  To obtain room temperature ferromagnetic semiconductors is one of big
challenges in science, and also premises essentially to realize room
temperature quantum anomalous Hall effect (QAHE), both of which are quite
expected for a long time. Here we report that, based on first-principles
calculations, PdBr3, PtBr3, PdI3 and PtI3 monolayers are ferromagnetic
semiconductors with possible high temperature QAHE. Monte Carlo simulations
give Curie temperatures 350 K and 375 K for PdBr3 and PtBr3 monolayers,
respectively. These two-dimensional (2D) materials are Chern insulators. The
band gaps of PdBr3 and PtBr3 are 58.7 meV and 28.1 meV with GGA and 100.8 meV
and 45 meV with HSE06, respectively, quite well in favor of observing room
temperature QAHE. The large band gaps were unveiled from multi-orbital electron
correlations. By carefully checking the stability, PdBr3, PtBr3, and PtI3
monolayers are all predicted to be feasible in experiment. The present work
sheds new light on developing promising spintronic devices by using the room
temperature ferromagnetic semiconductors, and dissipationless devices by
applying room temperature QAHE.
