期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 134, 期 41, 页码 17046-17052出版社
AMER CHEMICAL SOC
DOI: 10.1021/ja302964e
关键词
-
资金
- NSF [NSF-CHE 0911080]
- Florida-Georgia Lewis Stokes Alliance for Minority Participation fellowship
- MacDiarmid Institute
- Foundation for Research, Science and Technology (FRST) [PROJ-13733-NMTS]
- FRST [CONT-20707-NMTS-IRL]
- Division Of Chemistry
- Direct For Mathematical & Physical Scien [0911080] Funding Source: National Science Foundation
A century ago Ostwald described the Rule of Stages after deducing that crystal formation must occur through a series of intermediate crystallographic phases prior to formation of the final thermodynamically stable structure. Direct evidence of the Rule of Stages is lacking, and the theory has not been implemented to allow isolation of a selected structural phase. Here we report the role of Ostwald's Rule of Stages in the growth of CdSe quantum dots (QDs) from molecular precursors in the presence of hexadec-ylamine. It is observed that, by controlling the rate of growth through the reaction stoichiometry and therefore the probability of ion-packing errors in the growing QD, the initially formed zinc blende (ZB) critical nuclei representing the kinetic phase can be maintained at sizes >14 nm in diameter without phase transformation to the thermodynamic wurtzite (WZ) structure. An intermediate pseudo-ZB structure is observed to appear at intermediate reaction conditions, as predicted by Ostwald. The ZB and pseudo-ZB structures convert to the WZ lattice above a critical melting temperature. This study validates Ostwald's Rule of Stages and provides a phase diagram for growth of CdSe QDs exhibiting a specific crystallographic motif
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据