Flexible non-volatile optical memory thin-film transistor device with over 256 distinct levels based on an organic bicomponent blend


Organic nanomaterials are attracting a great deal of interest for use in flexible electronic applications such as logic circuits, displays and solar cells. These technologies have already demonstrated good performances, but flexible organic memories are yet to deliver on all their promise in terms of volatility, operational voltage, write/erase speed, as well as the number of distinct attainable levels. Here, we report a multilevel non-volatile flexible optical memory thin-film transistor based on a blend of a reference polymer semiconductor, namely poly(3-hexylthiophene), and a photochromic diarylethene, switched with ultraviolet and green light irradiation. A three-terminal device featuring over 256 (8 bit storage) distinct current levels was fabricated, the memory states of which could be switched with 3 ns laser pulses. We also report robustness over 70 write–erase cycles and non-volatility exceeding 500 days. The device was implemented on a flexible polyethylene terephthalate substrate, validating the concept for integration into wearable electronics and smart nanodevices.

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Figure 1: Electrical characterization of the bottom-gate/bottom-contact P3HT/DAE-Me devices.
Figure 2: Data retention of the memory device.
Figure 3: IDS–time curves (corrected for bias stress) with irradiation of the device with 3 ns laser pulses (313 nm) every 10 s, underlining the ability to behave as a multilevel memory.
Figure 4: Integration of the memory unit onto a flexible PET substrate.


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This work was supported financially by the EC through the MSCA-ITN project iSwitch (GA no. 642196) as well as ERC projects SUPRAFUNCTION (GA-257305) and LIGHT4FUNCTION (GA-308117), the Agence Nationale de la Recherche through the LabEx CSC (ANR-10-LABX-0026_CSC), the International Center for Frontier Research in Chemistry (icFRC) and the German Research Foundation (via SFB 658).

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P.S. and E.O. conceived the experiment and designed the study. M.H. and S.H. designed the DAEs and carried out their synthesis and electrochemical characterization. T.L., E.O., G.B. and E.P. designed and performed the time-response measurements. E.O. designed and T.L. performed the device experiments. T.L., E.O. and P.S. co-wrote the paper. All authors discussed the results and contributed to the interpretation of data, as well as contributing to editing the manuscript.

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Correspondence to Stefan Hecht or Emanuele Orgiu or Paolo Samorì.

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The authors declare no competing financial interests.

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Leydecker, T., Herder, M., Pavlica, E. et al. Flexible non-volatile optical memory thin-film transistor device with over 256 distinct levels based on an organic bicomponent blend. Nature Nanotech 11, 769–775 (2016). https://doi.org/10.1038/nnano.2016.87

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