Show simple item record

dc.contributor.authorGhanbarzadeh, Sina 19:39:22 (GMT) 05:00:22 (GMT)
dc.description.abstractThe most promising technology for radiography is active matrix flat panel imaging systems (AMFPI). However, AMFPI systems are relatively expensive in comparison with conventional computed radiography (CR) systems. Therefore for general radiography applications low cost systems are needed, especially in hospitals and healthcare systems of the developing countries. The focus of this research is the fabrication and characterization of a low cost amorphous silicon metal-semiconductor-metal photodetector as a photosensitive element in a AMFPI systems. Metal-Semiconductor-Metal photodetectors (MSM-PD) are attractive as sensors due to their ease of fabrication and compatibility with thin film transistor fabrication process primarily because there is no p+ doped layer in comparison with conventional p-i-n photodiodes. We have reported low dark current lateral a-Si MSM-PD (lower than 20pA/mm2 ) with responsivity of 280mA/W and EQE of 65 percent to green light ( l = 525nm). These improvement are achieved by introduction of a PI blocking layer and operating the device at high electric field (15 V/µm). This new structure eliminates the need of p+ and n+ layers which makes this structure fully compatible with the a-Si:H TFT fabrication process and consequently a low cost flat panel imager. Further, in this study we have investigated the effect of the spacing and width of the comb structure in the proposed lateral a-Si MSM-PD to determine the best configuration. Moreover, a-Si MSM-PD with PI blocking layer shows a linear behaviour to the photon flux in the wide range of 200nW/cm2 - 300µW/cm2 intensity of the incoming light. In comparison to vertical p-i-n structures, the reported MSM lateral device shows gains in terms of dynamic range, ease of fabrication (no p+ layer) without any deterioration in EQE and responsivity. This results are promising and encourage the development of a-Si lateral MSM-PD for indirect conversion large area medical imaging applications and especially low cost flat.en
dc.publisherUniversity of Waterlooen
dc.subjectAmorphous Siliconen
dc.subjectIndirect conversion X-ray imagingen
dc.subjectDark currenten
dc.subjectMSM photodetectorsen
dc.titleHigh Performance, Low Cost Lateral Metal-Semiconductor-Metal Photodetector for Large Area Indirect X-Ray Imagingen
dc.typeMaster Thesisen
dc.subject.programElectrical and Computer Engineeringen
dc.description.embargoterms1 yearen and Computer Engineeringen
uws-etd.degreeMaster of Applied Scienceen

Files in this item


This item appears in the following Collection(s)

Show simple item record


University of Waterloo Library
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
519 888 4883

All items in UWSpace are protected by copyright, with all rights reserved.

DSpace software

Service outages