Berlin 2008 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 22: Transport: Poster Session

TT 22.53: Poster

Mittwoch, 27. Februar 2008, 14:00–18:00, Poster B

Observation of Coulomb blockade in diamond-like carbon films — •Savcho Tinchev¹, Evgenia Valcheva², and Sashka Alexandrova³ — ¹Institute of Electronics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, 1784 Sofia, Bulgaria — ²Physics Department, Sofia University, J. Bourchier 5, 1164 Sofia, Bulgaria — ³Institute of Solid State Physics, Bulgarian Academy of Sciences, Tzarigradsko Chaussee 72, 1784 Sofia, Bulgaria

Coulomb blockade of tunneling is a phenomenon observed in low capacitance tunnel junctions usually at low temperatures. To fabricate single electron devices operating at room temperatures it is essential to obtain nano-sized quantum dots or nanostructures with sizes below 10 nm, because the charging energy can overcome the thermal energy only in such small structures. Dimensions below 10 nm are, however, below the resolution limit of the electron beam lithography. Therefore self-organization processes are promising candidates for preparing electron devices operating at room temperatures.

We report here on observation of Coulomb blockade in diamond-like carbon (DLC) films at room temperature. Diamond-like carbon films used in our experiments were amorphous hydrogenated carbon films (a-C:H) made by DC PECVD from a mixture of benzene and argon. Nonlinear current voltage characteristics with a threshold voltage of about 3 volts and in some cases also step-like structures, known as Coulomb staircase were observed in diamond like carbon films. We interpret this observation as a clear manifestation of Coulomb blockade found for the first time in these films.