Characterization of polycrystalline TlBr films for radiographic detectors

Author

Bennett, P.R. ; Shah, K.S. ; Cirignano, L.J. ; Klugerman, M.B. ; Moy, L.P. ; Olschner, F. ; Squillante, M.R.

Author_Institution

Radiat. Monitoring Devices Inc., Watertown, MA, USA

Volume

46

Issue

3

fYear

1999

fDate

6/1/1999 12:00:00 AM

Firstpage

266

Lastpage

270

Abstract

Vapor deposited films of thallium bromide are evaluated as potential photoconductive layers in new large-area radiographic detectors. The attractiveness of the material lies in its inherent high effective atomic number and high density. Polycrystalline films up to 200 μm have been grown and show a columnar structure with grains reaching 100 μm in diameter. Current-voltage (IV) tests indicate a bulk resistivity of 10⁹-10¹⁰ Ω·cm, limited by ionic conduction. Instability of current with time is also observed, but it can be minimized with cooling. The films demonstrate high gain at relatively low field strengths as compared to other photoconductive layers. Benefits and drawbacks of TlBr are compared to other materials, and possible solutions are discussed

Keywords

X-ray detection; diagnostic radiography; semiconductor counters; semiconductor thin films; thallium compounds; vapour deposited coatings; wide band gap semiconductors; TlBr; bulk resistivity; inherent high effective atomic number; ionic conduction; low field strengths; photoconductive layers; polycrystalline TlBr films; polycrystalline films; radiographic detectors; thallium bromide; Atomic layer deposition; Atomic measurements; Conducting materials; Conductivity; Cooling; Detectors; Photoconducting materials; Photoconductivity; Radiography; Testing;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/23.775525

Filename

775525