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WE‐A‐201B‐03: Resistive Interface Layer for Flat‐Panel Imager (FPI) with Avalanche Gain
Author(s) -
Hsiao H,
Zhao W
Publication year - 2010
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3469335
Subject(s) - resistive touchscreen , materials science , optics , optoelectronics , scintillator , avalanche photodiode , detector , electrical resistivity and conductivity , resistor , deposition (geology) , noise (video) , atomic layer deposition , layer (electronics) , electrical engineering , computer science , physics , voltage , nanotechnology , paleontology , artificial intelligence , sediment , image (mathematics) , biology , engineering
Purpose: The low dose performance of existing solid‐state flat panel imagers (FPI) are degraded by electronic noise. To overcome this problem, we have proposed a new FPI concept. It employs a structured Csl scintillator to convert incident x‐rays to optical photons, which is converted to amplified electronic signal by a thin (∼15 microns) amorphous selenium (a‐Se) photoconductor with avalanche multiplication gain. One critical component of this detector is the resistive interface layer (RTL) which provides protection of electrical breakdown under high electric field (>100V/um) required for avalanche multiplication. Method and Material: Using physics model and simulation, we estimated the desirable range of resistivity and thickness of RIL to a while maintaining good spatial resolution and image lag. Material deposition procedures were developed to achieve these RIL properties. Results: Our investigation found that RIL with resistivity in the range of 10̂10 to 10̂12 ohm‐cm and with thickness of 2 microns (with solution based deposition methods) could provide satisfactory imaging performance. RIL material based on mixing insulating polymers with conductive fillers provides great versatility for our purpose.