ISOM and Dept. Ingeniería Electrónica, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, E-28040 Madrid, Spain.
Nanotechnology. 2017 Sep 8;28(36):365704. doi: 10.1088/1361-6528/aa78e6. Epub 2017 Jun 12.
Despite the strong interest in optoelectronic devices working in the deep ultraviolet range, no suitable low cost, large-area, high-quality AlN substrates have been available up to now. The aim of this work is the selective area growth of AlN nanocolumns by plasma assisted molecular beam epitaxy on polar (0001) and semi-polar (11-22) GaN/sapphire templates. The resulting AlN nanocolumns are vertically oriented with semi-polar {1-103} top facets when grown on (0001) GaN/sapphire, or oriented at 58° from the template normal and exposing {1-100} non-polar top facets when growing on (11-22) GaN/sapphire, in both cases reaching filling factors ≥80%. In these kinds of arrays each nanostructure could function as a building block for an individual nano-device or, due to the large filling factor values, the overall array top surfaces could be seen as a quasi (semi-polar or non-polar) AlN pseudo-template.
尽管人们对工作在深紫外范围的光电设备有着浓厚的兴趣，但迄今为止，还没有合适的低成本、大面积、高质量的 AlN 衬底。本工作的目的是通过等离子体辅助分子束外延在极性（0001）和半极性（11-22）GaN/蓝宝石模板上选择性地生长 AlN 纳米柱。在（0001）GaN/蓝宝石上生长时，所得的 AlN 纳米柱垂直取向，具有半极性{1-103}顶部晶面；在（11-22）GaN/蓝宝石上生长时，纳米柱以 58°偏离模板法线，暴露{1-100}非极性顶部晶面，在这两种情况下，填充因子均≥80%。在这种阵列中，每个纳米结构都可以作为单个纳米器件的构建块，或者由于填充因子值较大，整个阵列的顶部表面可以看作是准（半极性或非极性）AlN 伪模板。
