Lateral electron transport inside a monolayer of derivatized fullerenes anchored

2019-12-14 06:43:52

electron oxide fullerene monolayer adsorbed

责任者: Papageorgiou, N.;Gratzel, M.;Enger, O.;Bonifazi, D.;Diederich, F. 单位: Departement de Chimie, Ecole Polytech. Fed. de Lausanne, Switzerland 来源出处: Journal of Physical Chemistry B(J. Phys. Chem. B (USA)),2002/04/18,106(15):3813-22 摘要: Carboxylated fullerene derivatives adsorbed on nanocrystalline ZrO2 films deposited on conducting glass, display reversible electrochemical behavior with currents being 200 times higher than measured on a monolayer of the redox active fullerene molecule adsorbed on the conducting support. Despite the insulating oxide layer on which the fullerene is adsorbed, cross-surface charge transfer results in the participation of the internal surface of the oxide in the redox process. A mechanism of charge transport involving electron injection from the conducting support, followed by lateral electron hopping within the fullerene monolayer on the oxide, is proposed. Apparent diffusion coefficients as high as 1.5 × 10-8 cm2 s-1 were measured for the electron hopping process. A percolation threshold for electronic conductivity was found at a surface coverage between 40 and 60% of a full monolayer. Co-adsorbed spacer molecules, however, were seen to modify the percolation limit, as no threshold was observed up to 60% fullerene coverage. Significant implications are envisaged with regard to prospective applications in e.g. nano-optoelectronics, electrochemical devices, sensors, solar cells, and redox targeting of adsorbed biomolecules 关键词: adsorbed layers;charge exchange;electrochemistry;electron mobility;fullerene compounds;hopping conduction;monolayers;nanostructured materials;percolation;lateral electron transport;anchored derivatised fullerene monolayer;nanocrystalline metal oxide films;carboxylated fullerene derivatives;nanocrystalline ZrO2 films;conducting glass;reversible electrochemical behavior;currents;redox active fullerene molecule;adsorbed fullerene;conducting support;insulating oxide layer;cross-surface charge transfer;internal surface;redox process;charge transport mechanism;lateral electron hopping;diffusion coefficients;electron hopping process;percolation threshold;electronic conductivity;surface coverage;full monolayer;co-adsorbed spacer molecules;percolation limit;fullerene coverage;nano-optoelectronics;electrochemical devices;sensors;solar cells;redox targeting;adsorbed biomolecules;nanocrystalline ceramic films