Imagers that operate in the near-infrared region (wavelengths of 0.7–1.4 µm) are of use in applications such as material sorting, machine vision and autonomous driving. However, such imagers typically use the flip-chip method to connect infrared photodiodes with silicon-based readout integrated circuits, as the need for high-temperature processing and single-crystalline substrates prevents direct integration. This increases processing complexity and cost. Here we report high-resolution imagers that monolithically integrate near-infrared colloidal quantum dot photodiodes with complementary metal–oxide–semiconductor readout integrated circuits. The colloidal quantum dot photodetector is designed with a structure compatible with complementary metal–oxide–semiconductors and exhibits a spectral range of 400–1,300 nm, room-temperature detectivity of 2.1 × 1012 Jones, −3 dB bandwidth of 140 kHz and linear dynamic range of over 100 dB. With this approach, we create a large (640 × 512 pixels) imager that exhibits a spatial resolution of 40 line pairs per millimetre at a modulation transfer function of 50%, and we show that it can be used for vein imaging and matter identification.
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Chen, Y., Chao, K. & Kim, M. S. Machine vision technology for agricultural applications. Comput. Electron. Agr. 36, 173–191 (2002).
Saran, R. & Curry, R. J. Lead sulphide nanocrystal photodetector technologies. Nat. Photon. 10, 81–92 (2016).
Konstantatos, G. & Sargent, E. H. Nanostructured materials for photon detection. Nat. Nanotechnol. 5, 391–400 (2010).
Rogalski, A., Antoszewski, J. & Faraone, L. Third-generation infrared photodetector arrays. J. Appl. Phys. 105, 091101 (2009).
Lu, H., Carroll, G. M., Neale, N. R. & Beard, M. C. Infrared quantum dots: progress, challenges, and opportunities. ACS Nano 13, 939–953 (2019).
Livache, C., Martinez, B., Goubet, N., Ramade, J. & Lhuillier, E. Road map for nanocrystal based infrared photodetectors. Front. Chem. 6, 575 (2018).
Otani, Y. Snapshot full Stokes imager by polarization cameras and its application to bio-imaging. In Proc. SPIE 11709 Ultra-High-Definition Imaging Systems IV 1170904 (SPIE, 2021).https://doi.org/10.1117/12.2587339
Lei, W., Antoszewski, J. & Faraone, L. Progress, challenges, and opportunities for HgCdTe infrared materials and detectors. Appl. Phys. Rev. 2, 041303 (2015).
Kinch, M. A. The rationale for ultra-small pitch IR systems. In Proc. SPIE 9070 Infrared Technology and Applications XL 907032 (SPIE, 2014).
Rogalski, A. Infrared Detectors (CRC Press, 2010).
Manda, S. et al. High-definition visible-SWIR InGaAs image sensor using Cu-Cu bonding of III-V to silicon wafer. In 2019 IEEE International Electron Devices Meeting 16.7.1–16.7.4 (IEEE, 2019).
Jean, J. et al. Synthesis cost dictates the commercial viability of lead sulfide and perovskite quantum dot photovoltaics. Energy Environ. Sci. 11, 2295–2305 (2018).
Chen, W. et al. Spray-deposited PbS colloidal quantum dot solid for near-infrared photodetectors. Nano Energy 78, 105254 (2020).
Klem, E. J. D., Gregory, C., Temple, D. & Lewis, J. PbS colloidal quantum dot photodiodes for low-cost SWIR sensing. In Proc. SPIE 9451 Infrared Technology and Applications XL 907032 (SPIE, 2015).
Rauch, T. et al. Near-infrared imaging with quantum-dot-sensitized organic photodiodes. Nat. Photon. 3, 332–336 (2009).
Goossens, S. et al. Broadband image sensor array based on graphene–CMOS integration. Nat. Photon. 11, 366–371 (2017).
Barrow, L. et al. A QuantumFilm based quadVGA 1.5 µm pixel image sensor with over 40% QE at 940 nm for actively illuminated applications. IISW Dig. Tech. Pap. 378–381 (2017).
SWIR Vision Systems. Acuros CQD 192/1920L GigE SWIR Camera (accessed 1 March 2021); http://www.swirvisionsystems.com/wp-content/uploads/Acuros-CQD-1920L-GigE-SWIR-Camera_003.pdf
Georgitzikis, E. et al. Organic- and QD-based image sensors integrated on 0.13 μm CMOS ROIC for high resolution, multispectral infrared imaging. Proc. IISW (2019).
Lee, J. et al. Imaging in short-wave infrared with 1.82 μm pixel pitch quantum dot image sensor. In IEEE International Electron Devices Meeting 16.5.1–16.5.4 (IEEE, 2020).
Pejović, V. et al. Infrared colloidal quantum dot image sensors. IEEE Trans. Electron Devices 69, 2840–2850 (2021).
Pejovic, V. et al. Thin-film photodetector optimization for high-performance short-wavelength infrared imaging. IEEE Electron Device Lett. 42, 1196–1199 (2021).
Pal, B. N. et al. High-sensitivity p–n junction photodiodes based on PbS nanocrystal quantum dots. Adv. Funct. Mater. 22, 1741–1748 (2012).
Sliz, R. et al. Stable colloidal quantum dot inks enable inkjet-printed high-sensitivity infrared photodetectors. ACS Nano 13, 11988–11995 (2019).
