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
