Zhang L, Heng C L, Wang X, Su W Y, Finstad T G
Opt Express. 2022 Oct 10;30(21):38167-38177. doi: 10.1364/OE.472497.
We studied the enhancement effects of ultraviolet (UV) emission from rare earth ytterbium (Yb) doped ZnO films, by using capping layers of Al and SiO micro-spheres. The films were deposited on Si substrates with magnetron sputtering followed by high temperature (∼1000°C) heat treatment, and then capped with a nanoscale ultrathin aluminum (Al) layer and/or SiO micro-spheres on the surface of the films. The photoluminescence (PL) results indicate that compared to the case without any capping, the UV emission is enhanced by a factor ranging from several to dozens times, the films capped with 2.0 nm Al layer and 5.0 µm SiO microspheres have the longest highest PL intensity among the samples. The PL enhancements are discussed in terms of increased optical (or electrical) fields around the surface of the films combined with defect passivation after the capping. Our work has proposed a strategy to enhance the UV emissions of ZnO, which will broaden the application potential of ZnO in UV photonics.
我们通过使用铝（Al）和二氧化硅（SiO）微球作为盖帽层，研究了稀土镱（Yb）掺杂的氧化锌（ZnO）薄膜的紫外（UV）发射增强效应。这些薄膜通过磁控溅射沉积在硅（Si）衬底上，随后进行高温（约1000°C）热处理，然后在薄膜表面覆盖一层纳米级超薄铝（Al）层和/或SiO微球。光致发光（PL）结果表明，与未进行任何盖帽处理的情况相比，UV发射增强了几倍到几十倍，在样品中，覆盖有2.0纳米Al层和5.0微米SiO微球的薄膜具有最长的最高PL强度。结合盖帽后薄膜表面周围光学（或电学）场的增加以及缺陷钝化来讨论PL增强效应。我们的工作提出了一种增强ZnO紫外发射的策略，这将拓宽ZnO在紫外光子学中的应用潜力。
