Controlling Green-to-Blue Luminescence in Multidimensional ZnO Interfaces - Mechanistic Insights
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-08-16 |
| Journal | ACS Applied Optical Materials |
| Authors | AndrĂ©s GaldĂĄmezâMartĂnez, Erika Armenta-Jaime, P. G. Zayas-BazĂĄn, G. Santana, C. SĂĄnchez-AkĂ© |
| Institutions | University of Southern Denmark, Florida Polytechnic University |
| Citations | 15 |
Abstract
Section titled âAbstractâThis report presents a thorough study on controlling the morphological and optical properties of zinc oxide nanostructured coatings (n-ZnO) using the vapor-phase growth technique with metallic catalysts on silicon substrates. A successful control over the morphological characteristics of the n-ZnO materials, yielding a mixed one-dimensional (1D)-two-dimensional (2D) matrix through simultaneous competing vapor-liquid-solid (VLS) and vapor-solid-solid (VSS) growth mechanisms, was shown. The obtained 1DZnO nanostructured materials exhibited a diameter of 112 nm and a length of 3.7 ÎŒm (i.e., nanowires) along with 2DZnO nanomaterials with a surface area of 2.6 ÎŒm2 (i.e., nanowalls) in average. The investigation also emphasizes the influence of the Zn-gas precursor gradient on the structuresâ morphology, yielding a variation in the 2DZnO surface area from 11.8 to 0.5 ÎŒm2 as the distance between the evaporation source and the substrate increased from 27 to 324 mm. Furthermore, a defect engineering process involving thermal treatments in hydrogen, oxygen, and nitrogen atmospheres is used to tune the visible photoluminescence response of the material from a 526 to a 400 nm emission. This approach enables control over multiple recombination centers (i.e., oxygen and zinc interstitials and vacancies), modifying the optical properties of the n-ZnO. The study reveals a reversible, controllable, and reproducible transition between near-band-edge (NBE) and deep-level emission (DLE). As a perspective, laser ablation treatments were also used to modulate the photoluminescence and morphological properties. We found that n-ZnO visible emission was blue-shifted when irradiating with 5-21 mJ laser energy. The findings suggest that this capability holds exciting potential for developing advanced nanostructures on contemporary technologies, such as lighting and sensing, where the continuous search for an efficient and cost-effective blue emitter is necessary.