Vapor-Phase Synthesis and Surface Passivation of ZnSe Nanocrystals
Vapor-Phase Synthesis and Surface Passivation of ZnSe Nanocrystals
复制标题
DOI：
10.1007/s11051-005-9023-z
复制
发表时间：
2006-06
影响因子：
2.5
通讯作者：
C. Sarigiannidis;Maria Koutsona;Maria Koutsona;A. Petrou;T. J. Mountziaris
中科院分区：
文献类型：
--
作者：
C. Sarigiannidis;Maria Koutsona;Maria Koutsona;A. Petrou;T. J. Mountziaris
II-VI纳米晶体（量子点）的气相合成与传统的液相技术相比具有几个优点，包括与微电子工业中现有操作的更好兼容性。另一方面，它使尺寸控制和表面钝化成为更具挑战性的任务。本文报道了在300 K和低压（120- 60 Torr）条件下，用二甲基锌：三乙胺（DMZ-TEA）加合物蒸气和硒化氢气体（均稀释在氢气中）在逆流喷射反应器中反应合成和表面钝化发光ZnSe纳米晶。两种反应物从垂直逆流结构的单独入口流入圆柱形腔室。ZnSe的均匀成核通过前体之间的不可逆反应发生。核随后通过表面反应和簇-簇聚结生长以形成表现出尺寸依赖性发光的纳米晶体。通过向反应器中引入1-戊乙烷的蒸气来实现表面钝化。硫醇蒸气不干扰初级纳米晶体的成核和生长，但显著改变在透射电子显微镜（TEM）网格上收集的最终凝结颗粒的形态和尺寸。硫醇蒸气在纳米晶体表面上的化学吸附也导致1个月后光致发光（PL）强度的较小降解。使用HR-TEM，化学计量分析，电子衍射和俄歇电子能谱（AES）的颗粒的结构和形态进行表征，而PL和拉曼光谱被用来研究其尺寸依赖的光学性质。
The vapor-phase synthesis of II–VI nanocrystals (quantum dots) has several advantages over traditional liquid-phase techniques, including better compatibility with existing operations in the microelectronics industry. On the other hand, it makes size control and surface passivation a more challenging task. In this paper we report the synthesis and surface passivation of luminescent ZnSe nanocrystals by reacting vapors of dimethylzinc:triethylamine (DMZ–TEA) adduct with hydrogen selenide gas (both diluted in hydrogen) in a counterflow jet reactor operating at 300 K and low pressures (120--60 Torr). The two reactants flow into a cylindrical chamber from separate inlets of a vertical opposed-flow configuration. Homogeneous nucleation of ZnSe occurs through an irreversible reaction between the precursors. The nuclei subsequently grow by surface reactions and cluster--luster coalescence to form nanocrystals that exhibit size-dependent luminescence. Surface passivation was achieved by introducing vapors of 1-pentanethiol into the reactor. The thiol vapors do not interfere with the nucleation and growth of the primary nanocrystals, but significantly change the morphology and size of the final coagulated particles collected on transmission electron microscopy (TEM) grids. The chemisorption of thiol vapors on the surface of the nanocrystals also leads to smaller degradation of the photoluminescence (PL) intensity after 1 month. Structural and morphological characterization of the particles was performed using HR-TEM, stoichiometric analysis using electron diffraction and Auger electron spectroscopy (AES), while PL and Raman spectroscopy were used to study their size-dependent optical properties.