Nonequilibrium hot-electron-induced wavelength-tunable incandescent-type light sources

Abstract

The collective oscillation of electrons located in the conduction band of metal nanostructures being still energized, with the energy up to the bulk plasmon frequency, are called nonequilibrium hot electrons. It can lead to the state-filling effect in the energy band of the neighboring semiconductor. Here, we report on the incandescent-type light source composed of Au nanorods decorated with single Ga-doped ZnO microwire (AuNRs@ZnO:Ga MW). Benefiting from Au nanorods with controlled aspect ratio, wavelength-tunable incandescent-type lighting was achieved, with the dominating emission peaks tuning from visible to near-infrared spectral regions. The intrinsic mechanism was found that tunable nonequilibrium distribution of hot electrons in ZnO:Ga MW, injected from Au nanorods, can be responsible for the tuning emission features. Apart from the modification over the composition, bandgap engineering, doping level, etc., the realization of electrically driving the generation and injection of nonequilibrium hot electrons from single ZnO:Ga MW with Au nanostructure coating may provide a promising platform to construct electronics and optoelectronics devices, such as electric spasers and hot-carrier-induced tunneling diodes.

Hybrid quadrupole plasmon induced spectrally pure ultraviolet emission from a single AgNPs@ZnO:Ga microwire based heterojunction diode

“…Thus, the PL emission enhancement of a single ZnO:Ga MW with Ag nanoparticle decoration cannot be attributed to resonant coupling between ZnO:Ga excitons and AgNPs plasmons at the interface. 21,22,55 When the output radiation from the heterojunction LED is absorbed by the deposited Ag nanoparticles, hybrid quadrupole plasmons can be excited. Aer excitation, nonradiative decay can occur through intraband excitations within the conduction band or through interband excitations, leading to transitions between the conduction band and other bands.…”

Enhanced luminescence/photodetecting bifunctional devices based on ZnO:Ga microwire/p-Si heterojunction by incorporating Ag nanowires

“…As we previously literature reported, individual ZnO:Ga MWs were synthesized with the vapor transport deposition method. 22,38 High-purity powders of ZnO, Ga 2 O 3 and graphite (C) with the weight ratio of 9:1:10 serving as the precursors, was placed in a corundum boat (the size of 20 cm (length) × 2 cm (width) × 1.5 cm (depth)). A cleaned Si crystal wafer (without any catalyst coating, and the size of 2 cm (length) × 2 cm (width)) was placed on the top of the mixture to collect the products.…”

“…As previously reported, the as-grown ZnO:Ga wires with straight sidewalls, hexagonal cross-section and good crystallinity have been successfully fabricated through one-step vapor transport deposition method. 22,38 The optical picture of the synthesized samples is exhibited in Fig. 1(a).…”

“…2(a), the blue solid line). 24,38,46 As we mentioned above, heterojunction composed of p-Si crystal wafer and an individual ZnO:Ga wire has been built up, incorporating Ni/Au and In working as electrodes for the carriers injection. Electrical characterization of as-fabricated heterojunction devices was tested.…”

“…In the simulation, the complex relative permittivity of the AgNWs upon 370 nm light irradiation was modeled by experimental dielectric data, the refractive index of ZnO:Ga was donated as 2.35, the refractive index of the air was 1.0, and the resonant wavelength was 370 nm. 7,38,45 A three-dimensional model composed of a AgNW with the diameter of about 35 nm placed on ZnO:Ga MW was constructed. First, the spatial distributions of electromagnetic field |E| 2 -intensity of a pentagonshaped AgNW at x-y-plane was implemented.…”