Due to their small size and high electrical conductivity, carbon nanotubes (NT) have emerged as one of the most promising nanomaterials for biological and biomedical sensing applications. We have developed an optoelectronic imaging system which combines NT transistors with optical trapping techniques and scanning photocurrent microscopy to investigate the interaction between a suspended carbon ...

Uniform photocurrent densities can be achieved in waveguide photodetectors by tailoring the extension length of an index-matching layer in eont of the diode. We demonstrate up to 9dB improvement in RF linearity at 2OGHz. Introduction: Spur hx Dynamic Range (SFDR), RF insertion loss and signal to noise ratio of analog fiber optic links improve with increasing maximum linear photocurrent [I]. The...

Highly sensitive DNA methyltransferase (MTase) activity and inhibitor screening photoelectrochemical (PEC) assay was developed based on the exciton energy transfer (EET) effect coupled with site-specific cleavage of restriction endonuclease (HpaII). The assay was designed by integrating the Au nanoparticles (NPs) labeled probe DNA (pDNA-Au) with CdSe quantum dots (QDs). The strong EET effect be...

We report on electrical and optical properties of p+-i-n+ photodetectors/solar cells based on square millimeter arrays of InP nanowires grown on InP substrates. The study includes a sample series where the p+-segment length was varied between 0 and 250nm, as well as solar cells with 9.3% efficiency with similar design. The electrical data for all devices display clear rectifying behavior with a...

In this study we investigate the electronic transport, the optical properties, and photocurrent in two-dimensional arrays of silicon nanocrystals (Si NCs) embedded in silicon dioxide, grown on quartz and having sizes in the range between less than 2 and 20 nm. Electronic transport is determined by the collective effect of Coulomb blockade gaps in the Si NCs. Absorption spectra show the well-kno...

Tunneling between a photoexcited p-type silicon tip and a gold surface is studied as a function of tip bias, tip-sample distance, and light intensity. In order to extend the range of application of future spin injection experiments, the measurements are carried out under nitrogen gas at room temperature. It is found that, while tunneling of valence band electrons is described by a standard proc...

The generation of a current by light is a key process in optoelectronic and photovoltaic devices. In band semiconductors, depletion fields associated with interfaces separate long-lived photo-induced carriers. However, in systems with strong electron-electron and electron-phonon correlations it is unclear what physics will dominate the photoresponse. Here, we investigate photocurrent in VO(2), ...

In this paper we report, for the first time, the alignment enhanced photoconductivity of single wall carbon nanotube films upon laser illumination. The photoconductivity exhibited an increase, decrease or even 'negative' values when the laser spot was on different positions between contact electrodes, showing a 'position' dependent photoconductivity of partially aligned films of carbon nanotube...

The photo-Dember effect arises from the asymmetric diffusivity of photoexcited electrons and holes, which creates a transient spatial charge distribution and hence the buildup of a voltage. Conventionally, a strong photo-Dember effect is only observed in semiconductors with a large asymmetry between the electron and hole mobilities, such as in GaAs or InAs, and is considered negligible in graph...

In this work, we report for the first time the entrapment of the biomolecular supercomplex Photosystem I (PSI) within a conductive polymer network of polyaniline via electrochemical copolymerization. Composite polymer-protein films were prepared on gold electrodes through potentiostatic electropolymerization from a single aqueous solution containing both aniline and PSI. This study demonstrates...