Colloidal Synthesis of PbS and PbS/CdS Nanosheets Using Acetate-Free Precursors
Colloidal Synthesis of PbS and PbS/CdS Nanosheets Using Acetate-Free Precursors
复制标题
DOI：
10.1021/acs.chemmater.5b03348
复制
发表时间：
2016-01-12
影响因子：
8.6
通讯作者：
Wise, Frank W.
中科院分区：
文献类型：
--
作者：
Zhang, Haitao;Savitzky, Benjamin H.;Wise, Frank W.
为胶体PbS纳米片的合成和表面改性提供了新的方法。我们发现残留的乙酸盐是现有合成方法中形成PbS纳米片的关键试剂。然而，反应混合物中醋酸酯的含量难以控制，这大大降低了合成的再现性。为了解决这个问题，我们开发了一种无醋酸盐的合成方法来生产横向尺寸为几百纳米的胶体PbS纳米片。通过改变合成参数，可以很容易地调整PbS纳米片的厚度和形状。合成的纳米片的光致发光量子产率约为6%。时间分辨光致发光光谱分析表明，载流子在纳米片中的衰变不是单指数的，而是涉及到表面缺陷状态和多个载流子相互作用。PbS纳米片表面可以通过与Cd（OA）的反应进行修饰(2)。原子分辨电镜显示PbS/CdS形成核壳纳米结构，PbS/CdS纳米片的光致发光量子产率达到11%左右。
New methods are developed for the synthesis and surface modification of colloidal PbS nanosheets. We find that residual acetate is a crucial reagent for the formation of PbS nanosheets by existing syntheses. The amount of acetate in reaction mixtures is, however, difficult to control, which substantially reduces the reproducibility of the synthesis. To solve this problem, we develop an acetate-free synthetic method to yield colloidal PbS nanosheets with lateral dimensions of several hundred nanometers. The thickness and shape of PbS nanosheets can be readily tuned by varying the synthetic parameters. Assynthesized nanosheets have a photoluminescence quantum yield of around 6%. Time-resolved photoluminescence spectroscopy shows that the carrier decay in nanosheets is not a single exponential but involves surface defect states as well as multiple carrier interactions. The surfaces of PbS nanosheets can be modified by reaction with Cd(OA)(2). Atomic resolution electron microscopy reveals the formation of PbS/CdS core/shell nanostructures, and the photoluminescence quantum yield of PbS/CdS nanosheets reaches about 11%.