Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Nanotechnology. 2013 Feb 15;24(6):065601. doi: 10.1088/0957-4484/24/6/065601. Epub 2013 Jan 16.
The concept of band engineering dilute nitride semiconductors into nanowires is introduced. Using plasma-assisted molecular beam epitaxy, dilute nitride GaAsN/GaAs heterostructure nanowires are grown on silicon (111) substrates. Growth of the nanowires under high As overpressure results in a regular wire diameter of 350 nm with a length exceeding 3 μm. The GaAsN/GaAs nanowires show characteristics including favorable vertical alignment, hexagonal cross-sectional structure with {110} facets, regions of wurtzite and zinc-blende phases, and a core-shell-type heterostructure. The nanowires are composed of GaAsN shells containing up to 0.3% nitrogen surrounding GaAs cores. Panchromatic cathodoluminescence images show intensity modulation along the length of the nanowires that is possibly related to the interfaces of wurtzite/zinc-blende regions. Photoluminescence with peak wavelengths between 870 and 920 nm is clearly observed at room temperature. The spectral red shift depends on the amount of introduced nitrogen. These results reveal a method for precise lattice and band engineering of nanowires composed of dilute nitride semiconductors.
将能带工程概念引入到氮化物半导体纳米线中。采用等离子体辅助分子束外延法，在硅（111）衬底上生长了 GaAsN/GaAs 稀氮化物异质结构纳米线。在高砷过压下生长纳米线会导致其直径为 350nm，长度超过 3μm，且具有规则的线径。GaAsN/GaAs 纳米线具有以下特点：垂直排列良好、具有{110}面的六方横截面结构、存在纤锌矿和闪锌矿相区域以及核壳型异质结构。纳米线由 GaAsN 壳层组成，其包含高达 0.3%的氮，围绕 GaAs 芯层。全彩阴极荧光图像显示，纳米线的长度上存在强度调制，这可能与纤锌矿/闪锌矿区域的界面有关。在室温下，清晰地观察到峰值波长在 870nm 到 920nm 之间的光致发光。光谱的红移取决于引入的氮的量。这些结果表明了一种对由稀氮化物半导体组成的纳米线进行精确晶格和能带工程的方法。
