Insulator-protected mechanically controlled break junctions for measuring single-molecule conductance in aqueous environments | Zendy

Nandini Muthusubramanian | Zendy; E. Galan | Zendy; Chandan Maity | Zendy; Rienk Eelkema | Zendy; Ferdinand C. Grozema | Zendy; Herre S. J. van der Zant | Zendy

Open Access

Insulator-protected mechanically controlled break junctions for measuring single-molecule conductance in aqueous environments

Author(s) -

Nandini Muthusubramanian,

E. Galan,

Chandan Maity,

Rienk Eelkema,

Ferdinand C. Grozema,

Herre S. J. van der Zant

Publication year - 2016

Publication title -

applied physics letters

Language(s) - English

Resource type - Journals

SCImago Journal Rank - 1.182

H-Index - 442

eISSN - 1077-3118

pISSN - 0003-6951

DOI - 10.1063/1.4955273

Subject(s) - conductance , materials science , oxide , aqueous solution , electrode , molecule , atomic layer deposition , insulator (electricity) , aluminum oxide , layer (electronics) , coating , nanotechnology , analytical chemistry (journal) , aluminium , optoelectronics , chemistry , composite material , mathematics , organic chemistry , combinatorics , chromatography , metallurgy

We present a method to fabricate insulated gold mechanically controlled break junctions (MCBJ) by coating the metal with a thin layer of aluminum oxide using plasma enhanced atomic layer deposition. The Al₂O₃ thickness deposited on the MCBJ devices was varied from 2 to 15 nm to test the suppression of leakage currents in deionized water and phosphate buffered saline. Junctions coated with a 15 nm thick oxide layer yielded atomically sharp electrodes and negligible conductance counts in the range of 1 to 10^-4 G₀ (1 G₀ = 77 μS), where single-molecule conductances are commonly observed. The insulated devices were used to measure the conductance of an amphiphilic oligophenylene ethynylene derivative in deionized water.