ZnO Nanowires on Single-Crystalline Aluminum Film Coupled with an Insulating WO3 Interlayer Manifesting Low Threshold SPP Laser Operation

Abstract

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 WO3 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 WO3 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 WO3 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/Al2O3/Al plasmonic lasers, which were ≈2.4 and ≈3 times suppressed compared to the SPP laser, with WO3 insulating layer thicknesses of 5 nm and 8 nm, respectively. Such suppression of the lasing threshold is attributed to the WO3 insulating layer, which mediated the strong confinement of the optical field in the subwavelength regime.

Superb Low Threshold Surface-Plasmon Polariton ZnO Nanolasers on an Aluminum Film with Tailored MoO3 and Ta2O5 Dielectric Interlayers of Varied Thickness

“…Table 1. Dielectric Constant and Lasing Threshold for Nanolasers with Different Dielectric Interlayers 13,18,36 The Table 1 summarizes the lasing threshold of the ZhDlA plasmonic nanolaser system with disparate dielectric constants compared with the other reported nanolaser system. The dielectric constant describes the capacitive charge, which can retain electrical energy created.…”

“…In plasmonic nanolasers, surface plasmons coupled with photons confine light to the deep subwavelength area at the metal–dielectric material interface, enhancing light–matter interactions and supporting lasing modes much smaller than the optical wavelength. − As a result, the dimension of the plasmonic cavity can be compressed to the nanometer scale, ultimately enabling the simultaneous amplification of photons. Various types of nanolasers have been demonstrated that possess many attributes for an on-chip light source such as low thresholds, ,− room-temperature operation, − and dense-integration capability. Widespread efforts have been made to control the energy confinement between a metal–dielectric interface in metal–oxide–semiconductor structures.…”

“…The ZnO nanowires were synthesized by a CVD method with gold nanoparticles acting as the catalyst in a horizontal three-zone furnace, as reported in a previous paper. 18 The diameters of nanowires, sizedependent of Au nanoparticles, are 100−150 nm. The length of nanowires is approx.…”

Elucidation of Strain-Dependent, Zinc Oxide Nanorod Response for Nanorod-Guided Fluorescence Intensity

“…Zinc oxide (ZnO) nanomaterials have been extensively utilized as key components in important technological devices such as optoelectronic modules [ 1 , 2 , 3 ], nanolasers [ 4 , 5 , 6 ], strain sensors [ 7 , 8 ], biosensors [ 9 , 10 , 11 , 12 , 13 ], and multi-emission waveguides [ 14 ]. In particular, ZnO nanorods (NRs) have drawn considerable attention in the broad fields of photonics, biosensing, and light detection due to their exceptional optical properties that stem from the NRs’ reduced dimensionality and high shape anisotropy [ 4 , 7 , 9 , 14 , 15 ].…”

Low Threshold and Long‐Range Propagation Plasmonic Nanolaser Enhanced by Black Phosphorus Nanosheets

“…also experimentally confirmed that a ZnO‐WO 3 ‐Al nanolaser structure has a lower nanolaser threshold than that of ZnO‐Al 2 O 3 ‐Al nanolaser structure. [ 17 ] However, it is worth noting that these SPPs waveguides usually have a large Ohmic loss and short transmission distance, due to the negative dielectric constant of metallic material. There is a trade‐off relationship between the transmission loss and optical field constraint in the SPPs nanolaser structure because of the Ohmic loss in metal substrate.…”