Title :
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
fDate :
6/20/1905 12:00:00 AM
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. The 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 TIBr are compared to other materials, and possible solutions are discussed
Keywords :
CVD coatings; photoconductivity; radiation detection; semiconductor counters; thallium compounds; 100 mum; 200 mum; TlBr; columnar structure; high density; high gain; inherent high effective atomic number; low field strengths; polycrystalline TlBr films; radiographic detectors; vapor deposited films; Atomic layer deposition; Atomic measurements; Conducting materials; Conductivity; Cooling; Detectors; Photoconducting materials; Photoconductivity; Radiography; Testing;
Conference_Titel :
Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE
Print_ISBN :
0-7803-5021-9
DOI :
10.1109/NSSMIC.1998.775231
