The DEPFET Sensor-Amplifier Structure: A Method to Beat 1/f Noise and Reach Sub-Electron Noise in Pixel Detectors

• Main Authors: Gerhard Lutz, Matteo Porro, Stefan Aschauer, Stefan Wölfel, Lothar Strüder
• Format: Article
• Language: English
• Published: MDPI AG 2016-04-01
• Series: Sensors
• Subjects: DEPFET; photon detection; sub-electron precision; charge measurement; pixel detector; X-ray spectroscopy
• Online Access: http://www.mdpi.com/1424-8220/16/5/608

Depleted field effect transistors (DEPFET) are used to achieve very low noise signal charge readout with sub-electron measurement precision. This is accomplished by repeatedly reading an identical charge, thereby suppressing not only the white serial noise but also the usually constant 1/f noise. The repetitive non-destructive readout (RNDR) DEPFET is an ideal central element for an active pixel sensor (APS) pixel. The theory has been derived thoroughly and results have been verified on RNDR-DEPFET prototypes. A charge measurement precision of 0.18 electrons has been achieved. The device is well-suited for spectroscopic X-ray imaging and for optical photon counting in pixel sensors, even at high photon numbers in the same cell.