Photodiode and other sensor structures in flat-panel x-ray imagers and method for improving topological uniformity of the photodiode and other sensor structures in flat-panel x-ray imagers based on thin-film electronics

Abstract

A radiation sensor including a scintillation layer configured to emit photons upon interaction with ionizing radiation and a photodetector including in order a first electrode, a photosensitive layer, and a photon-transmissive second electrode disposed in proximity to the scintillation layer. The photosensitive layer is configured to generate electron-hole pairs upon interaction with a part of the photons. The radiation sensor includes pixel circuitry electrically connected to the first electrode and configured to measure an imaging signal indicative of the electron-hole pairs generated in the photosensitive layer and a planarization layer disposed on the pixel circuitry between the first electrode and the pixel circuitry such that the first electrode is above a plane including the pixel circuitry. A surface of at least one of the first electrode and the second electrode at least partially overlaps the pixel circuitry and has a surface inflection above features of the pixel circuitry. The surface inflection has a radius of curvature greater than one half micron.

1 . A radiation sensor comprising:
 a scintillation layer configured to emit photons upon interaction with ionizing radiation;   a photodetector including in order a first electrode, a photosensitive layer, and a photon-transmissive second electrode disposed in proximity to the scintillation layer;   said photosensitive layer configured to generate electron-hole pairs upon interaction with a part of said photons;   pixel circuitry electrically connected to the first electrode and configured to measure an imaging signal indicative of said electron-hole pairs generated in the photosensitive layer;   a planarization layer disposed on the pixel circuitry between the first electrode and the pixel circuitry such that the first electrode is above a plane including the pixel circuitry; and   a surface of at least one of said first electrode and said second electrode at least partially overlapping the pixel circuitry and having a surface inflection above features of the pixel circuitry.