Imec Quantum Dot Sensor

MDPI Special Issue on the 2017 International Image Sensor Workshop (IISW) publishes Imec, KU Leuven, and Ghent University paper "Thin-Film Quantum Dot Photodiode for Monolithic Infrared Image Sensors" by Pawel E. Malinowski, Epimitheas Georgitzikis, Jorick Maes, Ioanna Vamvaka, Fortunato Frazzica, Jan Van Olmen, Piet De Moor, Paul Heremans, Zeger Hens, and David Cheyns. The paper describes a somewhat similar to Invisage IR image sensor:

"This work describes a CMOS-compatible pixel stack based on lead sulfide quantum dots (PbS QD) with tunable absorption peak. Photodiode with a 150-nm thick absorber in an inverted architecture shows dark current of 10−6 A/cm2 at −2 V reverse bias and EQE above 20% at 1440 nm wavelength. Optical modeling for top illumination architecture can improve the contact transparency to 70%. Additional cooling (193 K) can improve the sensitivity to 60 dB. This stack can be integrated on a CMOS ROIC, enabling order-of-magnitude cost reduction for infrared sensors."