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High-gain infrared-to-visible upconversion light-emitting phototransistors


Infrared-to-visible upconversion devices made by integrating an infrared quantum dot photodetector with an organic light-emitting diode potentially offer a route to low-cost, pixel-free infrared imaging. However, making such devices sufficiently efficient for practical use is a challenge. Here, we report a high-gain vertical phototransistor with a perforated metallic source electrode having an EQE up to 1 × 105% and a detectivity of 1.2 × 1013 Jones. By incorporating a phosphorescent organic light-emitting diode in this phototransistor, an infrared-to-visible upconversion LEPT with a photon-to-photon conversion efficiency of over 1,000% is demonstrated.

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Figure 1: Schematic diagram of the new upconversion device.
Figure 2: Operation mechanism of the vertical phototransistor.
Figure 3: Device characteristics of vertical phototransistor.
Figure 4: Device characteristics of the LEPT.

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  1. Chen, J. et al. Hybrid organic/inorganic optical up-converter for pixel-less near-infrared imaging. Adv. Mater. 24, 3138–3142 (2012).

    Article  ADS  Google Scholar 

  2. Allard, L., Liu, H., Buchanan, M. & Wasilewski, Z. Pixelless infrared imaging utilizing a p-type quantum well infrared photodetector integrated with a light emitting diode. Appl. Phys. Lett. 70, 2784–2786 (1997).

    Article  ADS  Google Scholar 

  3. Kim, D. Y., Song, D. W., Chopra, N., De Somer, P. & So, F. Organic infrared upconversion device. Adv. Mater. 22, 2260 (2010).

    Article  Google Scholar 

  4. Kim, D. Y. et al. PbSe nanocrystal-based infrared-to-visible up-conversion device. Nano. Lett. 11, 2109–2113 (2011).

    Article  ADS  Google Scholar 

  5. Kim, D. Y., Lai, T.-H., Lee, J. W., Manders, J. R. & So, F. Multi-spectral imaging with infrared sensitive organic light emitting diode. Sci. Rep. 4, 5946 (2014).

    Article  Google Scholar 

  6. Campbell, I. H. & Crone, B. K. A near infrared organic photodiode with gain at low bias voltage. Appl. Phys. Lett. 95, 263302 (2009).

    Article  ADS  Google Scholar 

  7. Koppens, F. et al. Photodetectors based on graphene, other two-dimensional materials and hybrid systems. Nature Nanotech. 9, 780–793 (2014).

    Article  ADS  Google Scholar 

  8. Sun, Z. et al. Infrared photodetectors based on CVD-grown graphene and PbS quantum dots with ultrahigh responsivity. Adv. Mater. 24, 5878–5883 (2012).

    Article  ADS  Google Scholar 

  9. Konstantatos, G. et al. Ultrasensitive solution-cast quantum dot photodetectors. Nature 442, 180–183 (2006).

    Article  ADS  Google Scholar 

  10. Konstantatos, G. et al. Hybrid graphene–quantum dot phototransistors with ultrahigh gain. Nature Nanotech. 7, 363–368 (2012).

    Article  ADS  Google Scholar 

  11. Peumans, P. & Forrest, S. R. Very-high-efficiency double-heterostructure copper phthalocyanine/C60 photovoltaic cells. Appl. Phys. Lett. 79, 126–128 (2001).

    Article  ADS  Google Scholar 

  12. Sze, S. M. & Ng, K. K. Physics of Semiconductor Devices (Wiley, 2006).

    Book  Google Scholar 

  13. Tang, J. A. & Sargent, E. H. Infrared colloidal quantum dots for photovoltaics: fundamentals and recent progress. Adv. Mater. 23, 12–29 (2011).

    Article  Google Scholar 

  14. Sargent, E. H. Infrared quantum dots. Adv. Mater. 17, 515–522 (2005).

    Article  Google Scholar 

  15. He, G. et al. High-efficiency and low-voltage p–i–n electrophosphorescent organic light-emitting diodes with double-emission layers. Appl. Phys. Lett. 85, 3911–3913 (2004).

    Article  ADS  Google Scholar 

  16. Lee, J. Y. & Kwon, J. H. The effect of C60 doping on the device performance of organic light-emitting diodes. Appl. Phys. Lett. 86, 063514 (2005).

    Article  ADS  Google Scholar 

  17. Krätschmer, W., Lamb, L. D., Fostiropoulos, K. & Huffman, D. R. C60: a new form of carbon. Nature 347, 354–358 (1990).

    Article  ADS  Google Scholar 

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The authors acknowledge financial support from Nanoholdings LLC. The experimental part of the work was carried out at the University of Florida.

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F.S. conceived the device concept. H.Y. fabricated the devices. H.Y., D.Y.K. and F.S. designed the experiments and analysed the data. J.H.L., S.J.B. and R.S. contributed to the development of the photoactive gate part in the vertical transistors. J.W.L. contributed to the detectivity measurements.

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Correspondence to Franky So.

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The authors declare no competing financial interests.

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Yu, H., Kim, D., Lee, J. et al. High-gain infrared-to-visible upconversion light-emitting phototransistors. Nature Photon 10, 129–134 (2016).

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