AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Controlled Morphology of Nanostructured Metal Oxide Films for ACVD and FLAR Methodologies
KELSEY HADDAD, Tandeep Chadha, Pratim Biswas, Nalin Katta, Barani Raman, Washington University in St.Louis
Abstract Number: 521 Working Group: Nanoparticles and Materials Synthesis
Abstract Nanostructured film synthesis has attracted enormous interest for both fundamental research as well as technical applications. These applications span a number of industrial sectors, including corrosion protection, pollutant decomposition, and solar energy storage and transformation. The morphology of these thin films plays an integral role in their performance and should be tailored for the specific application of interest. Aerosol chemical vapor deposition (ACVD) and flame aerosol reactors (FLAR) are two single-step aerosol methodologies commonly employed for the deposition of thin films. Three typical film morphologies—dense, columnar, and granular—are observed in both systems. While the aerosol phase dynamics are highly complex, the different morphologies can be reduced to three major deposition regimes: vapor-dominant regime, vapor-particle mixed regime, and particle-dominant regime[1]. The deposition regime is controlled by the relationship between four characteristic times, including residence time (τres), reaction time of the precursor (τrxn), sintering time (τsin), and particle-particle collision time (τcoll)[2]. Through the analysis of experiments conducted on TiO2 thin film deposition, using titanium tetraisopropoxide (TTIP), a morphology map of thin film deposition as a function of the characteristic times was created. The consolidation of these characteristic times to form a morphology diagram allows for the efficient control of thin film morphology across the broad spectrum of input parameters and even precursors. The results were then used to aid in the optimization of nanostructured SnO2 films through ACVD for applications in room-temperature gas sensing.
1. An, W.-J., E. Thimsen, and P. Biswas, Aerosol-chemical vapor deposition method for synthesis of nanostructured metal oxide thin films with controlled morphology. The Journal of Physical Chemistry Letters, 2009. 1(1): p. 249-253.
2. Thimsen, E. and P. Biswas, Nanostructured photoactive films synthesized by a flame aerosol reactor. AIChE journal, 2007. 53(7): p. 1727-1735.