Quantum Size Effect in Organometal Halide Perovskite Nanoplatelets.
Organometal halide perovskites have recently emerged displaying a huge potential for not only photovoltaic, but also light emitting applications. Exploiting the optical properties of specifically tailored perovskite nanocrystals could greatly enhance the efficiency and functionality of applications based on this material. In this study, we investigate the quantum size effect in colloidal organometal halide perovskite nanoplatelets. By tuning the ratio of the organic cations used, we can control the thickness and consequently the photoluminescence emission of the platelets. Quantum mechanical calculations match well with the experimental values. We find that not only do the properties of the perovskite, but also those of the organic ligands play an important role. Stacking of nanoplatelets leads to the formation of minibands, further shifting the bandgap energies. In addition, we find a large exciton binding energy of up to several hundreds of meV for nanoplatelets thinner than three unit cells, partially counteracting the blueshift induced by quantum confinement. Understanding of the quantum size effects in perovskite nanoplatelets and the ability to tune them provide an additional method with which to manipulate the optical properties of organometal halide perovskites.
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Jasmina A
JA
Sichert
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Yu
Y
Tong
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Niklas
N
Mutz
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Mathias
M
Vollmer
Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.|Soft Condensed Matter Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Geschwister-Scholl-Platz 1, 80539 Munich, Germany.
Stefan
S
Fischer
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Karolina Z
KZ
Milowska
Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.|Soft Condensed Matter Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Geschwister-Scholl-Platz 1, 80539 Munich, Germany.
Ramon
R
García Cortadella
Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.|Soft Condensed Matter Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Geschwister-Scholl-Platz 1, 80539 Munich, Germany.
Bert
B
Nickel
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Carlos
C
Cardenas-Daw
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Jacek K
JK
Stolarczyk
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Alexander S
AS
Urban
Photonics and Optoelectronics Group, Department of Physics and Center for Nanoscience (CeNS), Ludwig-Maximilians-Universität (LMU) , Amalienstaße 54, 80799 Munich, Germany.|Nanosystems Initiative Munich (NIM), Schellingstraße 4, 80799 Munich, Germany.
Jochen
J
Feldmann
Perovskite; nanoplatelets; photoluminescence; quantum size effect