Conducting polymer formed by low energy gold ion implantation

Abstract

A buried conducting layer of metal/polymer nanocomposite was formed by very low energy gold ion implantation into polymethylmethacrylate. The conducting layer is ∼3 nm deep and of width ∼1 nm. In situ resistivity measurements were performed as the implantation proceeded, and the conductivity thus obtained as a function of buried gold concentration. The measured conductivity obeys the behavior well established for composites in the percolation regime. The critical concentration, below which the polymer remains an insulator, is attained at a dose ∼1.0×1016 atoms/cm2 of implanted gold ions.

Gold-implanted shallow conducting layers in polymethylmethacrylate

“…For our system of PMMA implanted with low energy gold ions the conductivity process is due only to percolation and the contribution from tunneling conduction is negligible. 35,36 Importantly, we point out that for the low ion energy used here, 49 eV, the implantation process does not create any target vacancies ͑H, C, or O͒, either directly from the implanted Au ions or from the collision cascade; for Au ions implanted into PMMA, SRIM ͑Ref. 27͒ reveals that vacancy formation requires a minimum ion energy of greater than 100 eV.…”

“…35 Briefly, electron transport through granular materials consisting of small conducting regions embedded in an insulating medium can occur through either of two possible processes or their combination. When the conducting elements are in geometric contact the process is called percolation; 36 percolation refers to the flow of current through random resistor networks.…”

Structure of disordered gold-polymer thin films using small angle x-ray scattering

“…7,8 In the work described here, we have used SAXS and the appropriate theoretical models [4][5][6][7][8][9] to determine the disordered structure of polymethylmethacrylate ͑PMMA͒-Au composite films. These kinds of composites possess interesting and technologically important electrical, [10][11][12] lithographic, 13 and optical properties. 11,12,14,15 The films investigated here were made by implanting gold ions at very low energy ͑about 49 eV͒ into PMMA polymer; ͑very low energy ion implantation is often referred to as "subplantation," and this is the appropriate terminology here͒.…”

Cell adhesion and growth on surfaces modified by plasma and ion implantation

“…16 Silver nanoparticles are known for their antibacterial properties. 17 As it is known that implantation of metal into polymer using ion implantation forms nanoparticles inside the polymer, [18][19][20][21][22][23][24][25][26] we evaluated the cell growth on buried silver nanoparticles into SU-8 formed by ion implantation. PDMS is a widely used polymeric material with several interesting characteristics, which include high flexibility, optical transparency, biocompatibility, and ease to fabricate.…”