Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697-2700, United States.
ACS Appl Mater Interfaces. 2013 Aug 14;5(15):6808-14. doi: 10.1021/am401716u. Epub 2013 Jul 19.
The efficacy of laser annealing for the thermal annealing of nanocrystalline gold nanowires is evaluated. Continuous laser illumination at 532 nm, focused to a 0.5 μm diameter spot, was rastered perpendicular to the axis of nanocrystalline gold nanowire at ∼2 kHz. This rastered beam was then scanned down the nanowire at velocities from 7 to 112 nm/s. The influence on the electrical resistance of the gold nanowire of laser power, polarization, translation speed, and nanowire width were evaluated. Nanocrystalline gold nanowires were prepared on glass surfaces using the lithographically patterned nanowire electrodeposition (LPNE) method. These nanowires had a rectangular cross section with a height of 20 (± 3) nm and widths ranging from 76 to 274 nm. The 4-contact electrical resistance of the nanowire is measured in situ during laser annealing and a real-time decrease in electrical resistance of between 30 and 65% is observed, depending upon the laser power and scan rate along the nanowire. These resistance decreases are associated with an increase in the mean grain diameter within these nanowires, measured using transmission electron microscopy, of up to 300%. The observed decrease in the electrical resistance induced by laser annealing conforms to classical predictions based upon the reduction in grain boundary scattering induced by grain growth.
评估了激光退火对纳米晶金纳米线热退火的效果。在 532nm 波长下使用连续激光照射，聚焦到 0.5μm 的直径光斑，以约 2kHz 的频率垂直于纳米晶金纳米线的轴进行激光扫描。然后，以 7 到 112nm/s 的速度将扫描光束沿纳米线向下移动。评估了激光功率、偏振、平移速度和纳米线宽度对金纳米线电阻的影响。纳米晶金纳米线是使用光刻图案纳米线电沉积（LPNE）方法在玻璃表面上制备的。这些纳米线具有 20（±3）nm 的高度和 76 到 274nm 之间的宽度的矩形横截面。在激光退火过程中，纳米线的 4 点接触电阻进行原位测量，观察到电阻实时降低 30%到 65%，这取决于激光功率和沿纳米线的扫描速度。这些电阻降低与透射电子显微镜测量的这些纳米线中平均晶粒直径的增加有关，最大可达 300%。激光退火引起的电阻降低符合基于晶粒生长引起的晶界散射减少的经典预测。
