用纳米棒ZnO作模板生长无支撑的AlN纳米晶

用金属有机物气相外延在纳米棒ZnO模板上沉积AlN薄膜.SEM测试表明该薄膜形成了一种倾倒纳米棒的表面.而GIXRD测试进一步证实它是纤锌矿结构的AlN,晶粒尺度约为12nm,接近于ZnO纳米棒的直径(30nm).这意味着纳米棒结构的ZnO能限制AlN的横向生长.此外,高温下用H2刻蚀ZnO直接在生长中实现了外延层的剥离.最终得到了无支撑的AlN纳米晶,完整无破损的区域约为1cm×1cm.定义这个生长机制为"生长-刻蚀-合并"过程.

Growth of Free-Standing AlN Nanocrystals on Nanorod ZnO Template

AlN film is deposited on a nanorod ZnO template by metalorganic chemical vapor deposition. Scanning electron microscopy measurements reveal that this film forms a lying nanorod surface. The grazing incidence Xray diffraction further proves that it is entirely a wurtziteAlN structure, and the average size of the crystallite grains is about 12nm,which is near the ZnO nanorod diameter (30nm). This means that the nanorod ZnO template can restrict the AlN lateral overgrowth. Additionally, by etching the ZnO template with H2 at high temperatures,we directly achieve epitaxial lift-off during the growth process. Eventually,free-standing AlN nanocrystals are achieved,and the undamaged area is near 1cm × 1cm. We define the growth mechanism as a "grow-etchmerge" process.