Kinetics of II-VI and III-V Colloidal Semiconductor Nanocrystal Growth:  “Focusing” of Size Distributions

1998 ◽  
Vol 120 (21) ◽  
pp. 5343-5344 ◽  
Author(s):  
Xiaogang Peng ◽  
J. Wickham ◽  
A. P. Alivisatos
Keyword(s):  
Size Distributions ◽  
Semiconductor Nanocrystal ◽  
Nanocrystal Growth ◽  
Colloidal Semiconductor ◽  
Kinetics Of

Chemical Availability of Bromide Dictates CsPbBr3 Nanocrystal Growth

2019 ◽  
Author(s):  
Je-Ruei Wen ◽  
Benjamin Roman ◽  
Freddy Rodriguez Ortiz ◽  
Noel Mireles Villegas ◽  
Nicholas Porcellino ◽  
...  
Keyword(s):  
Reaction Time ◽  
Growth Mechanism ◽  
Chemical Control ◽  
Critical Role ◽  
Phase Evolution ◽  
Detailed Understanding ◽  
Semiconductor Nanocrystal ◽  
Nanocrystal Growth ◽  
Chemical Availability

Lack of detailed understanding of the growth mechanism of CsPbBr3 nanocrystals has hindered sophisticated morphological and chemical control of this important emerging optoelectronic material. Here, we have elucidated the growth mechanism by slowing the reaction kinetics. When 1-bromohexane is used as an alternative halide source, bromide is slowly released into the reaction mixture, extending the reaction time from ~3 seconds to greater than 20 minutes. This enables us to monitor the phase evolution of products over the course of reaction, revealing that CsBr is the initial species formed, followed by Cs4PbBr6, and finally CsPbBr3. Further, formation of monodisperse CsBr nanocrystals is demonstrated in a bromide-deficient and lead-abundant solution. The CsBr can only be transformed into CsPbBr3 nanocubes if additional bromide is added. Our results indicate a fundamentally different growth mechanism for CsPbBr3 in comparison with more established semiconductor nanocrystal systems and reveal the critical role of the chemical availability of bromide for the growth reactions.<br>

scholarly journals Automated System for Kinetic Analysis of Particle Size Distributions for Pharmaceutically Relevant Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
John-Bruce D. Green ◽  
Phillip W. Carter ◽  
Yingqing Zhang ◽  
Dipa Patel ◽  
Priyanka Kotha ◽  
...  
Keyword(s):  
Particle Size ◽  
Clinical Importance ◽  
Automated System ◽  
Size Distributions ◽  
Mixing Conditions ◽  
Particle Size Distributions ◽  
Complex Formulation ◽  
Wide Range ◽  
Key Variables ◽  
Kinetics Of

Detailing the kinetics of particle formation for pharmaceutically relevant solutions is challenging, especially when considering the combination of formulations, containers, and timescales of clinical importance. This paper describes a method for using commercial software Automate with a stream-selector valve capable of sampling container solutions from within an environmental chamber. The tool was built to monitor changes in particle size distributions via instrumental particle counters but can be adapted to other solution-based sensors. The tool and methodology were demonstrated to be highly effective for measuring dynamic changes in emulsion globule distributions as a function of storage and mixing conditions important for parenteral nutrition. Higher levels of agitation induced the fastest growth of large globules (≥5 μm) while the gentler conditions actually showed a decrease in the number of these large globules. The same methodology recorded calcium phosphate precipitation kinetics as a function of [Ca2+] and pH. This automated system is readily adaptable to a wide range of pharmaceutically relevant systems where the particle size is expected to vary with time. This instrumentation can dramatically reduce the time and resources needed to probe complex formulation issues while providing new insights for monitoring the kinetics as a function of key variables.

