Controlled dielectrophoretic nanowire self-assembly using atomic layer deposition and suspended microfabricated electrodes

Abstract

Effects of design and materials on the dielectrophoretic self-assembly of individual gallium nitride nanowires (GaN NWs) onto microfabricated electrodes have been experimentally investigated. The use of TiO(2) surface coating generated by atomic layer deposition (ALD) improves dielectrophoretic assembly yield of individual GaN nanowires on microfabricated structures by as much as 67%. With a titanium dioxide coating, individual nanowires were placed across suspended electrode pairs in 46% of tests (147 out of 320 total), versus 28% of tests (88 out of 320 total tests) that used uncoated GaN NWs. An additional result from these tests was that suspending the electrodes 2.75 μm above the substrate corresponded with up to 15.8% improvement in overall assembly yield over that of electrodes fabricated directly on the substrate.

Enhanced DC-Operated Electroluminescence of Forwardly Aligned p/MQW/n InGaN Nanorod LEDs via DC Offset-AC Dielectrophoresis

“…Using the same theory and technology, the number of studies regarding AC-field DEP processes has steadily increased over the years, leading to the successful assembly of 1D nanostructures on predefined electrodes. − Specifically, GaN-based semiconductor nanowires/nanorods − as well as metallic nanostructures , and carbon nanotubes , can also be assembled on prepatterned electrodes using the AC-field DEP process, which offers the strong advantage of being able to assemble millions of nanowires on a specified area. Over the last decade, GaN-based nanowires/nanorods were assembled onto electrodes using the DEP process, as summarized in Table . ,,,− As shown in several studies, GaN nanowires/nanorods have a high aspect ratio (length/diameter of nanowires/nanorods) and can be aligned onto electrodes using the DEP process even at low AC voltages. Park et al fabricated a blue LED device consisting of GaN nanorods LED with a relatively low aspect ratio using a DEP process at an AC voltage of only 6 V pp (peak-to-peak voltage) at 1 MHz, but it was not a surface-planar light source .…”

Development of a Triboelectric Nanogenerator for Joining of Silver Nanorods

“…Ag NRs on the Kapton were subjected to DEP, Lennard-Jones potential, and Coulomb forces. It was observed that DEP accumulates NRs near the tip of another NR to assist the joining process and for a cylindrical rod parallel to an electric field, it could be estimated using Equation (3) [53] π…”

“…Ag NRs on the Kapton were subjected to DEP, Lennard–Jones potential, and Coulomb forces. It was observed that DEP accumulates NRs near the tip of another NR to assist the joining process and for a cylindrical rod parallel to an electric field, it could be estimated using Equation () [ 53 ] $$\[ \begin{array}{*{20}{c}}{{{\vec{F}}_{{\rm{DEP}}}} = \frac{{\pi {r^2}L}}{2}\;{\varepsilon _{\rm{m}}}Re\left[ {{f_{{\rm{CM}}}}} \right]\vec{\nabla }{{\left| {{{\vec{E}}_{{\rm{rms}}}}} \right|}^2}}\end{array} \]$$where r is the radius, L is the length of NRs, Re[f CM ] is the real part of the Clausius–Mossotti factor, E rms is the root‐mean‐square electric field, and ε m is the real part of the complex permittivity of the surrounding medium of NRs. Obviously, electrophoresis force depends on the gradient of the electric field.…”

Recent Advances in Directed Assembly of Nanowires or Nanotubes

“…The alignment result depends on the electric voltage and frequency, as well as configurations and patterns of the electrodes. NWs have been assembled using DEP in high concentrations [59][60][61][62][63][64][65][66][67][68][69][70][71] or as individual entities [59][60][61][72][73][74]. For example, C. Chen [71] fabricated and integrated single-wall carbon nanotubes(SWCNTs) using DEP assembly, as shown in Fig.…”