## What is/are Colloidal Two Dimensional?

Colloidal Two Dimensional - Colloidal two-dimensional (2D) semiconductor nanocrystals are of great importance due to their remarkable optical and electronic properties.^{[1]}Because of their enhanced quantum confinement, colloidal two-dimensional Ruddlesden-Popper (RP) perovskite nanosheets with a general formula L2[ABX3]n-1BX4 stand as a promising narrow-wavelength blue-emitting nanomaterial.

^{[2]}Colloidal two-dimensional (2D) lead chalcogenide nanoplatelets (NPLs) represent highly interesting materials for near- and short wave-infrared applications including innovative glass fiber optics exhibiting negligible attenuation.

^{[3]}In a previous work, we studied the orientational and directional locking of colloidal two-dimensional clusters with triangular structure driven across a triangular substrate lattice.

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