Sintering of nanoparticles deposited onto rigid or flexible substrate is required for many devices that use continuous and patterned thin films. An emerging need in this area is to perform nanoparticle sintering under ambient conditions, at high speeds, and with throughput that is compatible with high speed nanoparticle deposition techniques. Intense Pulsed Light sintering (IPL) uses a high energy, broad area and broad spectrum beam of xenon lamp light to sinter metallic and non-metallic nanoparticles. The capability of IPL to meet the above needs has been demonstrated. This paper experimentally examines temperature evolution and densification during IPL. It is shown, for the first time, that temperature rise and densification in IPL are related to each other. A coupled optical-thermal-sintering model on the nanoscale is developed, to understand this phenomenon. This model is used to show that the change in nanoscale shape of the nanoparticle ensemble due to sintering, reduces the optically induced heating as the densification proceeds, which provides a better explanation of experimental observations as compared to current models of IPL. The implications of this new understanding on the performance of IPL are also discussed.
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EFFECT OF PARTICLE SHAPE ON NECK GROWTH AND SHRINKAGE OF NANOPARTICLES
Sintering of nanoparticles to create films and patterns of functional materials is emerging as a key manufacturing process in applications like flexible electronics, solar cells and thin-film devices. Further, there is the emerging potential to use nanoparticle sintering to perform additive manufacturing as well. While the effect of nanoparticle size on sintering has been well studied, very little attention has been paid to the effect of nanoparticle shape on the evolution of sintering. This paper uses Molecular dynamics (MD) simulations to determine the influence of particle shape on shrinkage and neck growth for two common nanoparticle shape combinations, i.e., sphere-sphere and sphere-cylinder nanoparticles of different sizes. These sintering indicators are examined at two different temperature ramps. The results from this work show that depending on their relative sizes, degree of neck growth and shrinkage are both significantly affected by the nanoparticle shape. The possibility of using this phenomenon to control density and stresses during nanoparticle sintering are discussed.
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- Award ID(s):
- 1809289
- NSF-PAR ID:
- 10063289
- Date Published:
- Journal Name:
- 2017 Manufacturing Science and Engineering Conference
- Page Range / eLocation ID:
- 6
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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