Model based prediction of nanostructured thin film morphology in an aerosol chemical vapor deposition process

Abstract

The aerosol chemical vapor deposition (ACVD) process has been demonstrated as a promising approach to the single step synthesis of nanostructured metal oxide thin films. Multiple process parameters control the nanostructure morphology and the growth of thin films. This work focuses on utilizing a simulation based approach to understand the role of these parameters in governing the morphology of the thin film. A finite element based computational fluid dynamics model, coupled with a discrete-sectional aerosol model, and a boundary layer diffusion and sintering model has been formulated to predict the evolution of particle size distribution and the morphology of the synthesized nanostructured film. The morphology predicted by the model was validated by experimental observations. The model enables scale up and wider application of the ACVD process and can be extended to other gas phase deposition systems.

Comparison of discrete, discrete-sectional, modal and moment models for aerosol dynamics simulations

“…In this case, the gas velocity and temperature are coupled with the aerosol dynamic models. The discrete and discrete-sectional models are verified in the work of Biswas et al (1997), Chadha et al (2017), and Gao et al (2017). The moment and modal models are verified in the work of Sharma, Wang, et al (2019) and Zhang et al (2018), and Wang et al (2017), respectively.…”

“…In this section, first different mathematical approaches to solving the general dynamics equation are illustrated. This is followed by the description of different Geng, Park, and Sajo 2013;Harrington and Kreidenweis 1998;Kommu, Khomami, and Biswas 2004;Pirjola et al 1999;Seigneur et al 1986;Talukdar and Swihart 2004;Tsantilis, Kammler, and Pratsinis 2002;Zhang et al 1999) Discrete model PSD is divided into discrete sizes and the increment volume of the two neighboring discrete sizes is the volume of the monomer Most accurate; Computationally expensive (Frenklach and Harris 1987;Friedlander 2000;Gelbard and Seinfeld 1979;Landgrebe and Pratsinis 1989;Lehtinen and Kulmala 2003;Smith, Wells, and (Frenklach and Harris 1987;Harrington and Kreidenweis 1998;Lin, Sethi, and Biswas 1992;McGraw 1997;Pirjola et al 1999;Pratsinis 1988;Seigneur et al 1986;Suh, Zachariah, and Girshick 2001;Talukdar and Swihart 2004;Williams 1986;Yamamoto 2014;Zhang et al 1999Zhang et al , 2018 (Biswas et al 1997;Chadha et al 2017;Gao et al 2017;Kommu et al 2004;Landgrebe and Pratsinis 1990;Moniruzzaman and Park 2006;Wu and Biswas 1998;Wu and Flagan 1988) Modal model Assume monodisperse for each mode; 2n...…”

“…Aerosol dynamic models (ADMs) permit the interaction of complex physical processes through simulation, and can be used to understand the experimental observations in aerosol systems. Panda and Pratsinis (1995) and Chadha et al (2017) used ADM to predict the properties of particles formed via vapor phase synthesis processes and based their recommendations for industrial scale up of the synthesis process on these predictions. Biswas et al (1997), Gao et al (2017), and Sharma, Dhawan, et al (2019) used ADM to predict the evolution of aerosol size distribution, in order to understand the underlying physics of particle formation by gas or solid combustion.…”

Mini Review on Gas-Phase Synthesis for Energy Nanomaterials

“…The route of particle formation for the different precursor feed conditions was simulated. Later, the discrete-model was successfully applied in modeling an ACVD reactor to simulate the particle formation and deposition. , In addition, Gao et al (2017) used this model to simulate the ultrafine particle formation in a high sodium lignite combustion reactor. Further, Dhamale et al (2018) coupled the discrete-section model with CFD to study the nucleation and growth of Y 2 O 3 nanoparticles in a thermal plasma reactor.…”

Nanostructured titanium dioxide coatings prepared by Aerosol Assisted Chemical Vapour Deposition (AACVD)

“…CVD deposition is a quite complex process, in which many different parameters can affect the characteristics of the coatings; considering in particular AACVD, the presence of a solvent and the aerosol dynamics are additional parameters to be considered [35]. Surely the nature of the precursor can play a crucial role in determining the morphology, the phase formed and the most suitable deposition temperature [16,20,21]; indeed, according to the molecular structure of the precursor and its stability, different growth mechanisms may occur.…”