Honeycomb 2D Covalent Organic Framework

Kagome bands with Dirac cones

A 2D covalent organic framework featuring enantiomorphic kagome bands sandwiched Dirac cones, tunable by B/N substitution to magnetic or narrowband absorbing variants for multifunctional optoelectronics and wavelength-selective devices.

Jinming, Dong · Yang, Lei · Gao, Quan · Xiyang, Zhai · Zhen, Cheng · Li, Dongmei · Liu, Desheng · Bin, Cui

Physica B: Condensed Matter 2025

Specifications

Optical absorption range

{'zh': '1–4', 'en': '1–4'} eV

Bandgap

{'zh': '1.5', 'en': '1.5'} eV

Magnetization

{'zh': '0.857', 'en': '0.857'} μB/hole

Spin splitting

{'zh': '115', 'en': '115'} meV

Absorption peak intensity

{'zh': '250,000', 'en': '250,000'} cm⁻¹

Advantages

Bandgap tunable by atomic substitution

Replacing carbon with boron or nitrogen opens a ~1.5 eV bandgap, switching from metallic to semiconducting behavior.

Doping induces magnetism

Hole-doped 2D-B-(PP2)3 shows 0.857 μB/hole magnetization and 115 meV spin splitting; electron-doped 2D-N-(PP2)3 gives similar results.

Sharp narrowband absorption

B/N derivatives show sharp absorption peaks at 1.8/2.2 eV with intensity ~250,000 cm⁻¹, contrasting the parent's broadband response and suited for wavelength-selective devices.

Applications

• Multifunctional optoelectronics：Switch between broadband/narrowband absorption and magnetic states on one platform, simplifying integration.
• OLEDs：Narrowband sharp absorption enables wavelength-selective emitting or filtering layers.
• 2D materials：Adds a 2D COF with Dirac cones and kagome bands to the 2D materials library.
• Magnetic materials：Magnetism induced by simple doping without transition metal atoms.