Understanding the isothermal growth kinetics of cdse quantum dots through microfluidic reactor assisted combinatorial synthesis

What is it about?

Using microfluidic-assisted combinatorial reactor, the synthesis of CdSe quantum dots has been optimized through varying one parameter at a time and the isothermal growth kinetics of CdSe quantum dots using various models have been analyzed. To understand precisely the nucleation and growth characteristics of CdSe quantum dots (QDs), the CdSe QDs were synthesized at various experimental. Different model equations, like; acceleratory growth-time curves, sigmoidal growth-time curves or Johnson-Mehl-Avrami-Kolmogorov (JMAK), acceleratory growth-time curves based on diffusion, geometric model growth-time curve, and nth order growth-time curves were fitted. Among all growth model, JMAK model α=1-e^(-(〖kt)〗^n ),n=1 was the best fitted model using MATLAB interactive curve fitting procedure. Errors associated with the best fitted model and statistics for the goodness of fit were analyzed. Most of the models were negated other than the proposed model. The errors associated with proposed model are minimal, the growth kinetics and other associated statistical factors are very similar, for all the variables investigated. Minimal error associated with modelling, reproducibility and very similar data for growth kinetics for all studied parameters indicates the microfluidic assisted combinatorial synthesis can be used industrial production of QDs. From the proposed model through understanding of growth the QDs size and properties can be managed and simulated.

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Why is it important?

The nucleation and growth characteristics of CdSe QDs follow the JMAK growth model those were synthesized at various conditions like; varying precursor concentration, varying the molar ratio of the precursor at constant and variable concentration. Various models like; acceleratory growth-time curves, sigmoidal growth-time curves, acceleratory growth-time curves based on diffusion, geometric model growth-time curve, and nth order growth-time curves were fitted to the obtained data[20]. Among all growth model, JMAKs’ one-dimensional growth model α=1-e^(-(〖kt)〗^n ),n=1 was the best fitted model. Goodness of fit through MATLAB analysis resulted minimal errors, SSE, SE and RMSEs, indicated the proposed model hold good, accurate and free from random errors. Through our thorough investigation varying all possible parameters, reproducibility of the microfluidic assisted combinatorial synthesis has been well established. More importantly, kinetics, errors and other statistical factors are associated with the model is very similar or almost the same. Hence, the microfluidic assisted combinatorial synthesis can be used industrial production of QDs and from the proposed model through understanding of growth the QDs size and properties can be managed and simulated.

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