Chapter 11
The Confinement and Migration
of Charge-Carriers in Lead Halide
Perovskites
Sushant Ghimire, Lata Chouhan, and Vasudevanpillai Biju
Abstract With the growing success of halide perovskites as functional materials
in solar cells, LEDs, and lasers, studies are progressing to reveal their optical and
charge-carrier properties. This chapter describes the consequences of charge-carrier
generation, stabilization, and recombination in perovskite nanocrystals, quantum
dots, and their assemblies. The strong confinement of charge-carriers in perovskite
quantum dots causes photoluminescence blinking with distinct ON and OFF events,
which is due to photocharging and ultrafast Auger nonradiative recombination. Such
a blinking with long OFF periods suppresses superoxide generation and oxidation of
perovskites. When perovskite nanocrystals and quantum dots are closely-packed into
superlattices, the carrier confinement is broken due to the narrowing of inter-particle
energy levels and the formation of minibands that allow for carrier migration. This
results in unexpectedly delayed photoluminescence at low intensities of excitation
light, whereas at high intensities of excitation light, the ultrafast radiative recombination of charge-carriers occurs. These properties of quantum dots, nanocrystals, and
assemblies of perovskites are important to be considered during the construction of
devices such as solar cells, LEDs, and lasers.
Keywords Halide perovskites · Nanocrystals · Quantum dots · Perovskite
assemblies · Single particle studies
Sushant Ghimire and Lata Chouhan: Equal contribution.
S. Ghimire · L. Chouhan · V. Biju
Graduate School of Environmental Science, Hokkaido University, N10, W5, Sapporo, Hokkaido
060-0810, Japan
e-mail: ghimiresushant@eis.hokudai.ac.jp
V. Biju (B)
Research Institute for Electronic Science, Hokkaido University, N20, W10, Sapporo, Hokkaido
001-0020, Japan
e-mail: biju@es.hokudai.ac.jp
© Springer Nature Singapore Pte Ltd. 2020
H. Miyasaka et al. (eds.), Photosynergetic Responses in Molecules
and Molecular Aggregates, https://doi.org/10.1007/978-981-15-5451-3_11
197
The Confinement and Migration
of Charge-Carriers in Lead Halide
Perovskites
Sushant Ghimire, Lata Chouhan, and Vasudevanpillai Biju
Abstract With the growing success of halide perovskites as functional materials
in solar cells, LEDs, and lasers, studies are progressing to reveal their optical and
charge-carrier properties. This chapter describes the consequences of charge-carrier
generation, stabilization, and recombination in perovskite nanocrystals, quantum
dots, and their assemblies. The strong confinement of charge-carriers in perovskite
quantum dots causes photoluminescence blinking with distinct ON and OFF events,
which is due to photocharging and ultrafast Auger nonradiative recombination. Such
a blinking with long OFF periods suppresses superoxide generation and oxidation of
perovskites. When perovskite nanocrystals and quantum dots are closely-packed into
superlattices, the carrier confinement is broken due to the narrowing of inter-particle
energy levels and the formation of minibands that allow for carrier migration. This
results in unexpectedly delayed photoluminescence at low intensities of excitation
light, whereas at high intensities of excitation light, the ultrafast radiative recombination of charge-carriers occurs. These properties of quantum dots, nanocrystals, and
assemblies of perovskites are important to be considered during the construction of
devices such as solar cells, LEDs, and lasers.
Keywords Halide perovskites · Nanocrystals · Quantum dots · Perovskite
assemblies · Single particle studies
Sushant Ghimire and Lata Chouhan: Equal contribution.
S. Ghimire · L. Chouhan · V. Biju
Graduate School of Environmental Science, Hokkaido University, N10, W5, Sapporo, Hokkaido
060-0810, Japan
e-mail: ghimiresushant@eis.hokudai.ac.jp
V. Biju (B)
Research Institute for Electronic Science, Hokkaido University, N20, W10, Sapporo, Hokkaido
001-0020, Japan
e-mail: biju@es.hokudai.ac.jp
© Springer Nature Singapore Pte Ltd. 2020
H. Miyasaka et al. (eds.), Photosynergetic Responses in Molecules
and Molecular Aggregates, https://doi.org/10.1007/978-981-15-5451-3_11
197