TY - JOUR
T1 - Extraordinary Interfacial Stitching between Single All-Inorganic Perovskite Nanocrystals
AU - Gomez, Leyre
AU - Lin, Junhao
AU - De Weerd, Chris
AU - Poirier, Lucas
AU - Boehme, Simon C.
AU - Von Hauff, Elizabeth
AU - Fujiwara, Yasufumi
AU - Suenaga, Kazutomo
AU - Gregorkiewicz, Tom
PY - 2018/2/14
Y1 - 2018/2/14
N2 - All-inorganic cesium lead halide perovskite nanocrystals are extensively studied because of their outstanding optoelectronic properties. Being of a cubic shape and typically featuring a narrow size distribution, CsPbX3 (X = Cl, Br, and I) nanocrystals are the ideal starting material for the development of homogeneous thin films as required for photovoltaic and optoelectronic applications. Recent experiments reveal spontaneous merging of drop-casted CsPbBr3 nanocrystals, which is promoted by humidity and mild-temperature treatments and arrested by electron beam irradiation. Here, we make use of atom-resolved annular dark-field imaging microscopy and valence electron energy loss spectroscopy in a state-of-the-art low-voltage monochromatic scanning transmission electron microscope to investigate the aggregation between individual nanocrystals at the atomic level. We show that the merging process preserves the elemental composition and electronic structure of CsPbBr3 and takes place between nanocrystals of different sizes and orientations. In particular, we reveal seamless stitching for aligned nanocrystals, similar to that reported in the past for graphene flakes. Because the crystallographic alignment occurs naturally in drop-casted layers of CsPbX3 nanocrystals, our findings constitute the essential first step toward the development of large-area nanosheets with band gap energies predesigned by the nanocrystal choice - the gateway to large-scale photovoltaic applications of inorganic perovskites.
AB - All-inorganic cesium lead halide perovskite nanocrystals are extensively studied because of their outstanding optoelectronic properties. Being of a cubic shape and typically featuring a narrow size distribution, CsPbX3 (X = Cl, Br, and I) nanocrystals are the ideal starting material for the development of homogeneous thin films as required for photovoltaic and optoelectronic applications. Recent experiments reveal spontaneous merging of drop-casted CsPbBr3 nanocrystals, which is promoted by humidity and mild-temperature treatments and arrested by electron beam irradiation. Here, we make use of atom-resolved annular dark-field imaging microscopy and valence electron energy loss spectroscopy in a state-of-the-art low-voltage monochromatic scanning transmission electron microscope to investigate the aggregation between individual nanocrystals at the atomic level. We show that the merging process preserves the elemental composition and electronic structure of CsPbBr3 and takes place between nanocrystals of different sizes and orientations. In particular, we reveal seamless stitching for aligned nanocrystals, similar to that reported in the past for graphene flakes. Because the crystallographic alignment occurs naturally in drop-casted layers of CsPbX3 nanocrystals, our findings constitute the essential first step toward the development of large-area nanosheets with band gap energies predesigned by the nanocrystal choice - the gateway to large-scale photovoltaic applications of inorganic perovskites.
KW - EELS
KW - high-resolution TEM
KW - inorganic perovskites
KW - merging
KW - nanocrystals
KW - seamless stitching
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U2 - 10.1021/acsami.7b17432
DO - 10.1021/acsami.7b17432
M3 - Article
AN - SCOPUS:85042092249
VL - 10
SP - 5984
EP - 5991
JO - ACS Applied Materials & Interfaces
JF - ACS Applied Materials & Interfaces
SN - 1944-8244
IS - 6
ER -