Organic two-dimensional van der Waals heterostructures.

Programmable lattice engineering in organic 2D van der Waals heterostructures achieves high rectification ratios over 10^7, enabling advanced optoelectronic applications.

• Why it matters: Organic 2D heterostructures have been limited by weak, non-directional interlayer interactions, hindering precise control over lattice alignment and emergent electronic properties.
• What they did: The authors developed a bottom-up, layer-by-layer assembly method on water surfaces to create chemically distinct 2D polymers with controlled lattice registry, sequence, and thickness, including both lattice-matched and mismatched systems.
• The result: Structural and spectroscopic analyses show effective charge separation and built-in electric fields at interfaces, with device rectification ratios decreasing as lattice mismatch increases, paving the way for tunable organic electronic devices.