Thin-Film Quantum Dot Photodiode for Monolithic Infrared Image Sensors

Sensors

Piet De Moor¹  Ioanna Vamvaka¹  Fortunato Frazzica¹  Epimitheas Georgitzikis¹  Jan Van Olmen¹  Paul Heremans¹  David Cheyns¹  Pawel E. Malinowski¹  Jorick Maes²  Zeger Hens² 

[1] IMEC, Kapeldreef 75, B-3001 Leuven, Belgium;Physics and Chemistry of Nanostructures, Ghent University, Krijgslaan 281-S3, B-9000 Ghent, Belgium;

关键词: infrared;    imaging;    image sensor;    quantum dot;    PbS;    monolithic integration;   

DOI  :  10.3390/s17122867

来源: DOAJ

【 摘 要 】

Imaging in the infrared wavelength range has been fundamental in scientific, military and surveillance applications. Currently, it is a crucial enabler of new industries such as autonomous mobility (for obstacle detection), augmented reality (for eye tracking) and biometrics. Ubiquitous deployment of infrared cameras (on a scale similar to visible cameras) is however prevented by high manufacturing cost and low resolution related to the need of using image sensors based on flip-chip hybridization. One way to enable monolithic integration is by replacing expensive, small-scale III–V-based detector chips with narrow bandgap thin-films compatible with 8- and 12-inch full-wafer processing. 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.

【 授权许可】

Unknown