Enhanced Direct Exchange Interaction and Hybridization by Single-Atom Linkers for High Curie Temperature and Superior Visible-Light Harvesting in Cr<sub>3</sub>(CN<sub>3</sub>)<sub>2</sub>
Xiaofeng Liu, Haidi Wang, Zhao Chen, Weiduo Zhu, Zhongjun Li, Wei Hu, Hai-Xiao Xiao, Xiao Cheng Zeng
Abstract
Designing two-dimensional (2D) ferromagnetic (FM) semiconductors with elevated Curie temperature, high carrier mobility, and strong light harvesting is challenging but crucial to the development of spintronics with multifunctionalities. Herein, we show first-principles computation evidence of the 2D metal–organic framework Kagome ferromagnet Cr 3 (CN 3 ) 2 . Monolayer Cr 3 (CN 3 ) 2 is predicted to be an FM semiconductor with a record-high Curie temperature of 943 K owing to the use of a single-atom linker (N), which results in strong direct d–p exchange interaction and hybridization between d yz / xz and p z of Cr and N, as well as excellent matching characteristics in energy and symmetry. The single-atom linker structural feature also leads to notable band dispersion and a relatively high carrier mobility of 420 cm 2 V –1 s –1 . Moreover, under the in-plane strain, 2D Cr 3 (CN 3 ) 2 can be tuned to possess a strong visible-light-harvesting functionality. These novel properties render monolayer Cr 3 (CN 3 ) 2 a distinct 2D ferromagnet with high potential for the development of multifunctional spintronics.