POS5-1255
Centrifugation-Controlled Semiconducting SWNT Separation for Purity-Dependent Field-Effect Transistor Performance
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
DongHyun Song (Kongju National University)
Co-Author(s)
Abstract
Single-walled carbon nanotubes (SWNT) are one-dimensional nanomaterials with excellent electrical transport properties, making them highly attractive for field-effect transistor (FET) applications. Semiconducting single-walled carbon nanotubes (s-SWNTs) can be used as solution-processable materials, flexible device structures, and large-area coating processes. In FET device, the channel material(s-SWNT) plays a critical role in controlling the current flow between the source and drain electrodes under an applied gate voltage. Therefore, the electrical quality and semiconducting purity of the SWNT network directly affect device parameters such as mobility, and on/off current ratio.
Raw SWNTs generally contain a mixture of metallic and semiconducting nanotubes. For FET, the presence of metallic SWNTs is undesirable. Because they can form continuous conductive pathways in the channel, resulting in high off-current and poor switching current. Therefore, extraction of semiconducting SWNTs is a critical step for obtaining high-performance SWNT-based FETs. In this study, conjugated polymer extraction (CPE) is used to selectively disperse s-SWNTs from SWNT.
In the CPE process, centrifugation RPM was controlled to obtain s-SWNT dispersions with different semiconducting purities. As the centrifugation RPM increased, metallic SWNTs, bundles, and large aggregates were more effectively removed, resulting in improved s-SWNT purity. The fabricated s-SWNT FETs exhibited a mobility of approximately 20 cm² V⁻¹ s⁻¹ and an on/off current ratio of about 10⁴ under optimized conditions. These results suggest that FET characteristics, especially the on/off ratio, can provide a more practical evaluation of s-SWNT purity, while UV-Vis analysis alone may not fully reflect the effect of residual metallic nanotubes on device performance.
Raw SWNTs generally contain a mixture of metallic and semiconducting nanotubes. For FET, the presence of metallic SWNTs is undesirable. Because they can form continuous conductive pathways in the channel, resulting in high off-current and poor switching current. Therefore, extraction of semiconducting SWNTs is a critical step for obtaining high-performance SWNT-based FETs. In this study, conjugated polymer extraction (CPE) is used to selectively disperse s-SWNTs from SWNT.
In the CPE process, centrifugation RPM was controlled to obtain s-SWNT dispersions with different semiconducting purities. As the centrifugation RPM increased, metallic SWNTs, bundles, and large aggregates were more effectively removed, resulting in improved s-SWNT purity. The fabricated s-SWNT FETs exhibited a mobility of approximately 20 cm² V⁻¹ s⁻¹ and an on/off current ratio of about 10⁴ under optimized conditions. These results suggest that FET characteristics, especially the on/off ratio, can provide a more practical evaluation of s-SWNT purity, while UV-Vis analysis alone may not fully reflect the effect of residual metallic nanotubes on device performance.
