In this work, a semi-analytical model, based on a thorough analysis of experimental data, is developed for photoresponse estimation of a photodiode-based CMOS active pixel sensor (APS). The model covers the substrate diffusion effect together with the influence of the photodiode active-area geometrical shape and size. It describes the pixel response dependence on integration photocarriers and c...

CMOS image sensor designers take advantage of technology scaling either by reducing pixel size or by adding more transistors to the pixel. In both cases, the distance from the chip surface to the photodiode increases relative to the photodiode planar dimensions. As a result, light must travel through an increasingly deeper and narrower "tunnel" before it reaches the photodiode. This is especial...

A 0.5 V CMOS light-to-digital converter (LDC) based on a nonuniform quantizer and off-chip photodiode enables a photodiode bias current range spanning 4 nA to 3.5 A while consuming less than 4 W of power. Using an off-chip LED as a modulated light source, measurements with a photodiode current signal having modulation frequency of 1.2 Hz (72 beats per minute) and 0.5% peak-to-peak amplitude rel...

INTRODUCTION A fast, efficient and reliable switch is the basic ingredient of a pulse power accelerator. -Two switches have been proposed so far: the solid state switch, and the vacuum photodiode switch. The solid state version has been tested to some extent, albeit at low (few kilovolts) level, with risetime around 10 ps in the radial line transformer configuration! The vacuum photodiode is be...

Title of thesis: CLOSED-LOOP CONTROL OF A MICROPOSITIONER USING INTEGRATED PHOTODIODE SENSORS Mustafa Ilker Beyaz, Master of Science, 2008 Directed by: Professor Reza Ghodssi Department of Electrical and Computer Engineering A closed-loop control system with photodiode position sensors has been implemented in a microball bearing supported linear electrostatic micromotor to improve accuracy and ...

We report on tuning of the interfacial properties of a highly sensitive organic photodiode by introducing a buffer layer between the anode and the semiconductor layer. The effects of different buffer layers consisting of a self-assembled monolayer (SAM), PEDOT:PSS, and pentacene on the morphology and crystallinity of the upper-deposited bulk heterojunction semiconductor layer are carefully anal...

In this study three commercial semiconductor devices were characterized in the laboratory for computed tomography dosimetry: one photodiode and two phototransistors. It was evaluated four responses to the irradiation: dose linearity, energy dependence, angular dependence and loss of sensitivity after X ray exposure. The results showed that the three devices have proportional response with the a...

A novel and simple approach to optical wavelength measurement is presented in this paper. The working principle is demonstrated using a tunable waveguide micro ring resonator and single photodiode. The initial calibration is done with a set of known wavelengths and resonator tunings. The combined spectral sensitivity function of the resonator and photodiode at each tuning voltage was modeled by...

Sensor fill factor is one of the key pixel design requirements for high performance imaging arrays. In our conventional imaging pixel architecture with a TFT and a photodiode deposited in the same plane, the maximum area that the photodiode can occupy is limited by the size of the TFT and the surrounding metal lines. A full fill factor array design was previously proposed using a continuous sen...

Thanks to its extreme optical and electronic properties, diamond appears to be a promising semiconducting material for photon detection. Its wide band-gap, 5.5 eV, results in a very low leakage current and its electronic properties as high carrier mobility allow fast time response (J. E. Field, 1979). Besides, it has a large breakdown electric field (∼10 V/┤m), a low dielectric constant (i.e. l...