Date: November 3, 2021
Oleksandr Grynko with co-authors: Tristen Thibault, Emma Pineau, and Alla Reznik
published a paper titled “The X-ray Sensitivity of an Amorphous Lead Oxide Photoconductor” in
special issue: Sensors and X-ray Detectors. Congratulations on the published paper!
Abstract
The photoconductor layer is an important component of direct conversion flat panel X-ray
imagers (FPXI); thus, it should be carefully selected to meet the requirements for the X-ray
imaging detector, and its properties should be clearly understood to develop the most optimal
detector design. Currently, amorphous selenium (a-Se) is the only photoconductor utilized in
commercial direct conversion FPXIs for low-energy mammographic imaging, but it is not
practically feasible for higher-energy diagnostic imaging. Amorphous lead oxide (a-PbO)
photoconductor is considered as a replacement to a-Se in radiography, fluoroscopy, and
tomosynthesis applications. In this work, we investigated the X-ray sensitivity of a-PbO, one of
the most important parameters for X-ray photoconductors, and examined the underlying
mechanisms responsible for charge generation and recombination. The X-ray sensitivity in terms
of electron–hole pair creation energy, W±, was measured in a range of electric fields, X-ray
energies, and exposure levels. W± decreases with the electric field and X-ray energy, saturating
at 18–31 eV/ehp, depending on the energy of X-rays, but increases with the exposure rate. The
peculiar dependencies of W± on these parameters lead to a conclusion that, at electric fields
relevant to detector operation (~10 V/μm), the columnar recombination and the bulk
recombination mechanisms interplay in the a-PbO photoconductor.
Continue reading the article: https://doi.org/10.3390/s21217321
