Broadband Omnidirectional Light Trapping in Gold-Decorated ZnO Nanopillar Arrays

Abstract

The photoluminescence (PL) and reflectivity characteristics of zinc oxide nanopillars (ZnO-NPs) grown on indium-tin-oxide (ITO)-coated glasses were investigated. The room temperature PL showed bright white-light emission for the undoped ZnO-NPs grown at 600 °C, suggesting the close relation between the optical characteristic and the growth conditions being carried out for obtaining the present ZnO-NPs. The reflectivity of the as-grown ZnO-NPs array was about ∼29% with the wavelength of the incident light ranging from 200 to 1800 nm. Nevertheless, the reflectance reduced significantly to less than 9.9% when a layer of gold (Au) was deposited on ZnO-NPs by sputtering for 5 min, corresponding to more than 65% reduction in Au-coated ZnO-NPs (Au/ZnO-NPs). Moreover, the angle-resolved reflectance measurements on the present Au/ZnO-NPs array show an omnidirectional light-trapping characteristic. These remarkable characteristics, broadband and omnidirectional light-trapping of Au/ZnO-NPs, are attributed to the extended effective optical path of the incident light due to subwavelength scattering resulting from the presence of Au nanoparticles.

Green Synthesis of Luminescent Gold-Zinc Oxide Nanocomposites: Cell Imaging and Visible Light–Induced Dye Degradation

“…Synthesis of metal-based nanocomposites by organic solvent-free conditions has drawn a lot of attention in the current decade (Li et al, 2013;Yao et al, 2013;Zhang et al, 2016;Qi et al, 2019;Ritchie et al, 2019). Au-ZnO nanocomposites, which are well known for a variety of applications, have been synthesized at high temperature in the presence of organic solvent (Yao et al, 2011;Tahir et al, 2013;Hang et al, 2016;Chang et al, 2017;Lupan et al, 2019). There are two reports, where AuNP was decorated on the crystalline ZnO nanorod surface at high temperature (Unlu et al, 2015;Ning et al, 2019).…”

Highly Sensitive UV Photodiode Composed of β-Polyfluorene/YZnO Nanorod Organic-Inorganic Hybrid Heterostructure

“…For the last two decades, ZnO nanostructures have garnered substantial attention because of their prodigious potential for blue and ultra-violet (UV) optoelectronic devices [1][2][3][4][5][6]. Among various nanostructures, 1-dimensional ZnO (e.g., nanorod [7,8], nanoneedle [9,10], nanopillar [11,12], etc.) is one of the most attractive nanoarchitectures due to its short pathway for carrier transport [13], high surface-to-volume ratio for photon collection [14], and low exciton-phonon coupling strength [15].…”

Cathodoluminescence study of defects in thermal treatment of zinc titanate thin films deposited by a cosputtering process

“…Lin et al have found that based on the composite of ZnO nanorods and TiO 2 , the band edge emission of ZnO nanorods can be enhanced up to 120 times . For optoelectronic devices, doped ZnO films have also been deposited . The properties of the ZnO–TiO 2 system that are responsible for the luminescence performance therefore becomes an interesting issue.…”