title: Multilevel non-volatile data storage utilizing common current hysteresis of networked single walled carbon nanotubes.
abstract: The characteristic source-drain current hysteresis frequently observed in field-effect transistors with networked single walled carbon-nanotube (NSWNT) channels is problematic for the reliable switching and sensing performance of devices. But the two distinct current states of the hysteresis curve at a zero gate voltage can be useful for memory applications. In this work, we demonstrate a novel non-volatile transistor memory with solution-processed NSWNTs which are suitable for multilevel data programming and reading. A polymer passivation layer with a small amount of water employed on the top of the NSWNT channel serves as an efficient gate voltage dependent charge trapping and de-trapping site. A systematic investigation evidences that the water mixed in a polymer passivation solution is critical for reliable non-volatile memory operation. The optimized device is air-stable and temperature-resistive up to 80 °C and exhibits excellent non-volatile memory performance with an on/off current ratio greater than 10(4), a switching time less than 100 ms, data retention longer than 4000 s, and write/read endurance over 100 cycles. Furthermore, the gate voltage dependent charge injection mediated by water in the passivation layer allowed for multilevel operation of our memory in which 4 distinct current states were programmed repetitively and preserved over a long time period.
authors.affiliation: Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, Republic of Korea. cmpark@yonsei.ac.kr.
authors.forename: Ihn
authors.initials: I
authors.lastname: Hwang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Sun Kak
authors.initials: SK
authors.lastname: Hwang
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Cho
authors.forename: Kang Lib
authors.initials: KL
authors.lastname: Kim
authors.forename: Beomjin
authors.initials: B
authors.lastname: Jeong
authors.forename: June
authors.initials: J
authors.lastname: Huh
authors.forename: Cheolmin
authors.initials: C
authors.lastname: Park