Room-temperature intrinsic excitonic luminescence from a hexagonal boron nitride thin film grown on a sapphire substrate by low-pressure chemical vapor deposition using BCl3 as a boron source
Room-temperature intrinsic excitonic luminescence from a hexagonal boron nitride thin film grown on a sapphire substrate by low-pressure chemical vapor deposition using BCl3 as a boron source
复制标题
DOI：
10.35848/1347-4065/ac093f
复制
发表时间：
2021
影响因子：
1.5
通讯作者：
N. Umehara;Takuro Adachi;A. Masuda;T. Kouno;H. Kominami;K. Hara
中科院分区：
文献类型：
--
作者：
N. Umehara;Takuro Adachi;A. Masuda;T. Kouno;H. Kominami;K. Hara
以BCl3为硼源，在衬底温度为1200℃，反应器压力为5 kPa的条件下，采用化学气相沉积方法在C平面蓝宝石衬底上制备了六方氮化硼薄膜。薄膜由平顶柱状晶粒组成，在衬底上外延生长。该样品在室温下表现出明显的本征激子阴极发光（CL），虽然在350 nm左右的宽发射占主导地位。请注意，在带边缘区域的光谱形状在峰值波长和宽度方面与观察到的高质量体晶体密切匹配。表面的CL图像显示了薄膜结构与发光性能之间的相关性，其中仅从柱状晶粒中表现出本征激子发光，而杂质和/或缺陷相关的发射主要来自具有随机取向晶粒的表面缺陷。
A hexagonal boron nitride thin film was prepared on a c-plane sapphire substrate at a substrate temperature of 1200 °C and a reactor pressure of 5 kPa by chemical vapor deposition using BCl3 as a boron source. The film, consisting of columnar grains with flat top surfaces, grew epitaxially on the substrate. This sample showed pronounced intrinsic exciton cathodoluminescence (CL) at 215 nm at room temperature, although broad emission at around 350 nm was dominant. Note that the spectrum shape in the band edge region closely matched that observed for a high-quality bulk crystal in terms of peak wavelength and width. The CL images of the surface revealed the correlation between the film structure and the luminescence property, where the intrinsic excitonic luminescence was exhibited only from the columnar grains, whereas the impurity- and/or the defect-related emissions were observed mainly from surface defects with randomly oriented grains.