Integrated scintillator grid with photodiodes

A method of fabricating an X-ray imaging system, comprising:

• forming an array of photodiodes, which are electrically isolated from each other, in a device layer on a first side of a silicon wafer;
• forming an array of grid holes on a second side of the silicon wafer opposite the first side thereof, each grid hole of the array of grid holes aligned with a respective photodiode of the array of photodiodes;
• disposing a layer of scintillating material over the array of grid holes on the second side of the silicon wafer;
• disposing a layer of reflective material on the layer of scintillating, material;
• forming an array of sensing circuits such that each sensing circuit of the array of sensing circuits is configured to sense an electrical signal in a respective photodiode of the array of photodiodes corresponding to electron-hole pairs in the respective photodiode caused by light absorbed by the respective photodiode;
• bonding the array of sensing circuits to the array of photodiodes on the first side of the silicon wafer such that each sensing circuit of the array of sensing circuits is electrically connected to the respective photodiode;
• and
• filling, the grid holes with a filler material,
• wherein the filler material comprises a transparent solid material.