摘要
ZnO nanowire-based surface plasmon polariton (SPP) nanolasers with metal-insulator- semiconductor hierarchical nanostructures have emerged as potential candidates for integrated photonic applications. In the present study, we demonstrated an SPP nanolaser consisting of ZnO nanowires coupled with a single-crystalline aluminum (Al) film and a WO 3 dielectric interlayer. High-quality ZnO nanowires were prepared using a vapor phase transport and condensation deposition process via catalyzed growth. Subsequently, prepared ZnO nanowires were transferred onto a single-crystalline Al film grown by molecular beam epitaxy (MBE). Meanwhile, a WO 3 dielectric interlayer was deposited between the ZnO nanowires and Al film, via e-beam technique, to prevent the optical loss from dominating the metallic region. The metal-oxide-semiconductor (MOS) structured SPP laser, with an optimal WO 3 insulating layer thickness of 3.6 nm, demonstrated an ultra-low threshold laser operation (lasing threshold of 0.79 MW cm -2 ). This threshold value was nearly eight times lower than that previously reported in similar ZnO/Al 2 O 3 /Al plasmonic lasers, which were ~2.4 and ~3 times suppressed compared to the SPP laser, with WO 3 insulating layer thicknesses of 5 nm and 8 nm, respectively. Such suppression of the lasing threshold is attributed to the WO 3 insulating layer, which mediated the strong confinement of the optical field in the subwavelength regime.