Skku Advanced Institute of Nanotechnology, School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746, Korea.
ACS Appl Mater Interfaces. 2012 Feb;4(2):805-10. doi: 10.1021/am201446u. Epub 2012 Jan 17.
Carbon-containing alloy materials such as Ge(1-x)C(x) are attractive candidates for replacing silicon (Si) in the semiconductor industry. The addition of carbon to diamond lattice not only allows control over the lattice dimensions, but also enhances the electrical properties by enabling variations in strain and compositions. However, extremely low carbon solubility in bulk germanium (Ge) and thermodynamically unfavorable Ge-C bond have hampered the production of crystalline Ge(1-x)C(x) alloy materials in an equilibrium growth system. Here we successfully synthesized high-quality Ge(1-x)C(x) alloy nanowires (NWs) by a nonequilibrium vapor-liquid-solid (VLS) method. The carbon incorporation was controlled by NW growth conditions and the position of carbon atoms in the Ge matrix (at substitutional or interstitial sites) was determined by the carbon concentration. Furthermore, the shrinking of lattice spacing caused by substitutional carbon offered the promising possibility of band gap engineering for photovoltaic and optoelectronic applications.
含碳合金材料，如 Ge(1-x)C(x)，是在半导体行业替代硅 (Si) 的有吸引力的候选材料。在金刚石晶格中添加碳不仅可以控制晶格尺寸，还可以通过应变和组成的变化来增强其电学性能。然而，在平衡生长系统中，碳在块状锗 (Ge) 中的极低溶解度和热力学上不利的 Ge-C 键阻碍了结晶 Ge(1-x)C(x) 合金材料的生产。在这里，我们通过非平衡汽-液-固（VLS）方法成功地合成了高质量的 Ge(1-x)C(x) 合金纳米线（NWs）。通过 NW 生长条件控制碳的掺入，碳原子在 Ge 基体中的位置（替位或间隙位置）由碳浓度决定。此外，替位碳引起的晶格间距收缩为光伏和光电子应用的能带隙工程提供了有前景的可能性。
