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A polymer/semiconductor write-once read-many-times memory


Organic devices promise to revolutionize the extent of, and access to, electronics by providing extremely inexpensive, lightweight and capable ubiquitous components that are printed onto plastic, glass or metal foils1,2,3. One key component of an electronic circuit that has thus far received surprisingly little attention is an organic electronic memory. Here we report an architecture for a write-once read-many-times (WORM) memory, based on the hybrid integration of an electrochromic polymer with a thin-film silicon diode deposited onto a flexible metal foil substrate. WORM memories are desirable for ultralow-cost permanent storage of digital images, eliminating the need for slow, bulky and expensive mechanical drives used in conventional magnetic and optical memories. Our results indicate that the hybrid organic/inorganic memory device is a reliable means for achieving rapid, large-scale archival data storage. The WORM memory pixel exploits a mechanism of current-controlled, thermally activated un-doping of a two-component electrochromic conducting polymer.

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Figure 1: Generalized architecture of the WORM memory, and the materials used in its implementation.
Figure 2: The switching characteristics of the WORM memory pixel.
Figure 3: The switching process of the WORM memory pixel is shown under several different writing conditions.
Figure 4: The behaviour of the WORM memory element under transient voltage pulse conditions.


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We thank A. Elschner and H. C. Starck for samples of Baytron P, and M. Thompson for discussions. We also thank National Renewable Energy Laboratories for supplying the thin-film Si diodes. This work was supported by HP and the National Science Foundation.

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Correspondence to Stephen R. Forrest.

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Möller, S., Perlov, C., Jackson, W. et al. A polymer/semiconductor write-once read-many-times memory. Nature 426, 166–169 (2003).

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