Carbon nanotube (CNT) photodiodes are a promising system for high-efficiency photocurrent generation due to the strong Coulomb interactions that can drive carrier multiplication. If the Coulomb interactions are too strong, however, exciton formation can hamper photocurrent generation. Here, we explore, experimentally and theoretically, the effect of the environmental dielectric constant...
Suspended metallic carbon nanotubes (m-CNTs) exhibit a remarkably large transport gap that can exceed 100 meV. Both experiment and theory suggest that strong electron-electron interactions play a crucial role in generating this electronic structure. To further understand this strongly-interacting system, we have performed electronic measurements of suspended m-CNTs with known...
Many carbon nanotube (CNT) applications require precisely controlled chemical
functionalization that is minimally disruptive to electrical performance. A promising approach is
the generation of sp³ hybridized carbon atoms in the sp²-bonded lattice. We have investigated the
possibility of using a carboxylic acid functionalized diazonium reagent to introduce a defined
number...
Many carbon nanotube (CNT) applications require precisely controlled chemical
functionalization that is minimally disruptive to electrical performance. A promising approach is
the generation of sp³ hybridized carbon atoms in the sp²-bonded lattice. We have investigated the
possibility of using a carboxylic acid functionalized diazonium reagent to introduce a defined
number...
To determine the thermal noise limit of graphene biotransistors, we have measured the complex impedance between the basal plane of single-layer graphene and an aqueous electrolyte. The impedance is dominated by an imaginary component but has a finite real component. Invoking the fluctuation–dissipation theorem, we determine the power spectral density...
To determine the thermal noise limit of graphene biotransistors, we have measured the complex impedance between the basal plane of single-layer graphene and an aqueous electrolyte. The impedance is dominated by an imaginary component but has a finite real component. Invoking the fluctuation–dissipation theorem, we determine the power spectral density...
Using a graphene field-effect transistor biosensor, we monitored the pH inside a living biofilm
with fast temporal resolution (~ 1 s) over multi-hour time periods. The atomically-thin sensor is
positioned between the biofilm and a supporting silicon oxide surface, providing non-invasive
access to conditions at the base of the biofilm....
Using a graphene field-effect transistor biosensor, we monitored the pH inside a living biofilm
with fast temporal resolution (~ 1 s) over multi-hour time periods. The atomically-thin sensor is
positioned between the biofilm and a supporting silicon oxide surface, providing non-invasive
access to conditions at the base of the biofilm....
Ion pairs and solubility related to ion-pairing in water influence many processes in nature and in synthesis including efficient drug delivery, contaminant transport in the environment, and self-assembly of materials in water. Ion pairs are difficult to observe spectroscopically because they generally do not persist unless extreme solution conditions are...
PN junctions in nanoscale materials are of interest for a range of technologies including photodetectors, solar cells, and light-emitting diodes. However, Schottky barriers at the interface between metal contacts and the nanomaterial are often unavoidable. The effect of metal-semiconductor interfaces on the behavior of nanoscale diodes must be understood, both...