AlGaN/GaN metal–semiconductor–metal (MSM) ultraviolet (UV) photodetectors with photo-chemical vapour deposition (photo-CVD) annealed Ni/Au semi-transparent contacts were fabricated. It was found that the transmittances of Ni/Au films increased while the photodetector dark currents became significantly lower after annealing. With a 5 V applied bias, it was found that the photocurrent to dark cur...

Nonlinearities due to photodetector saturation limit the maximum dynamic range achievable in short fiber optic links. We demonstrate an adaptive method for photodetector linearization using a monolithic CMOS polynomial generator. Improvements of 16 dB and 5.1 dB are achieved in the 2 and 3 order limited dynamic ranges, respectively.

Here, we report a dual-band plasmonic photodetector based on Ga-polar gallium nitride (GaN) for highly sensitive detection of UV and green light. We discover that decoration of Au nanoparticles (NPs) drastically increases the photoelectric responsivities by more than 50 times in comparition to the blank GaN photodetector. The observed behaviors are attributed to polarization enhanced charge tra...

Photoelectron transport in a photodetector in an ultra-high frame rate image sensor under the uniform illumination condition is investigated. The charge readout time in a multi-implant photodetector is estimated using a generalized model with both diffusion equation and continuity equations. The maximum effective diffusion length was assigned to each implanted region after taking into account t...

We present a C-shaped nanoaperture-enhanced Ge photodetector that shows 2-5 times the photocurrent enhancement over that from a square aperture of the same area at 1310 nm wavelength. We demonstrate the polarization dependence of the C-aperture photodetector over a wide wavelength range. Our experimental observation agrees well with finite-difference time-domain simulation results.

Organic photodetectors (OPDs) are potentially useful in many applications because of their light weight, flexibility and good form factors. Despite the high detectivities that have been frequently reported for OPDs recently, the application of these OPDs for weak light detection has been rarely demonstrated. In this thesis, low noise, high gain photodetectors based on organic and ZnO nanopartic...

We present a novel MSM (metal-semiconductor-metal) based tunable photodetector for discrimination between two wavelengths with a 365GHz channel spacing. If integrated with CMOS circuits, this photodetector has the potential to perform high-speed channel switching in WDM-based systems. With increasing data traffic load in telecommunications networks, wavelength division multiplexing (WDM) is ess...

Silicon based metal-semiconductor-metal (MSM) photodetectors have faster photogeneration and carrier collection across the metal-semiconductor Schottky contacts, and CMOS integratibility compared to conventional p-n junction photodetectors. However, its operations are limited by low photogeneration, inefficient carrier-separation, and low mobility. Here, we show a simple and highly effective ap...

Carbon nanotubes are promising nanoscale materials for novel electrical, mechanical, chemical, and biological device and sensors based on its outstanding properties. Single walled carbon nanotubes can be either semiconducting or metallic material depending on its structures. However, controlling the structure is quite challenging with current technologies. For the network formation of the singl...

In this paper, the characteristics and a model of a side illuminated twin waveguide, pin-photodiode based on scattering parameters, is proposed. The equivalent small-signal model involves both the photodetector and the coplanar waveguide transmission line models. The measurement of the optoelectronic conversion parameter (S21) of photodetector at 1.55 μm is done by an optical heterodyne techniq...