Physicochemical Processes And Mathematical Modeling Of Ⅳ-Ⅵ Quantum Dots Synthesis By Hot-injection Method

Quantum dots(QDs),also known as semiconductor nanocrystals,are a type of new optoelectronic materials.Because their adjustable band gap,QDs can be made into thin films at low temperature,which are the core materials of solar buildings in the future.The key to realize the commercial development of green building in the future is to control the size,size distribution and output of quantum dots to obtain the synthetic strategies of quantum dot materials for mass production of high quality customized optoelectronic properties.By Hot-Injection solution synthesizing QDs,batch-to-batch preparation and low expected cost,although many experiments and theoretical studies have been carried out to synthesize colloidal quantum dots(CQDs),due to the rapid reaction rate of the whole system.Little is known about the size characteristics and yield formation mechanism of CQDs at different growth stages.The main purpose of this work is to study the physicochemical processes of Hot-Injection synthesis of Ⅳ-Ⅵ colloidal quantum dots(Ⅳ-Ⅵ CQDs),explore the nucleation conditions and growth process of quantum dots,and take the classical thermal injection synthesis of lead sulfide(PbS),lead selenide(PbSe)CQDs as examples to construct the corresponding mathematical modeling,combing the influencing factors and influencing laws.The main tasks include:1.The formation process of Ⅳ-Ⅵ CQDs.The basic synthesis method of quantum dots and the classical nucleation and growth model of semiconductor nanocrystals are combed,and the improved kinetic model is established.The numerical analysis results are compared and verified with the existing literature data.2.Nucleation and growth of PbS CQDs at variable solution temperatures.A mathematical model of the physicochemical process for the synthesis of lead sulfide CQDs by Hot-Injection under variable temperature conditions is presented.The impacts of these influence factors on the nucleation conditions and growth processes of PbS QDs are analyzed through combining the operating procedures of reaction system,the reactants ratio,the structural characteristics of the reacting nanoparticles and the heat transfer parameters of the flask.3.Numerical analytical study of nucleation conditions and growth rate equations for Ⅳ-Ⅵ CQDs.the MATLAB realization Fokker-Planck the nucleation and growth of CQDs is obtained by solving the equation of variable coefficients.The above work can provide a reasonable strategy for the design of automatic synthesis of colloidal quantum dots and help the practice of large-scale automatic synthesis of customized physicochemical characteristics of quantum dots.