Ecole Normale Supérieure, CNRS-ENS-UPMC UMR 8640, Paris, France.
Nanotechnology. 2011 Jun 17;22(24):245601. doi: 10.1088/0957-4484/22/24/245601. Epub 2011 Apr 20.
Seedless hydrothermal synthesis has been improved by introducing an adequate content of ammonia into the nutrient solution, allowing the fabrication of dense and ultralong ZnO nanowire arrays over large areas on a substrate. The presence of ammonia in the nutrient solution facilitates the high density nucleation of ZnO on the substrate which is critical for the nanowire growth. In order to achieve an optimal growth, the growth conditions have been studied systematically as a function of ammonia content, growth temperature and incubation time. The effect of polyethyleneimine (PEI) has also been studied but shown to be of no benefit to the nucleation of ZnO. Ultradense and ultralong ZnO nanowires could be obtained under optimal growth conditions, showing no fused structure at the foot of the nanowire arrays. Due to different reaction kinetics, four growth regimes could be attributed, including the first fast growth, equilibrium phase, second fast growth and final erosion. Combining this simple method with optical lithography, ZnO nanowires could be grown selectively on patterned areas. In addition, the as-grown ZnO nanowires could be used for the fabrication of a piezoelectric nanogenerator. Compared to the device of ZnO nanowires made by other methods, a more than twice voltage output has been obtained, thereby proving an improved performance of our growth method.
无籽水热合成通过在营养溶液中引入适量的氨得到了改进，使得在基底上大面积制造致密的超长 ZnO 纳米线阵列成为可能。营养溶液中氨的存在促进了 ZnO 在基底上的高密度成核，这对于纳米线的生长至关重要。为了实现最佳生长，已经系统地研究了生长条件作为氨含量、生长温度和孵化时间的函数。还研究了聚乙烯亚胺（PEI）的影响，但结果表明它对 ZnO 的成核没有好处。在最佳生长条件下可以获得超密和超长的 ZnO 纳米线，纳米线阵列的底部没有融合结构。由于不同的反应动力学，可以归因于四个生长阶段，包括第一快速生长、平衡相、第二快速生长和最终侵蚀。将这种简单的方法与光刻相结合，可以选择性地在图案化区域上生长 ZnO 纳米线。此外，所生长的 ZnO 纳米线可用于制造压电纳米发电机。与其他方法制造的 ZnO 纳米线器件相比，已经获得了超过两倍的电压输出，从而证明了我们的生长方法的改进性能。
