A novel velocity-matched distributed photodetector (VMDP) is proposed to simultaneously achieve high saturation photocurrent and broad bandwidth. Theoretical analysis on the tradeoff between saturation power and bandwidth shows that the VMDP offers fundamental advantages over conventional photodetectors. A comprehensive theoretical model has been developed for the design and simulation of the V...

Carbon nanotubes show vast potential to be used as building blocks for photodetection applications. However, measurements of fundamental optical properties, such as the absorption coefficient and the dielectric constant, have not been accurately performed on a single pristine carbon nanotube. Here we show polarization-dependent photocurrent spectroscopy, performed on a p-n junction in a single ...

Near-Ðeld photocurrent spectra of high-power laser diode arrays with di†erent wave-guide characteristics are reported. Subwavelength spatial resolution is achieved by using a near-Ðeld Ðbre probe as the excitation source. The e†ect of the laser diode waveguide structure and of surface recombination processes on the near-Ðeld photocurrent image formation is discussed and analysed in terms of a b...

Using a capacitive photocurrent measurement technique, we demonstrate the ability of both semiconducting and metallic single wall nanotubes to function as photodetectors over a wide spectral range. We observe clear peaks in the photo induced displacement current of a nanotube-plated capacitor that correspond directly to the semiconducting and metallic transitions in the nanotube absorbance spec...

We report on the first demonstration of velocity-matched distributed photodetectors and balanced photodetectors with p-i-n photodetectors. Record-high linear dc photocurrent of 45 mA has been achieved without suffering from thermal damage, thanks to the superior power handling capability of p-i-n photodiodes. A novel fiber alignment technique has been developed to achieve high linear photocurre...

A comprehensive model is presented of the internal photoemission in MOS systems, at low electric fields (| | < 104 V/cm) in the dielectric. Model equations are separately solved for the case of zero photocurrent (J = 0) and for nonzero photocurrent (J ≠ 0), allowing calculation of various photoelectric characteristics of MOS structures. These calculated characteristics are shown to remain in ex...

We experimentally studied the magneto-photocurrents generated by direct interband transition in InAs/GaSb type II superlattice. By varying the magnetic field direction, we observed that an in-plane magnetic field induces a photocurrent linearly proportional to the magnetic field; however, a magnetic field tilted to the sample plane induces a photocurrent presenting quadratic magnetic field depe...

Addition of methyl viologen (MV2+) enhances the anodic currents observed for Ti02 suspensions under illumination by trapping of photogenerated electrons with formation of MV’.. The magnitude of the photocurrent depends upon the relative location of the semiconductor Fermi level and Erdon of the MV2+/MV+. couple. The location of the Fermi level in the anatase powders was estimated as -0.05 V vs....