Abstract
Magnetic semiconductor, europium chalcogenide nanocrystals (EuX: EuO, EuS and EuSe nanocrystals), are characterized by the narrow 4f orbitals that exist as degenerate levels between the conduction band [5d orbitals of Eu (II)] and the valence band (p orbitals of O^<2->, S^<2-> and Se^<2->). The 4f-5d electronic transition and spin configuration of europium chalcogenide lead to significant photomagnetic effects, making these nanocrystals promising candidates as active materials in photo-magnetic devices. In this review, the syntheses and characteristic photophysical properties of europium chalcogenide nanocrystals are introduced. Europium chalcogenide nanocrystals, the three-dimensional (3D) aggregates and arrangements of the europium chalcogenide nanocrystals by an optical trapping and self-assemble techniques are demonstrated here. Europium chalcogenide nanocrystals have great potential in such applications as novel photo-isolators for optical fibers and photo-magnetic devices.
