Quantum mechanics

Scale (ratio)

Engineering

Materials science

Cartography

Layer (electronics)

Conductive atomic force microscopy

Perovskite (structure)

Nano-

Chemical engineering

Kelvin probe force microscope

Band gap

Grain boundary

Physics

Atomic force microscopy

Nanotechnology

Geography

Microstructure

PEDOT:PSS

Solar cell

Composite material

Nanocrystal

Crystallography

Chemistry

Atomic units

Nanoscopic scale

Optoelectronics

ACS Applied Materials & Interfaces

Colloidal synthesized cubic α-CsPbI3 perovskite nanocrystals having a smaller lattice constant (a = 6.2315 Å) compared to the standard structure, and nanoscale mapping of their surfaces are reported to achieve superior photovoltaic performance under 45-55% humidity conditions. Atomic scale transmission electron microscopic images have been utilized to probe the precise arrangement of Cs, Pb, and I atoms in a unit cell of α-CsPbI3 NCs, which is well supported by the VESTA structure. Theoretical calculation using density functional theory of our experimental structure reveals the realization of direct band to band transition with a lower band gap, a higher absorption coefficient, and stronger covalent bonding between the Pb and I atoms in the [PbI6]4- octahedral, as compared to reported standard structure. Nanoscale surface mapping using Kelvin probe force microscopy yielding contact potential difference (CPD) and conductive atomic force microscopy for current mapping have been employed on α-CsPbI3 NCs films deposited on different DMSO doped PEDOT:PSS layers. The difference of CPD value under dark and light illumination suggests that the hole injection strongly depends on the interfaces with PEDOT:PSS layer. The carrier transport through grain interiors and grain boundaries in α-CsPbI3 probed by the single-point c-AFM measurements reveal the excellent photosensitivity under the light conditions. Finally, inverted perovskite solar cells, employing α-CsPbI3 NCs film as an absorber layer and PEDOT:PSS layer as a hole transport layer, have been optimized to achieve the highest power conversion efficiency of 10.6%, showing their potential for future earth abundant, low cost, and air stable inverted perovskite photovoltaic devices.

Atomic-Scale Imaging and Nano-Scale Mapping of Cubic α-CsPbI<sub>3</sub> Perovskite Nanocrystals for Inverted Perovskite Solar Cells

Atomic-Scale Imaging and Nano-Scale Mapping of Cubic α-CsPbI3 Perovskite Nanocrystals for Inverted Perovskite Solar Cells

Atomic-Scale Imaging and Nano-Scale Mapping of Cubic α-CsPbI₃ Perovskite Nanocrystals for Inverted Perovskite Solar Cells