PEROVSKITE
NANOCRYSTALS
FOR OPTOELECTRONICS
,What are perovskite nanocrystals?
Definition
Perovskite nanocrystals are semiconductor crystals
with typically nanoscale dimensions and a
perovskite-type lattice. In metal halides, the
combination of a relatively soft ionic lattice, strong
light–matter interaction, and accessible colloidal
chemistry enables integrated control over
composition, size, shape, and surface chemistry.
• Emission tunable through halide composition and
size.
• Low-temperature solution processing.
Educational representation of the three-dimensional perovskite lattice.
,ABX₃ formula
Chemical architecture
The ABX₃ formula captures the essential chemistry
of halide perovskites. The A site occupies cavities in
the lattice, the B site forms BX₆ octahedra, and
halide X connects these octahedra. Changing any
of the three sites modifies lattice distortion, phase
stability, band-gap energy, and carrier dynamics.
• A: Cs⁺, FA⁺, or MA⁺.
• B: primarily Pb²⁺; alternatives include Sn²⁺.
Simplified map of the three chemical sites in an ABX₃ perovskite.
, Nanocrystal or film?
Scale and processing
A colloidal nanocrystal is preformed before device
fabrication and remains coated with surface ligands.
A conventional polycrystalline film, by contrast,
crystallizes during deposition. This distinction shifts
performance control: in nanocrystals, surface
chemistry, interparticle spacing, and packing
become as important as crystal composition.
• Crystallization is decoupled from film formation.
• Interfaces between particles control transport.
Conceptual comparison between a polycrystalline film and a nanocrystal
solid.
NANOCRYSTALS
FOR OPTOELECTRONICS
,What are perovskite nanocrystals?
Definition
Perovskite nanocrystals are semiconductor crystals
with typically nanoscale dimensions and a
perovskite-type lattice. In metal halides, the
combination of a relatively soft ionic lattice, strong
light–matter interaction, and accessible colloidal
chemistry enables integrated control over
composition, size, shape, and surface chemistry.
• Emission tunable through halide composition and
size.
• Low-temperature solution processing.
Educational representation of the three-dimensional perovskite lattice.
,ABX₃ formula
Chemical architecture
The ABX₃ formula captures the essential chemistry
of halide perovskites. The A site occupies cavities in
the lattice, the B site forms BX₆ octahedra, and
halide X connects these octahedra. Changing any
of the three sites modifies lattice distortion, phase
stability, band-gap energy, and carrier dynamics.
• A: Cs⁺, FA⁺, or MA⁺.
• B: primarily Pb²⁺; alternatives include Sn²⁺.
Simplified map of the three chemical sites in an ABX₃ perovskite.
, Nanocrystal or film?
Scale and processing
A colloidal nanocrystal is preformed before device
fabrication and remains coated with surface ligands.
A conventional polycrystalline film, by contrast,
crystallizes during deposition. This distinction shifts
performance control: in nanocrystals, surface
chemistry, interparticle spacing, and packing
become as important as crystal composition.
• Crystallization is decoupled from film formation.
• Interfaces between particles control transport.
Conceptual comparison between a polycrystalline film and a nanocrystal
solid.
