Controlling Conductive Filament and Tributyrin Sensing Using an Optimized Porous Iridium Interfacial Layer in Cu/Ir/TiNxOy/TiN

Mrinmoy Dutta, Siddheswar Maikap, Jiantai Timothy Qiu

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


Controlling the copper (Cu) filament using an optimized porous iridium (Ir) interfacial layer thickness ranging from 2 to 20 nm in a Cu/Ir/TiNxOy/TiN resistive switching memory device is investigated for the first time. Transmission electron microscopy (TEM) shows a porous Ir layer, and X-ray photoelectron spectroscopy (XPS) is performed to determine the Ir0, Ir3+/Ir4+ oxidation states, which are responsible for a super-Nernstian pH sensitivity of 125.5 mV pH−1 as well as a low concentration of 1 × 10−12m tributyrin detected using a 40 nm thick Ir in Ir/TiNxOy/TiN structure. The 5 nm thick Ir layer in the Cu/Ir/TiNxOy/TiN structure shows current–voltage switching characteristics for 3000 consecutive cycles, a stable RESET voltage, a long program/erase (P/E) endurance of >109 cycles under a P/E current of 300 µA at a high speed of 100 ns, and neuromorphic phenomena compared to those of other Ir thicknesses. Cu migration into the TiNxOy oxide-electrolyte is shown by TEM observations. The tributyrin detection ranging from 1 × 10−12 to 100 × 10−12m using a resistive switching memory device paves the way for the early diagnosis of human diseases as well as artificial intelligence applications in the near future.

Original languageEnglish
Article number1800288
JournalAdvanced Electronic Materials
Issue number2
Publication statusPublished - Feb 2019
Externally publishedYes


  • controlling filament
  • interfacial layer
  • pH sensitivity
  • porous Ir
  • tributyrin detection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials


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