Active pixels of Transverse Field Detector ...

Active pixels of Transverse Field Detector: Device, Electronics and Colorimetric Performance

Cesare Buffa
DEI PhD Student

Building 24 - Via Golgi 40
Room Beta
November 15th, 2011
at 6.30 p.m.

Abstract:

In recent years the market of solid-state image sensors has seen an explosive growth due to the increasing demands of mobile imaging, digital still and video cameras, surveillance and other applications. Image sensors are typically arranged in a matrix of pixels to operate the spatial sampling of the optical image. Traditional sensors make use of color-sensitive filter array (CFA) in order to make each pixel sensitive only to one color of the CFA pattern. Other color separation methods and new geometries have been proposed in order to increase sensitivity and quantum efficiency. New techniques for color detection and new image sensors structures have great interest in the research field.
A novel color-sensitive semiconductor detector has recently been proposed by a research group of Dipartimento di Elettronica e Informazione. The device (named Transverse Field Detector) can be used to measure the color of the incident light without any color filter. The working principle is based on the capability of this device to collect the carriers, generated at different depths, at different superficial junctions by means of suitable transverse electric fields. Due to the differences in the semiconductor light absorption coefficient at different wavelengths, this device can perform color separation.
This seminar deals with the design, implementation and experimental characterization of active pixels of TFD, focusing on isolation among pixels in a matrix, on the integration of a charge preamplifier at pixel level and, finally, on the optimization of spectral responses.

Research area:
Sensors and instrumentation