Organic nonvolatile memory transistors with self-doped polymer energy well structures

Abstract

Developing organic nonvolatile memory devices with a writing/reading/erasing logic function in actual array structures is extremely important for realizing low-cost lightweight/flexible plastic electronic systems. Here, we demonstrate that organic field-effect transistors (OFETs) with a polymer energy well structure (PEW-OFET) exhibit excellent nonvolatile memory performances. The PEW structure is created by sandwiching a self-doped poly(o-anthranilic acid) (SD-PARA) nanolayer (high dielectric constant, k = 14) between two low-dielectric polymer layers (k = 2-4). The primary idea behind this concept is the rapid storage and retrieval of charge carriers in the PEW layer during operation due to the high k feature of the SD-PARA nanolayer, which aids the rapid transport of charge carriers inside, whereas the stored charges are safely trapped due to the two low k layers. The results indicate that the PEW-OFET memory devices exhibit outstanding retention characteristics upon continuous reading up to 2000 s after writing, whereas their excellent writing/reading/erasing/reading cyclability is demonstrated in a test with 43000 cycles. Therefore, the present simple yet cost-effective PEW-OFET concept is expected to significantly contribute to the development of low-cost plastic memory array devices because all processes can be inexpensively performed at low temperatures and additional logic transistors are unnecessary. NPG Asia Materials (2013) 5, e33; doi: 10.1038/am.2012.62; published online 18 January 2013