On the kinetics of the removal of ligands from films of colloidal nanocrystals by plasmas.
On the kinetics of the removal of ligands from films of colloidal nanocrystals by plasmas.
复制标题
关于等离子体从胶体纳米晶体薄膜中去除配体的动力学。
DOI：
--
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
L. Cademartiri
中科院分区：
文献类型：
--
作者：
Santosh Shaw;T. F. Silva;P. Mohapatra;Deyny L Mendivelso;Xinchun Tian;F. Naab;C. L. Rodrigues;Emily A. Smith;L. Cademartiri
本文描述了等离子体处理从胶体纳米组装体（CNA）中蚀刻配体的动力学限制。我们测量了CNA模型系统（球形ZrO 2纳米晶体，2.5-3.5 nm直径，用三辛基氧化膦封端）与电感耦合等离子体（He和O2进料气体，功率范围为7至30 W，压力范围为100至2000 mTorr，暴露时间范围为6至168 h）的配体的蚀刻动力学。在蚀刻的第一分钟，蚀刻速率减慢约一个数量级，之后，碳去除速率与CNA中碳浓度的三次方成比例。等离子体室中的压力振荡显着加速了总蚀刻速率。这些结果表明，蚀刻速率主要受两个主要因素影响：（i）在等离子体暴露的第一阶段中配体的交联，和（ii）在CNA表面处形成边界层。等离子体处理的优化条件允许蚀刻速率与先前的现有技术相比提高60倍，并且使等离子体处理的时间范围与煅烧的时间范围相当。
This paper describes the kinetic limitations of etching ligands from colloidal nanocrystal assemblies (CNAs) by plasma processing. We measured the etching kinetics of ligands from a CNA model system (spherical ZrO2 nanocrystals, 2.5-3.5 nm diameter, capped with trioctylphosphine oxide) with inductively coupled plasmas (He and O2 feed gases, powers ranging from 7 to 30 W, at pressures ranging from 100 to 2000 mTorr and exposure times ranging between 6 and 168 h). The etching rate slows down by about one order of magnitude in the first minutes of etching, after which the rate of carbon removal becomes proportional to the third power of the carbon concentration in the CNA. Pressure oscillations in the plasma chamber significantly accelerate the overall rate of etching. These results indicate that the rate of etching is mostly affected by two main factors: (i) the crosslinking of the ligands in the first stage of plasma exposure, and (ii) the formation of a boundary layer at the surface of the CNA. Optimized conditions of plasma processing allow for a 60-fold improvement in etching rates compared to the previous state of the art and make the timeframes of plasma processing comparable to those of calcination.