Electron Transport Properties and Dielectric Breakdown of Alkyl Monolayers Chemisorbed on a Highly Doped n-Type Si(111) Surface

Abstract

We present a technique for atomic density measurements by the off-resonant phase shift induced on a two-frequency, coherently synthesized light beam. We have used this scheme to measure the column density of a magnetically trapped atom cloud and to monitor oscillations of the cloud in real time by making over a hundred non-destructive local density measurements. For measurements using pulses of 10 4 -10 5 photons lasting ∼10 µs, the precision is limited by statistics of the photons and the photodiode avalanche. We explore the relationship between measurement precision and the unwanted loss of atoms from the trap and introduce a figure of merit that characterizes it. This method can be used to probe the density of a Bose-Einstein condensate (BEC) with minimal disturbance of its phase.

Temperature dependence of current density and admittance in metal-insulator-semiconductor junctions with molecular insulator

“…4 Covalently bound linear saturated (n-alkyl) chains form robust molecular layers with a high coverage and play the role of a nanometer-thick tunnel barrier (TB); however, steric molecular constraints do not allow a full passivation of Si(111) surface sites which remain subject to post-grafting oxidation at the ambient. [5][6][7] Electrical transport properties of hybrid M-OML-SC devices have been widely studied [8][9][10][11][12][13][14][15][16][17][18][19] due to their relatively low density of electrically active defects at the OML-Si interface. [20][21][22][23] Analysis of current-voltage (I-V) characteristics of molecular MIS tunnel junctions (M-OML-SC) is still a controversial topic due to the simultaneous contribution of different mechanisms (tunneling, thermionic emission (TE), and generation-recombination) potentially involved in the transport of electrical charge carriers, in addition to some influence of series resistance at high current density.…”

“…[20][21][22][23] Analysis of current-voltage (I-V) characteristics of molecular MIS tunnel junctions (M-OML-SC) is still a controversial topic due to the simultaneous contribution of different mechanisms (tunneling, thermionic emission (TE), and generation-recombination) potentially involved in the transport of electrical charge carriers, in addition to some influence of series resistance at high current density. Several methods were proposed to analyze the direct current (dc) transport properties, [8][9][10][11][12][13][14][15][16][17][18][19] however, most studies were performed only at room temperature. In spite of some efforts to combine tunneling and thermionic emission transport through weighting parameters with little physical basis, 14,15 there is no clear method to evaluate the contribution of a thin (d T ¼ 1À2 nm) molecular tunnel barrier in the regime where both mechanisms contribute to the current.…”

“…Several methods were proposed to analyze the direct current (dc) transport properties, [8][9][10][11][12][13][14][15][16][17][18][19] however, most studies were performed only at room temperature. In spite of some efforts to combine tunneling and thermionic emission transport through weighting parameters with little physical basis, 14,15 there is no clear method to evaluate the contribution of a thin (d T ¼ 1À2 nm) molecular tunnel barrier in the regime where both mechanisms contribute to the current. The tunnel attenuation parameter, b 0 d T , is usually obtained at room temperature using junctions grafted with variable chain length (d T ); however the structure dependent b 0 values in these "nominally identical" junctions may be affected by different coverage or structural ordering.…”

Infrared spectroscopy of the organic monolayer sandwiched between a Hg electrode and a Si substrate

“…Several groups measured the current-voltage ͑I − V͒ characteristics for hydrocarbon monolayers with a liquid Hg electrode, [6][7][8][9][10][11][12][13][14][15][16] because Hg contacts softly and homogeneously with SAMs. Several groups measured the current-voltage ͑I − V͒ characteristics for hydrocarbon monolayers with a liquid Hg electrode, [6][7][8][9][10][11][12][13][14][15][16] because Hg contacts softly and homogeneously with SAMs.…”

“…Several groups measured the current-voltage ͑I − V͒ characteristics for hydrocarbon monolayers with a liquid Hg electrode, [6][7][8][9][10][11][12][13][14][15][16] because Hg contacts softly and homogeneously with SAMs. 6,[8][9][10][11][12][13][14]16,19 On the other hand, Ohmic contacts were achieved for Hg/hydrogen-terminated n-type Si structures, 6,15,16,20 because the electron affinity of the hydrogen-terminated n-Si and the workfunction of Hg are energetically close. 6,[8][9][10][11][12][13][14]16,19 On the other hand, Ohmic contacts were achieved for Hg/hydrogen-terminated n-type Si structures, 6,15,16,20 because the electron affinity of the hydrogen-terminated n-Si and the workfunction of Hg are energetically close.…”