Oct 8, 2009
Korean team explores memory property of SWNT networks
Many nanoelectronic devices have been realized with carbon nanotubes (CNTs) including field-effect transistors (FET), hybrid devices and complementary logic circuits. Thanks to their miniature dimensions, CNTs are a promising candidate for nanoscale memory cells that pave the way for high-density memory arrays. Difficulties concerning the alignment of individual carbon nanotubes with electrodes can be sidestepped by using a random network.
A recent study, which was published in the journal Nanotechnology, explores the memory properties of random networks of single-walled nanotubes (SWNTs) that may be explained by the polarization of water molecules near the SiO2/SWNTs interface. The Korean team based its design on random networks of SWNTs on a transparent glass substrate, which showed a gate voltage dependency and pulse time dependency much like those observed for a non-volatile memory device.
The group's model may provide an important insight into the distinctive mechanism behind the behaviour of memory devices based on random networks of SWNTs fabricated on a glass substrate. However, the research also highlights several essential problems that require attention, namely control over the number of SWNTs, the weak temperature effect related to the retention characteristics of the assembly (charge detrapping at a low temperature), and the stability of the device.
About the authors
The work was performed at Yonsei University of Korea and supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korean government (MOST). Keun Woo Lee is a PhD student studying at the School of Electrical & Electronic Engineering, Yonsei University and a leader of the Nano Device Research Group at the Electronic Device Lab. He is also a Senior Research Engineer at Hynix Semiconductor, Inc. Kon Yi Heo and Kyung Min Kim are Master's students also studying at the School of Electrical & Electronic Engineering at Yonsei University. They are members of the Nano Device Research Group at the Electronic Device Lab. Hyun Jae Kim is a professor in the School of Electrical & Electronic Engineering at Yonsei University and an academic adviser to the Nano Device Research Group at the Electronic Device Lab. He is a General Secretary of KIDS (Korean Information Display Society) and on the Program Committee of SID (Society of Information Display).