano samples. XRD peak shifts and EPR hyperfine splitting strongly indicate that Mn 2+ is doped into the lattice. Our results introduce a new member to the lead‐free halide perovskite family and set the fundamental stage for their use in optoelectronic devices.