npj Flexible Electronics (Sep 2020)

Curved digital X-ray detectors

  • Albert J.J.M. van Breemen,
  • Matthias Simon,
  • Olivier Tousignant,
  • Santhosh Shanmugam,
  • Jan-Laurens van der Steen,
  • Hylke B. Akkerman,
  • Auke Kronemeijer,
  • Walter Ruetten,
  • Rob Raaijmakers,
  • Lex Alving,
  • Jan Jacobs,
  • Pawel E. Malinowski,
  • Florian De Roose,
  • Gerwin H. Gelinck

DOI
https://doi.org/10.1038/s41528-020-00084-7
Journal volume & issue
Vol. 4, no. 1
pp. 1 – 8

Abstract

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Abstract A curved image sensor on plastic foil has been developed for cone beam computed tomography (CBCT) X-ray imaging. The image sensor of about 6 × 8 cm2 size has been built on a thin polyimide foil with an indium gallium zinc oxide (IGZO) backplane and an organic photodetectors (OPD) frontplane. A flexible cesium iodide (CsI) scintillator has been attached to the optical sensor with 480 × 640 pixels of 126 µm size. Dark current density of the OPD was low with less than 10−7 mA/cm2 at −2 V, while an external quantum efficiency (EQE) of about 50% was reached in the visible wavelength range matched to the scintillator output. The image quality of the digital X-ray detector allowed for 3D reconstruction images of a bone phantom on a rotating stage with a lab setup. The curved detector with 32 cm curvature radius opens up the path for very compact CBCT gantries with largely reduced footprint.