Photoluminescence Blinking of Single-Crystal Methylammonium Lead Iodide Perovskite Nanorods Induced by Surface Traps.
Photoluminescence (PL) of organometal halide perovskite materials reflects the charge dynamics inside of the material and thus contains important information for understanding the electro-optical properties of the material. Interpretation of PL blinking of methylammonium lead iodide (MAPbI3) nanostructures observed on polycrystalline samples remains puzzling owing to their intrinsic disordered nature. Here, we report a novel method for the synthesis of high-quality single-crystal MAPbI3nanorods and demonstrate a single-crystal study on MAPbI3PL blinking. At low excitation power densities, two-state blinking was found on individual nanorods with dimensions of several hundred nanometers. A super-resolution localization study on the blinking of individual nanorods showed that single crystals of several hundred nanometers emit and blink as a whole, without showing changes in the localization center over the crystal. Moreover, both the blinking ON and OFF times showed power-law distributions, indicating trapping-detrapping processes. This is further supported by the PL decay times of the individual nanorods, which were found to correlate with the ON/OFF states. Furthermore, a strong environmental dependence of the nanorod PL blinking was revealed by comparing the measurements in vacuum, nitrogen, and air, implying that traps locate close to crystal surfaces. We explain our observations by proposing surface charge traps that are likely related to under-coordinated lead ions and methylammonium vacancies to result in the PL blinking observed here.
Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium.
Haifeng
H
Yuan
Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium.
Elke
E
Debroye
Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium.
Giorgio
G
Caliandro
Department of Chemistry, KU Leuven , Celestijnenlaan 200F, B-3001 Leuven, Belgium.
Kris P F
KP
Janssen
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Heverlee, Belgium.
Jordi
J
van Loon
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Heverlee, Belgium.
Christine E A
CE
Kirschhock
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Heverlee, Belgium.
Johan A
JA
Martens
Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium; RIES, Hokkaido University, N20W10, Kita-Ward, Sapporo 001-0020, Japan.
Johan
J
Hofkens
Centre for Surface Chemistry and Catalysis, KU Leuven , Kasteelpark Arenberg 23, 3001 Heverlee, Belgium.
Maarten B J
MB
Roeffaers