Manders, J. R. et al. Low-noise multispectral photodetectors made from all solution-processed inorganic semiconductors. Adv. Funct. Mater. 24, 7205–7210 (2014).
Zhang, J. et al. Preparation of Cd/Pb chalcogenide heterostructured Janus particles via controllable cation exchange. ACS Nano 9, 7151–7163 (2015).
Zhang, C. et al. Combination of cation exchange and quantized Ostwald ripening for controlling size distribution of lead chalcogenide quantum dots. Chem. Mater. 29, 3615–3622 (2017).
Heath, J. T., Cohen, J. D. & Shafarman, W. N. Bulk and metastable defects in CuIn1−xGaxSe2 thin films using drive-level capacitance profiling. J. Appl. Phys. 95, 1000–1010 (2004).
Artegiani, E. et al. Analysis of a novel CuCl2 back contact process for improved stability in CdTe solar cells. Prog. Photovolt. 27, 706–715 (2019).
Ni, Z. et al. Resolving spatial and energetic distributions of trap states in metal halide perovskite solar cells. Science 367, 1352–1358 (2020).
Wang, R. et al. Highly efficient inverted structural quantum dot solar cells. Adv. Mater. 30, 1704882 (2018).
Fuentes-Hernandez, C. et al. Large-area low-noise flexible organic photodiodes for detecting faint visible light. Science 370, 698–701 (2020).
Cong, H. et al. High-speed waveguide-integrated Ge/Si avalanche photodetector. Chinese Phys. B 25, 058503 (2016).
Chow, W. W., Vawter, G. A. & Junpeng, G. Approaching intraband relaxation rates in the high-speed modulation of semiconductor lasers. IEEE J. Quantum Electron. 40, 989–995 (2004).
Geremew, A. et al. Low-frequency electronic noise in superlattice and random-packed thin films of colloidal quantum dots. Nanoscale 11, 20171–20178 (2019).
Liu, H., Lhuillier, E. & Guyot-Sionnest, P. 1/f noise in semiconductor and metal nanocrystal solids. J. Appl. Phys. 115, 154309 (2014).
Carey, G. H., Levina, L., Comin, R., Voznyy, O. & Sargent, E. H. Record charge carrier diffusion length in colloidal quantum dot solids via mutual dot-to-dot surface passivation. Adv. Mater. 27, 3325–3330 (2015).
Zhitomirsky, D. et al. Engineering colloidal quantum dot solids within and beyond the mobility-invariant regime. Nat. Commun. 5, 3803 (2014).
Appendix I: scene-referenced SNR and dynamic range (Imatest, 2021); https://www.imatest.com/docs/noise/
Teraphongphom, N., Kong, C. S., Warram, J. M. & Rosenthal, E. L. Specimen mapping in head and neck cancer using fluorescence imaging. Laryngoscope 2, 447–452 (2017).
Hamamatsu. InGaAs camera C10633-13-23 (Hamamatsu, 2013); https://www.hamamatsu.com/jp/en/product/type/C14041-10U/index.html
Baek, S. W. et al. Efficient hybrid colloidal quantum dot/organic solar cells mediated by near-infrared sensitizing small molecules. Nat. Energy 4, 969–976 (2019).
Tavakoli, M. M. et al. Efficient, flexible, and ultra-lightweight inverted PbS quantum dots solar cells on all-CVD-growth of parylene/graphene/oCVD PEDOT substrate with high power-per-weight. Adv. Mater. Inter. 7, 2000498 (2020).
Lee, J. W., Kim, D. Y. & So, F. Unraveling the gain mechanism in high performance solution-processed PbS infrared PIN photodiodes. Adv. Funct. Mater. 25, 1233–1238 (2015).
Dong, R. et al. An ultraviolet-to-NIR broad spectral nanocomposite photodetector with gain. Adv. Opt. Mater. 2, 549–554 (2014).
Yoo, J., Jeong, S., Kim, S. & Je, J. H. A stretchable nanowire UV-vis-NIR photodetector with high performance. Adv. Mater. 27, 1712–1717 (2015).
Wei, Y. et al. Hybrid organic/PbS quantum dot bilayer photodetector with low dark current and high detectivity. Adv. Funct. Mater. 28, 1706690 (2018).
Qiao, K. K. et al. Efficient interface and bulk passivation of PbS quantum dot infrared photodetectors by PbI2 incorporation. RSC Adv. 7, 52947–52954 (2017).
Clifford, J. P. et al. Fast, sensitive and spectrally tuneable colloidal-quantum-dot photodetectors. Nat. Nanotechnol. 4, 40–44 (2009).
This work was financially supported by the National Key Research and Development Program of China (2021YFA0715500; J.T.), National Natural Science Foundation of China (61725401; J.T. and 61904065; L.G.) and Fund for Innovative Research Groups of the Natural Science Foundation of Hubei Province (2020CFA034; J.T.). We thank the Analytical and Testing Center of HUST and the facility support of the Center for Nanoscale Characterization and Devices (CHCB), WNLO-HUST. We appreciate helpful discussions from Hao Li and Prof. Dongsheng Liu.
The authors declare no competing interests.
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Liu, J., Liu, P., Chen, D. et al. A near-infrared colloidal quantum dot imager with monolithically integrated readout circuitry. Nat Electron (2022). https://doi.org/10.1038/s41928-022-00779-x