Division of Functional Materials, Korea Institute of Materials Science (KIMS), Changwon, Kyungnam, 641-010, Republic of Korea.
Nanotechnology. 2009 Dec 16;20(50):505603. doi: 10.1088/0957-4484/20/50/505603. Epub 2009 Nov 12.
We have investigated the effects of Pb2+ addition on the morphological development of CdSe nanocrystals. We show that the addition of Pb ions in the initial precursor solution changed the morphology of CdSe nanocrystals to branched rods with high aspect ratio. The branched nanocrystals are mainly composed of wurzite phase grown along the [001] direction and the length of rods in each branched nanocrystal can be increased by increasing the amount of Pb2+ addition to accelerate the anisotropic growth of the nanocrystals. The luminescence, however, mostly arises from trap-related recombination and is significantly red-shifted by Pb2+ addition. Surface passivations of the branched nanocrystals with ZnS were proved to be effective in eliminating trap emission and enhancing band-edge emission, leading to a larger quantum yield.
我们研究了 Pb2+ 添加对 CdSe 纳米晶体形态发育的影响。我们表明，在初始前体溶液中添加 Pb 离子改变了 CdSe 纳米晶体的形态，使其变为具有高纵横比的支化棒。支化纳米晶体主要由沿[001]方向生长的纤锌矿相组成，通过增加 Pb2+ 的添加量，可以加速纳米晶体的各向异性生长，从而增加每个支化纳米晶体中棒的长度。然而，发光主要源于与陷阱有关的复合，并且通过添加 Pb2+ 显著红移。用 ZnS 对支化纳米晶体进行表面钝化被证明可以有效地消除陷阱发射并增强带边发射，从而提高量子产率。
