High performance nonvolatile transistor memories of pentacene using the electrets of star-branched p-type polymers and their donor-acceptor blends
Journal
Journal of Materials Chemistry C
Journal Volume
2
Journal Issue
8
Pages
1436-1446
Date Issued
2014
Author(s)
Abstract
Pentacene-based nonvolatile field-effect transistor (FET) memory utilizing novel electrets consisting of star-branched p-type polymers, polystyrene para-substituted oligofluorenes (P(StFl)n), and their hybrids with n-type PCBM was demonstrated in this work. As the arm number of P(StFl)n increases, the OFET hole mobility and memory window are improved to 0.69 cm2 V?1 s?1 and 19.75 V, with a high ON/OFF current ratio of over 108. The low dielectric constant of the large arm number of P(StFl)n leads to the greater loaded electric field and results in a large memory window. Moreover, the device performance can be further improved when the p-type star-branched (P(StFl)n) based electrets are blended with n-type PCBM. By precisely controlling the blended concentration of PCBM, the hole mobility of pentacene and the derived memory window could increase to 1.04 cm2 V?1 s?1 and 35.59 V, respectively. Two kinds of mechanism are proposed for P(StFl)n and PCBM:P(StFl)4 based memories, including carrier trapping and tunneling effect under a gate electric field. Our results not only show the potential of the star-branched polymers serving as electrets for FET memory, but also demonstrate the use of donor�Vacceptor (D�VA) hybrid electrets is an efficient strategy to achieve high-performance nonvolatile OFET memories.
SDGs
Type
journal article