Junction-Less Monolayer MoS2 FETs

This paper introduces monolayer molybdenum disulfide (MoS2) based junction-less (JL) field-effect transistor (FET) and evaluates its performance at the smallest foreseeable (5.9 nm) transistor channel length as per the International Technology Roadmap for Semiconductors (ITRS), by employing rigorous quantum transport simulations. By comparing with MoS2 based conventional FETs, it is found that the JL structure naturally lends MoS2 FETs with superior device electrostatics, and higher ON-current for both high-performance and low-standby-power applications, especially at high impurity doping densities. Along with the advantages of the MoS2 JL-FETs, the effects of impurity scattering induced carrier mobility degradation of JL-FETs is also highlighted as a key technological issue to be addressed for exploiting their unique features

Irradiation of Nanostrained Monolayer WSe2_2 for Site-Controlled Single-Photon Emission up to 150 K

Quantum-dot-like WSe$_2$ single-photon emitters have become a promising platform for future on-chip scalable quantum light sources with unique advantages over existing technologies, notably the potential for site-specific engineering. However, the required cryogenic temperatures for the functionality of these sources have been an inhibitor of their full potential. Existing strain engineering methods face fundamental challenges in extending the working temperature while maintaining the emitter's fabrication yield and purity. In this work, we demonstrate a novel method of designing site-specific single-photon emitters in atomically thin WSe$_2$ with near-unity yield utilizing independent and simultaneous strain engineering via nanoscale stressors and defect engineering via electron-beam irradiation. Many of these emitters exhibit exciton-biexciton cascaded emission, purities above 95%, and working temperatures extending up to 150 K, which is the highest observed in van der Waals semiconductor single-photon emitters without Purcell enhancement. This methodology, coupled with possible plasmonic or optical micro-cavity integration, potentially furthers the realization of future scalable, room-temperature, and high-quality van der Waals quantum light sources

When the Lewisian Dream Sours: Industrial Aspirations and Reverse Labour Migration

The COVID-19 pandemic has escalated processes of labour transition from industrial work to the informal economy, which have always characterized the life of the working poor. This paper explores this kind of reverse transition, that is, when the Lewisian dream of having an industrial job comes to an end, and workers are forced into a reverse migration. Specifically, the paper focuses on the post-industrial experiences of former Indian garment workers leaving the National Capital Region and moving back to Bihar. Emphasis is placed on workers’ reasons for leaving the industry and their current employment and reproductive strategies. Findings are based on a sample of 50 former workers, identified in urban industrial hamlets and traced back to their place of origin. Respondents’ experiences are analysed based on semi-quantitative questionnaires and life histories. Findings reveal that upon leaving the factory, workers find alternative informal employment through caste or social networks whilst using land as safety net. They suggest that farming and informal work are not alternative but rather complementary income and work strategies. By adopting a life-cycle approach to studying labour transitions across formal and informal employment domains, this analysis contributes to policy debates on decent work

The afterlife of industrial work: Urban-to-rural labour transitions from the factory to the informal economy

The COVID-19 pandemic has escalated processes of labour transition from industrial work to the informal economy, which have always characterized the life of the working poor. Exploring urban-to-rural labour transitions through a feminist political economy lens and adopting a life-cycle approach to labour and social reproduction, this paper analyses the post-industrial livelihoods and experiences of former Indian garment workers leaving the National Capital Region and moving back to Bihar. Emphasis is placed on workers’ reasons for leaving the industry and their current employment and reproductive strategies. Findings are based on a sample of 50 former workers, identified in urban industrial hamlets and traced back to their place of origin. Respondents’ experiences are analysed based on semi-quantitative questionnaires and life histories. Findings reveal that upon leaving the factory, workers find alternative informal employment through caste or social networks while using land as safety net. Farming and informal work are not alternative but rather complementary income and work strategies. By adopting a life-cycle approach to studying labour transitions across formal and informal employment domains, this analysis contributes to policy debates on decent work

Modeling techniques and verification methodologies for substrate coupling effects in mixed-signal system-on-chip designs

The substrate noise coupling problems in today's complex mixed-signal system-on-chip (MS-SOC) brings a new set of challenges for designers. In this paper, we propose a global methodology that includes an early verification in the design flow as well as a postlayout iterative optimization to deal with substrate noise, and helps designers to achieve a first silicon-success of their chips. An improved semi-analytical modeling technique exploiting the basic behaviors of this noise is developed. This method significantly accelerates the substrate modeling, avoids the dense matrix storage, and, hence, enables the implementation of an iterative noise-immunity optimization loop working at full-chip level. The integration of the methodology in a typical mixed-signal design flow is illustrated and its successful application to achieve a single-chip integration of a transceiver is demonstrated

Electrical contacts to two-dimensional semiconductors

The performance of electronic and optoelectronic devices based on two-dimensional layered crystals, including graphene, semiconductors of the transition metal dichalcogenide family such as molybdenum disulphide (MoS2) and tungsten diselenide (WSe2), as well as other emerging two-dimensional semiconductors such as atomically thin black phosphorus, is significantly affected by the electrical contacts that connect these materials with external circuitry. Here, we present a comprehensive treatment of the physics of such interfaces at the contact region and discuss recent progress towards realizing optimal contacts for two-dimensional materials. We also discuss the requirements that must be fulfilled to realize efficient spin injection in transition metal dichalcogenides. © 2015 Macmillan Publishers Limited. All rights reserved

An Ultra Energy-Efficient Hardware Platform for Neuromorphic Computing Enabled by 2D-TMD Tunnel-FETs

Brain-like energy-efficient computing has remained elusive for neuromorphic (NM) circuits and hardware platform implementations despite decades of research. In this work we reveal the opportunity to significantly improve the energy efficiency of digital neuromorphic hardware by introducing NM circuits employing two-dimensional (2D) transition metal dichalcogenide (TMD) layered channel material-based tunnel-field-effect transistors (TFETs). Our novel leaky-integrate-fire (LIF) based digital NM circuit along with its Hebbian learning circuitry operates at a wide range of supply voltages, frequencies, and activity factors, enabling two orders of magnitude higher energy-efficient computing that is difficult to achieve with conventional material and/or device platforms, specifically the silicon-based 7 nm low-standby-power FinFET technology. Our innovative 2D-TFET based NM circuit paves the way toward brain-like energy-efficient computing that can unleash major transformations in future AI and data analytics platforms