Moore's Law revisited through Intel chip density.

Gordon Moore famously observed that the number of transistors in state-of-the-art integrated circuits (units per chip) increases exponentially, doubling every 12-24 months. Analysts have debated whether simple exponential growth describes the dynamics of computer processor evolution. We note that the increase encompasses two related phenomena, integration of larger numbers of transistors and transistor miniaturization. Growth in the number of transistors per unit area, or chip density, allows examination of the evolution with a single measure. Density of Intel processors between 1959 and 2013 are consistent with a biphasic sigmoidal curve with characteristic times of 9.5 years. During each stage, transistor density increased at least tenfold within approximately six years, followed by at least three years with negligible growth rates. The six waves of transistor density increase account for and give insight into the underlying processes driving advances in processor manufacturing and point to future limits that might be overcome.

Current trends in nanomaterial embedded field effect transistor-based biosensor.

Recently, as metal-, polymer-, and carbon-based biocompatible nanomaterials have been increasingly incorporated into biosensing applications, with various nanostructures having been used to increase the efficacy and sensitivity of most of the detecting devices, including field effect transistor (FET)-based devices. These nanomaterial-based methods also became the ideal for the amalgamation of biomolecules, especially for the fabrication of ultrasensitive, low-cost, and robust FET-based biosensors; these are categorically very successful at binding the target specified entities in the confined gated micro-region for high functionality. Furthermore, the contemplation of nanomaterial-based FET biosensors to various applications encompasses the desire for detection of many targets with high selectivity, and specificity. We assess how such devices have empowered the achievement of elevated biosensor performance in terms of high sensitivity, selectivity and low detection limits. We review the recent literature here to illustrate the diversity of FET-based biosensors, based on various kinds of nanomaterials in different applications and sum up that graphene or its assisted composite based FET devices are comparatively more efficient and sensitive with highest signal to noise ratio. Lastly, the future prospects and limitations of the field are also discussed.

100 nm AlSb/InAs HEMT for ultra-low-power consumption, low-noise applications.

We report on high frequency (HF) and noise performances of AlSb/InAs high electron mobility transistor (HEMT) with 100 nm gate length at room temperature in low-power regime. Extrinsic cut-off frequencies fT/f max of 100/125 GHz together with minimum noise figure NF(min) = 0.5 dB and associated gain G(ass) = 12 dB at 12 GHz have been obtained at drain bias of only 80 mV, corresponding to 4 mW/mm DC power dissipation. This demonstrates the great ability of AlSb/InAs HEMT for high-frequency operation combined with low-noise performances in ultra-low-power regime.

Functional organic field-effect transistors.

Functional organic field-effect transistors (OFETs) have attracted increasing attention in the past few years due to their wide variety of potential applications. Research on functional OFETs underpins future advances in organic electronics. In this review, different types of functional OFETs including organic phototransistors, organic memory FETs, organic light emitting FETs, sensors based on OFETs and other functional OFETs are introduced. In order to provide a comprehensive overview of this field, the history, current status of research, main challenges and prospects for functional OFETs are all discussed.

Recent progress in n-channel organic thin-film transistors.

Particular attention has been focused on n-channel organic thin-film transistors (OTFTs) during the last few years, and the potentially cost-effective circuitry-based applications in flexible electronics, such as flexible radiofrequency identity tags, smart labels, and simple displays, will benefit from this fast development. This article reviews recent progress in performance and molecular design of n-channel semiconductors in the past five years, and limitations and practicable solutions for n-channel OTFTs are dealt with from the viewpoint of OTFT constitution and geometry, molecular design, and thin-film growth conditions. Strategy methodology is especially highlighted with an aim to investigate basic issues in this field.

Current trends in shrinking the channel length of organic transistors down to the nanoscale.

In this Review article, we highlighted current trends in shrinking the channel length of organic field effect transistors (OFETs) down to the nanoscale in three systems where sophisticated device fabrication has been integrated into the development of different electrodes with nanoscale gaps. The design principle is the combination of molecular design freedom and flexible molecular self-assembly with state-of-the-art device fabrication to realize organic field effect nano-transistors where molecular materials themselves behave as pivotal elements. Three different types of nanoscale electrodes are used for OFETs: metals, single-walled carbon nanotubes (SWCNTs), and graphenes. These electrodes are made by e-beam lithography as well as other complementary methods (shadow deposition, underetching, nanoimprinting, rubber stamping, and microcontact printing).

A hybrid nanomemristor/transistor logic circuit capable of self-programming.

Memristor crossbars were fabricated at 40 nm half-pitch, using nanoimprint lithography on the same substrate with Si metal-oxide-semiconductor field effect transistor (MOS FET) arrays to form fully integrated hybrid memory resistor (memristor)/transistor circuits. The digitally configured memristor crossbars were used to perform logic functions, to serve as a routing fabric for interconnecting the FETs and as the target for storing information. As an illustrative demonstration, the compound Boolean logic operation (A AND B) OR (C AND D) was performed with kilohertz frequency inputs, using resistor-based logic in a memristor crossbar with FET inverter/amplifier outputs. By routing the output signal of a logic operation back onto a target memristor inside the array, the crossbar was conditionally configured by setting the state of a nonvolatile switch. Such conditional programming illuminates the way for a variety of self-programmed logic arrays, and for electronic synaptic computing.

Electronically monitoring biological interactions with carbon nanotube field-effect transistors.

The year 2008 marks the 10th anniversary of the carbon nanotube field-effect transistor (NTFET). In the past decade a vast amount of effort has been placed on the development of NTFET based sensors for the detection of both chemical and biological species. Towards this end, NTFETs show great promise because of their extreme environmental sensitivity, small size, and ultra-low power requirements. Despite the great progress NTFETs have shown in the field of biological sensing, debate still exists over the mechanistic origins underlying the electronic response of NTFET devices, specifically whether analyte species interact with the carbon nanotube conduction channel or if interaction with the NTFET electrodes actually triggers device response. In this tutorial review, we describe the fabrication of NTFET devices, and detail several reports that illustrate recent advances in biological detection using NTFET devices, while highlighting the suggested mechanisms explaining the device response to analyte species. In doing this we hope to show that NTFET technology has the potential for low-cost and portable bioanalytical platforms.

Pushing around electrons: towards 2-D and 3-D molecular switches.

In the new age of molecular electronics there has been a great deal of speculation about ways to control the passage of electrons through organic-based wires using electro- or photo-active switches. However, the next stage development is envisaged as the added sophistication of directionality so that electron migration can be switched into 2 and 3 dimensions. This short tutorial review will set out how this realisation may be achieved and highlight examples where the idea of directionality in electron transfer has been put into practice.