Cobalt Nano Particle Size Dependence of Noise Modulations in Relation to Nonlinearity

Abstract

Carbon nanotubes (CNTs) are low-dimensional materials, and their surface therefore affects several properties of CNTs. For example, CNT field effect transistors (CNTFETs) are well known as noisy devices caused by the adhesion of molecules on the surface. However, nonlinear systems sometimes have advantages in working with noise. Therefore, we combined the noise CNTFET and another transistor of CNT for a trial nonlinear system. The sine wave amplification in the transistor with noise was then measured. In this system, the control of noise is required for operation of the device and this might be common for nano-sized devices. We can control the noise properties of CNTFET through the control of the Co nano particles catalyst. Depending on fabrication conditions, the noise of a CNTFET has different noise intensity and gate voltage (Vg) dependence with 1/f type noise. Noise in CNTFETs grown on small Co particles can be controlled within the small |Vg|, and the control range for noise is wide. We studied the modification of nonlinearity using our trial nonlinear system. It was governed by the ratio of the signals and the noise, and shows the robustness of modification.

Carbon Nanowall Field Effect Transistors Using a Self-Aligned Growth Process

“…The semiconductive characteristics in CNW-FETs could be caused by Schottky contacts similar to that reported for CNT-FETs [36,37]. We know that defects and/or adsorbates have large effects on the electrical properties in CNTs [12,[38][39][40]. Therefore, the semiconductive characteristics for CNW-FETs might be caused by the defects induced in the CNW channels.…”

“…Recently, an aptamer-based novel biosensor has been developed that can be used for the label-free detection of IgE [9,10]. We have also developed noise-enhanced nonlinear devices [11,12] and demonstrated controllability of operations [13,14].…”

Raman spectral mapping of self-aligned carbon nanowalls

“…9,10) The room-temperature operation of single-electron transistors, which usually work only at low temperature, can be achieved using nanotechnology. 11,12) We have also developed noise-enhanced nonlinear devices [13][14][15] and demonstrated the controllability of device operations. 16,17) The control of CNT growth seems to be one of the important technologies 18) for the actual applications of CNTs.…”