Dissolution kinetics of colemanite in HCl solutions by measuring particle size distributions

2017 ◽  
Vol 53 (1) ◽  
pp. 198-205 ◽  
Author(s):  
Hikmet Sis ◽  
Ismail Bentli ◽  
Nizamettin Demirkiran ◽  
Ahmet Ekmekyapar
Keyword(s):  
Particle Size ◽  
Dissolution Kinetics ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Kinetics Of

Kinetics of formation of fibrin oligomers. II. Size distributions of ligated oligomers

Biopolymers ◽  
1982 ◽  
Vol 21 (11) ◽  
pp. 2265-2277 ◽  
Author(s):  
Marsha D. Bale ◽  
Paul A. Janmey ◽  
John D. Ferry
Keyword(s):  
Size Distributions ◽  
Kinetics Of Formation ◽  
Kinetics Of

Manipulation of semiconductor nanocrystal growth in polymer soft solids

Soft Matter ◽  
2009 ◽  
Vol 5 (21) ◽  
pp. 4113 ◽  
Author(s):  
Hao Zhang ◽  
Yue Tang ◽  
Junhu Zhang ◽  
Minjie Li ◽  
Xi Yao ◽  
...  
Keyword(s):  
Semiconductor Nanocrystal ◽  
Soft Solids ◽  
Nanocrystal Growth

scholarly journals Coherent Acoustic Phonons in Colloidal Semiconductor Nanocrystal Superlattices

ACS Nano ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 1163-1169 ◽  
Author(s):  
Caroline L. Poyser ◽  
Thomas Czerniuk ◽  
Andrey Akimov ◽  
Benjamin T. Diroll ◽  
E. Ashley Gaulding ◽  
...  
Keyword(s):  
Acoustic Phonons ◽  
Semiconductor Nanocrystal ◽  
Nanocrystal Superlattices ◽  
Colloidal Semiconductor ◽  
Coherent Acoustic Phonons

Competitive diffusion-controlled growth of porphyroblasts

1991 ◽  
Vol 55 (380) ◽  
pp. 317-330 ◽  
Author(s):  
William D. Carlson
Keyword(s):  
Crystal Size ◽  
Quantitative Information ◽  
Chemical Inhomogeneity ◽  
Controlled Growth ◽  
Size Distributions ◽  
Compositional Zoning ◽  
Frequency Distributions ◽  
Diffusion Controlled ◽  
Intergranular Diffusion ◽  
Kinetics Of

AbstractIn a diffusion-controlled process of nucleation and growth, adjacent porphyroblasts compete with one another for nutrients. When the effects of this competition are evaluated quantitatively for garnet porphyroblasts in pelitic rocks from the Picuris Range of New Mexico (U.S.A.), significant correlations arise between crystal sizes and the volumes of the domains from which the crystals drew their nutrients. These correlations strengthen the conclusion drawn from earlier work on spatial dispositions, zoning patterns, and crystal size distributions that the kinetics of intergranular diffusion governed the crystallisation of these porphyroblasts.Computer simulations indicate that competition for nutrients during diffusion-controlled growth may have small but detectable effects on crystal size frequency distributions. Diffusional competition therefore introduces relatively minor inaccuracies into attempts to extract quantitative information on crystallisation processes from size distributions using models for the growth of isolated porphyroblasts. In contrast, the effects of diffusional competition on patterns of compositional zoning may be substantial, especially for porphyroblasts in rocks for which chemical inhomogeneity of the precursor leads to strongly clustered spatial dispositions. In such rocks, clustering may alter the patterns of compositional zoning in ways that obscure evidence for diffusion-controlled growth.

scholarly journals Temperature-Dependent Emission Kinetics of Colloidal Semiconductor Nanoplatelets Strongly Modified by Stacking

2016 ◽  
Vol 7 (3) ◽  
pp. 548-554 ◽  
Author(s):  
Onur Erdem ◽  
Murat Olutas ◽  
Burak Guzelturk ◽  
Yusuf Kelestemur ◽  
Hilmi Volkan Demir
Keyword(s):  
Temperature Dependent ◽  
Colloidal Semiconductor ◽  
Kinetics Of
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