Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.
ACS Nano. 2011 Feb 22;5(2):1291-6. doi: 10.1021/nn1029845. Epub 2011 Feb 1.
AlGaN ternary alloys have unique properties suitable for numerous applications due to their tunable direct band gap from 3.4 to 6.2 eV by changing the composition. Herein we report a convenient chemical vapor deposition growth of the quasi-aligned Al(x)Ga(1-x)N alloy nanocones over the entire composition range. The nanocones were grown on Si substrates in large area by the reactions between GaCl(3), AlCl(3) vapors, and NH(3) gas under moderate temperature around 700 °C. The as-prepared wurtzite Al(x)Ga(1-x)N nanocones have single-crystalline structure preferentially growing along the c-axis, with homogeneous composition distribution, as revealed by the characterizations of electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and selected area electron diffraction. The continuous composition tunability is also demonstrated by the progressive evolutions of the band edge emission in cathodoluminescence and the turn-on and threshold fields in field emission measurements. The successful preparation of Al(x)Ga(1-x)N nanocones provides the new possibility for the further development of advanced nano- and opto-electronic devices.
AlGaN 三元合金具有独特的性质，由于其组成可调的直接带隙从 3.4 到 6.2eV，因此适用于许多应用。在这里，我们报告了一种方便的化学气相沉积方法，可在整个组成范围内生长准对齐的 Al(x)Ga(1-x)N 合金纳米锥。纳米锥是通过 GaCl(3)、AlCl(3)蒸气和 NH(3)气体在 700°C 左右的中等温度下反应在 Si 衬底上大面积生长的。所制备的纤锌矿 Al(x)Ga(1-x)N 纳米锥具有单晶结构，优先沿 c 轴生长，成分分布均匀，这可通过电子显微镜、X 射线衍射、能谱和选区电子衍射的特性来证明。通过在阴极发光中带边发射的逐渐演变以及在场发射测量中的开启和阈值场，也证明了连续的组成可调性。Al(x)Ga(1-x)N 纳米锥的成功制备为进一步开发先进的纳米和光电子器件提供了新的可能性。
