Dot Single Electron Transistor Research Articles

Revolutionizing ECG interpretation with AI-powered universal smartphone technology

To connect digital and physical devices a highly connected global network is termed as Internet. The objective of internet is extended by Internet of Thing (IoT) by connecting devices from different domain. Millions of devices are used for information collection and communication in IoT. Integration of nanotechnology with IoT termed as Internet of Nano Things (IoNT) and plays an Important role in growth of compact devices. The requirement of feature and functionality in compact, handheld and battery operated devices increasing day by day. The battery life is an important factor for these devices. The battery life of these devices can be increased by reducing the power consumption. Single electron devices can play an important role in limiting the power consumption of these devices. In this paper a Si dot Single Electron Transistor is designed with nano scale channel length. Si dot is placed between gate and island to improve electrical properties of device. The characteristics of Si dot SET is compared with a SET without Si dot and capacitance is calculated for both the devices. It is found that device with Si dot possess higher charging energy so it is capable of room temperature operation. This paper also discusses the role of nano devices in IoNT as well as application areas and challenges of IoNT.

Si dot single electron transistor for Internet of nano things

To connect digital and physical devices a highly connected global network is termed as Internet. The objective of internet is extended by Internet of Thing (IoT) by connecting devices from different domain. Millions of devices are used for information collection and communication in IoT. Integration of nanotechnology with IoT termed as Internet of Nano Things (IoNT) and plays an Important role in growth of compact devices. The requirement of feature and functionality in compact, handheld and battery operated devices increasing day by day. The battery life is an important factor for these devices. The battery life of these devices can be increased by reducing the power consumption. Single electron devices can play an important role in limiting the power consumption of these devices. In this paper a Si dot Single Electron Transistor is designed with nano scale channel length. Si dot is placed between gate and island to improve electrical properties of device. The characteristics of Si dot SET is compared with a SET without Si dot and capacitance is calculated for both the devices. It is found that device with Si dot possess higher charging energy so it is capable of room temperature operation. This paper also discusses the role of nano devices in IoNT as well as application areas and challenges of IoNT.

Modeling and simulation of single electron transistor with master equation approach

In this paper, we discuss modeling and simulation of single dot Single Electron Transistor (SET) using master equation approximation. For SET modeling and simulation, master equation method treats the electron tunneling and its transition probabilistically. The probability of electron tunneling is used to determine the current density in accordance with selected input parameters. The calculation results show fairly accurate electrical characteristics of SET as compared with experimental data. Staircase pattern from I-V are clearly obtained as the main role of coulomb blockade effect in SET system. We also extend our calculation by introduce some additional parameters such as; the effect of working temperature, gate voltage dependent, and the influence of resistance to the device characteristic. We found that increasing operational temperature will promote higher current density, both in forward and reverse bias region. In the case of using single dot with 30 nm × 80 nm × 125 nm dimension, coulomb blockade effect could be reduced by applying gate voltage higher than 3V and setting drain resistance higher than source's. Our studies show an alternative approach in modeling and simulation of electronic devices and could be potential for development of novel nanoelectronic devices.

Cross-sectional transmission electron microscopy analysis of a single self-assembled quantum dot single electron transistor fabricated by atomic force microscope local oxidation

We show a cross-sectional transmission electron microscopy (TEM) analysis of a single electron transistor (SET) composed of a nanogap electrode fabricated by atomic force microscope (AFM) local oxidation and a single self-assembled quantum dot (QD). The detail structure of SET is analyzed by using both TEM and in-situ energy dispersive X-ray spectroscopy (EDX) measurement. It demonstrates that after AFM lithography, the QD in the SET maintained its high crystal quality and without notable damage or oxidation. Our findings demonstrate the good controllability and reliability of the AFM local oxidation method for fabricating nanogap electrode on a single QD.

AlGaAs/GaAs single electron transistor fabricated without modulation doping

We have fabricated a quantum dot single electron transistor, based on AlGaAs/GaAs heterojunction without modulation doping, which exhibits clear and stable Coulomb blockade oscillations. The temperature dependence of the Coulomb blockade peak line shape is well described by standard Coulomb blockade theory in the quantum regime. Bias spectroscopy measurements have allowed us to directly extract the charging energy, and showed clear evidence of excited state transport, confirming that individual quantum states in the dot can be resolved.

Role of defects in transport through a quantum dot single electron transistor

The effect of a single dotlike defect on the transport through a quantum dot single electron transistor weakly coupled to external leads is studied. It is found that the conductance profile is changed significantly by the quantum mechanical tunneling between the dot and the defect and the interactions between them, both of which are dependent on the distance between the dot and the defect, as also by the morphology of the defect. In particular, we find that even a very small strength of interdot interaction has a major influence on the transport and must be taken into account in device fabrication.

Vertical quantum dots at high magnetic fields beyond the few-electron limit

We describe phenomena that can be studied in vertical quantum dot single electron transistors. Moving from the few-electron to the several- and many-electron regimes, features in the conductance peaks initially related to spin polarization evolve with magnetic field. This allows us to first probe the spin-flip region beyond the last single-particle crossing at low field, and then the formation and stability of the spin-polarized maximum density droplet at high field. According to a simple capacitance model, charge redistribution in the dot at higher magnetic fields is accompanied by abrupt changes in the area of the droplet.

Fabrication and Characterization of GaAs Single Electron Devices Having Single and Multiple Dots Based on Schottky In-Plane-Gate and Wrap-Gate Control of Two-Dimensional Electron Gas

Single-dot and multiple (2, 3, 18, and 37)-dot single electron transistors (SETs) based on the control of a two-dimensional electron gas (2DEG) with a recently proposed Schottky in-plane gate (IPG) and a newly introduced Schottky wrap gate (WPG) were successfully fabricated on AlGaAs/GaAs wafers using electron beam (EB) lithography and their transport properties were investigated. Each of the fabricated SETs showed Coulomb blockade-like conductance oscillation. In single-dot SETs, a strong correlation was found between the device dimensions and the temperature limit of the conductance oscillation. Conductance oscillation characteristics of multiple-dot SETs were complicated, and were not explained by the classical Coulomb blockade theory. Based on a simplified theoretical analysis using computer simulation, it was shown that quantized energy due to electron confinement and dot-coupling can dominate the charging effect in the fabricated SETs.