Amorphous selenium and its alloys from early xeroradiography to high resolution X‐ray image detectors and ultrasensitive imaging tubes

  title={Amorphous selenium and its alloys from early xeroradiography to high resolution X‐ray image detectors and ultrasensitive imaging tubes},
  author={Safa O. Kasap and Joel B. Frey and George Belev and Olivier Tousignant and Habib Mani and Luc Laperri{\`e}re and Alla Reznik and John A. Rowlands},
  journal={physica status solidi (b)},
We describe the progress in the science and technology of stabilized a‐Se from its early use in xerography and xeroradiography to its present use in commercial modern flat panel X‐ray imagers and ultrasensitive video tubes which utilize impact ionization of drifting holes. Both electrons and holes can drift in stabilized a‐Se, which is a distinct advantage since X‐ray photogeneration of charge carriers occurs throughout the bulk of the photoconductive layer. An a‐Se photoconductor has to be… 
Recent Developments of Amorphous Selenium-Based X-Ray Detectors: A Review
Amorphous selenium (a-Se) is a photoconductive material that has been intensively investigated from its early application in xerography to its present application in flat panel X-ray imagers. It can
An experimental and theoretical study of the dark current and x-ray sensitivity of amorphous selenium x-ray photoconductors
Recently, the world of diagnostic radiography has seen the integration of digital flat panel x-ray image detectors into x-ray imaging systems, replacing analog film screens. These flat panel x-ray
Imaging and Detection
Excellent X-ray detection properties and the unique nature of avalanche breakdown observed in amorphous selenium (a-Se) have enabled its use for several important applications such as in flat panel
Columnar recombination for X-ray generated electron-holes in amorphous selenium and its significance in a-Se x-ray detectors
Although amorphous selenium (a-Se) has a long and successful history of application in optical and X-ray imaging, some of its fundamental properties are still puzzling. In particularly, the mechanism
Effects of x-ray irradiation on charge transport and charge collection efficiency in stabilized a-Se photoconductors
Stabilized amorphous selenium (a-Se) photoconductive layers are currently used in the majority of modern digital x-ray flat panel imaging detectors in mammography. We examine the effects of
Amorphous selenium (a-Se) avalanche photodetector for applications in positron emission tomography (PET)
Although avalanche amorphous selenium (a-Se) is a very promising photoconductor for a variety of imaging applications, it is currently restricted to applications with electron beam readout. This is
Recent Progress in the Development of a-Se/CMOS Sensors for X-ray Detection
Amorphous selenium (a-Se) is a glass-former capable of deposition at high rates by thermal evaporation over a large area. It was chosen as a direct conversion material due to its appealing properties
Dark current mechanisms in stabilized amorphous selenium based n-i detectors for x-ray imaging applications
The dark current behavior under operating bias is one of the important selection criteria for an x-ray photoconductor to be usable in a practical x-ray image detector. The authors have developed an
Amorphous selenium ( aSe ) avalanche photodetector for applications in Positron Emission Tomography ( PET )
  • Physics
  • 2012
Although avalanche amorphous selenium (a-Se) is a very promising photoconductor for a variety of imaging applications, it is currently restricted to applications with electron beam readout. This is
Engineering of a Blocking Layer Structure for Low-Lag Operation of the a-PbO-Based X-Ray Detector
Direct conversion flat panel detectors are of great significance to the field of medical X-ray imaging since they offer imaging performance and diagnostic capabilities not achievable with other


Dark current in multilayer stabilized amorphous selenium X-ray photoconductors
Commercially available flat panel, direct conversion, digital X-ray image detectors use a photoconductive layer of stabilized amorphous selenium (a-Se) sandwiched between two electrodes to convert
X-ray sensitivity of photoconductors: application to stabilized a-Se
The x-ray sensitivity of a high-resistivity photoconductor sandwiched between two parallel plate electrodes and operating under a constant field is analysed by considering charge carrier generation
X-ray imaging using amorphous selenium: feasibility of a flat panel self-scanned detector for digital radiology.
The results showed that the flat-panel detector for digital radiology can potentially satisfy the detector design requirements for radiography (e.g., chest radiography and mammography) and is not quantum noise limited below the mean exposure rate typically used in fluoroscopy.
New digital detector for projection radiography
The operational principle of a new, patented digital radiographic system using a multi-layer structure consisting of a thin-film pixel array, selenium x-ray photoconductor, dielectric layer and top
Dark current in multilayer amorphous selenium x-ray imaging detectors
A theoretical model for describing the bias-dependent transient behavior of dark current in multilayer (n-i-p) amorphous selenium (a-Se) detectors has been developed. The transient dark currents in
DQE of photoconductive x-ray image detectors: application to a-Se
A cascaded linear system model that includes incomplete charge collection and interaction-depth dependent conversion gain and charge collection stages is considered for the calculation of the zero
A prototype amorphous selenium imaging plate system for digital radiography.
The clinical evaluation consists of preliminary images of a 16-kg female dog and a 4.5-kg rabbit and comparisons to film-screen images are offered, and detective quantum efficiency values of approximately 5% have been measured.
Digital radiology using active matrix readout of amorphous selenium: construction and evaluation of a prototype real-time detector.
The goal of the present work is to develop a large area, flat-panel solid-state detector for both digital radiography and fluoroscopy. The proposed detector employs a photoconductive layer of
Electrostatic imaging in radiology: limitations and prospects
  • J. Boag
  • Physics
    Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
  • 1979
In this radiographic technique, the latent image takes the form of a surface distribution of electric charge which may be rendered visible in various ways. The charge distribution is formed either on