skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Controlling processing temperatures and self-limiting behaviour in intense pulsed sintering by tailoring nanomaterial shape distribution
Title: Controlling processing temperatures and self-limiting behaviour in intense pulsed sintering by tailoring nanomaterial shape distribution
Intense Pulsed Light Sintering (IPL) uses pulsed, large-area, broad-spectrum visible light from a xenon lamp for rapid fusion of nanomaterials into films or patterns used in flexible sensors, solar cells, displays and other applications. Past work on the IPL of silver nanoparticles has shown that a self-damping coupling between densification and optical absorption governs the evolution of the deposited nanomaterial temperature during IPL. This work examines the influence of the nanomaterial shape distribution on this coupling and on the temperature evolution in IPL of silver nanowire–nanoparticle composite films. The film thickness, resistivity, micromorphology, crystallinity and optical properties are compared for varying ratios of nanowire to nanoparticle content in the film. It is shown for the first time, that increasing the nanowire content reduces the maximum film temperature during IPL from 240 °C to 150 °C and substantially alters the temperature evolution trends over consecutive pulses, while enabling film resistivity within 4–5 times that of bulk silver in 2.5 seconds of processing time. Nanoscale electromagnetic models are used to understand optical absorption as a function of changing ratio of nanowires to nanoparticles in a model assembly that emulates the IPL experiments performed here. The coupling between densification and optical absorption is found to inherently depend on the nanomaterial shape distribution and the ability of this phenomenon to explain the experimental temperature evolution trends is discussed. The implications of these observations for controlling self-damping coupling in IPL and the optimum nanoparticle to nanowire ratios for concurrently achieving high throughput, low processing temperatures, low material costs and low resistivity in IPL of conductive metallic nanomaterials are also described.  more » « less
Award ID(s):
1809289 1449383
PAR ID:
10063274
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
RSC Advances
Volume:
7
Issue:
89
ISSN:
2046-2069
Page Range / eLocation ID:
56395 to 56405
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, ASME 2016 11th International Manufacturing Science and Engineering Conference)
    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. 
    more » « less
  2. ; ; ; (, 2017 12th International Manufacturing Science and Engineering Conference MSEC2017)
    Copper sulphide (CuxS, x=1 to 2) is a metal chalcogenide semiconductor that exhibits useful optical and electrical properties due to the presence of copper vacancies. This makes CuxS thin films useful for a number of applications including infrared absorbing coatings, solar cells, thin-film electronics, and as a precursor for CZTS (Copper Zinc Tin Sulphide) thin films. Post-deposition sintering of CuxS nanoparticle films is a key process that affects the film properties and hence determines its operational characteristics in the above applications. Intense pulse light (IPL) sintering uses visible broad-spectrum xenon light to rapidly sinter nanoparticle films over large-areas, and is compatible with methods such as roll-to-roll deposition for large-area deposition of colloidal nanoparticle films and patterns. This paper experimentally examines the effect of IPL parameters on sintering of CuxS thin films. As-deposited and sintered films are compared in terms of their crystal structure, as well as optical and electrical properties, as a function of the IPL parameters. 
    more » « less
  3. ; ; ; (, Nanotechnology)
    Abstract Plasma technology is actively used for nanoparticle synthesis and modification. All plasma techniques share the ambition of providing high quality, nanostructured materials with full control over their crystalline state and functional properties. Pulsed-DC physical/chemical vapour deposition, high power impulse magnetron sputtering, and pulsed cathodic arc are consolidated low-temperature plasma processes for the synthesis of high-quality nanocomposite films in vacuum environment. However, atmospheric arc discharge stands out thanks to the high throughput, wide variety, and excellent quality of obtained stand-alone nanomaterials, mainly core–shell nanoparticles, transition metal dichalcogenide monolayers, and carbon-based nanostructures, like graphene and carbon nanotubes. Unique capabilities of this arc technique are due to its flexibility and wide range of plasma parameters achievable by modulation of the frequency, duty cycle, and amplitude of pulse waveform. The many possibilities offered by pulsed arc discharges applied on synthesis of low-dimensional materials are reviewed here. Periodical variations in temperature and density of the pulsing arc plasma enable nanosynthesis with a more rational use of the supplied power. Parameters such as plasma composition, consumed power, process stability, material properties, and economical aspects, are discussed. Finally, a brief outlook towards future tendencies of nanomaterial preparation is proposed. Atmospheric pulsed arcs constitute promising, clean processes providing ecological and sustainable development in the production of nanomaterials both in industry and research laboratories. 
    more » « less
  4. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Optical Materials)
    Abstract Photonic integrated circuits require various optical materials with versatile optical properties and easy on‐chip device integration. To address such needs, a well‐designed nanoscale metal‐oxide metamaterial, that is, plasmonic Au nanoparticles embedded in nonlinear LiNbO3(LNO) matrix, is demonstrated with tailorable optical response. Specifically, epitaxial and single‐domain LNO thin films with tailored Au nanoparticle morphologies (i.e., various nanoparticle sizes and densities), are grown by a pulsed laser deposition method. The optical measurement presents obvious surface plasmon resonance and dramatically varied complex dielectric function because of the embedded Au nanoparticles, and its response can be well tailored by varying the size and density of Au nanoparticles. An optical waveguide structure based on the thin film stacks of a‐Si on SiO2/Au‐LNO is fabricated and exhibits low optical dispersion with an optimized evanescent field staying in the LNO‐Au active layer. The hybrid Au‐LNO metamaterial thin films provide a novel platform for tunable optical materials and their future on‐chip integrations in photonic‐based integrated circuits. 
    more » « less
  5. (, 2017 Manufacturing Science and Engineering Conference)
    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. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email