Mixed-Mode Optical/Electric Simulation of Silicon Lateral PIN Photodiode Using FDTD Method

Silicon - Within this paper, a total optoelectronic simulation of a PIN photodiode structure was presented. The microlens structure has been introduced on the top of the PIN photodiode to...     

Layered Titanium Carbide-Mediated Fast Shape Switching and Excellent Thermal and Electrical Transport in Shape-Memory-Polymer Composites for Smart Technologies: MAX Versus MXene

Stimuli-responsive materials can frequently tune between their temporary and original shapes, and have the potential for artificial intelligence-based technologies in robotics, aerospace, biomedical, engineering, security, etc. Shape memory polymers (SMPs) are promising for these technologies but their inadequate thermal and electrical characteristics causing slow shape recovery limit their practical applications. Herein, for the first time, comprehensively and precisely the shape memory polyurethane (PU), a promising SMP, via a variety of novel layered titanium carbides fillers, namely, Ti₂AlC (MAX₁), Ti₃AlC₂ (MAX₂), and Ti₃C₂ (MXene), is engineered. The resultant PU-composites show 30–50% faster shape recovery in different environments, 20–25% greater extent of shape recovery in the load-constrained environment, 100–125% higher thermal conductivity, and 700–16 000× higher electrical current. Importantly, the reinforcement of even a small amount of MAX and MXene (such as 0.25 wt%) has largely boosted the performance of PU. Considering ease of processability and performance enhancement factors, the MAX-phase fillers may be preferred over MXene-phase fillers for next-generation composites development. Employing PU composite component as both heat-sensor and actuator, a unique heat detector/fire alarm device that works successfully in simulated heat and fire environments is demonstrated. This work is crucial for enabling futuristic technologies.     

Characterization and analysis of low-noise GaN-HEMT based inverter circuits

Microsystem Technologies - In this work, the authors have propounded a novel Gallium Nitride High Electron Mobility Transistor (GaN-HEMT) structure and have analyzed its DC, RF and noise...     

Temperature‐dependent modeling and performance analysis of coupled MLGNR interconnects

The temperature‐dependent circuit modeling and performance in terms of propagation delay, power dissipation, and crosstalk‐induced voltage waveform at the far end of victim line of multilayer graphene nanoribbon (MLGNR) interconnects have been analyzed at 22 nm technology node. A comparative performance analysis between MLGNR interconnects with resistance estimated using temperature‐dependent model and temperature‐independent model is examined. The results obtained are also compared with capacitively coupled interconnects of copper (Cu). The results show that as the temperature is varied from 300 K to 500 K, MLGNR has lower propagation delay and power dissipation as compared to Cu for 1 mm long interconnects. It is also observed that because of the dominance of both low resistance and ground capacitance compared to Cu, MLGNR has better crosstalk‐induced delay and voltage waveforms with rise in temperature at the far end of aggressor and victim line, respectively. Further, simulated results show an average relative improvement in propagation delay of 37.24% and corresponding improvement in power dissipation of approximately 19.59% by using a temperature‐dependent model in comparison to a temperature‐independent model of MLGNR resistance with interconnect lengths varying from 200 to 1000 μm. The reduction in the time duration of victim output pulse over these interconnect lengths also shows a significant improvement of approximately 35% by using temperature‐dependent model as against temperature‐independent model of MLGNR resistance.     

Advances in DNA Origami–Cell Interfaces

The nascent field of DNA nanotechnology has undergone rapid growth since its inception. By using DNA as a biologically “safe” material, DNA nanotechnology shows great promise in applications such as drug-delivery systems. Further progress, however, relies on understanding the different ways in which DNA nanostructures behave in and interact with cells, tissues and even whole organisms. Moreover, this knowledge must then be harnessed in innovative ways to improve existing DNA nanostructures and design new ones, so that they can perform more diverse functions more effectively. There have been many developments in this regard in the past few years, and herein some of these are highlighted, with respect to both works that improve our understanding of what happens to DNA nanostructures once they are at their target site, and those that utilise clever design to accomplish desired functions.     

Performance and Analysis of Stack Junctionless Tunnel Field Effect Transistor

Silicon - To overcome the fabrication complexity and achieve a better switching ratio is a major grave concern for applications in semiconductor devices. In this regards, a novel stack gate-oxide...     

Excellent boron emitter passivation for high‐efficiency Si wafer solar cells using AlOx/SiNx dielectric stacks deposited in an industrial inline plasma reactor

Excellent passivation of boron emitters is realised using AlO_x/SiN_x dielectric stacks deposited in an industrial inline plasma‐enhanced chemical vapour deposition reactor. Very low emitter saturation current density (J_0e) values of 10 and 45 fA/cm² are obtained for 180 and 30 Ω/sq planar p⁺ emitters, respectively. For textured p⁺ emitters, the J_0e was found to be 1.5–2 times higher compared with planar emitters. The required thermal activation of the AlO_x films is performed in a standard industrial fast‐firing furnace, making the developed passivation stack industrially viable. We also show that an AlO_x thickness of 5 nm in the AlO_x/SiN_x stack is sufficient for obtaining a J_0e of 18 fA/cm² for planar 80 Ω/sq p⁺ emitters, which corresponds to a 1‐sun open‐circuit voltage limit of the solar cell of 736 mV at 25 °C. Copyright © 2012 John Wiley & Sons, Ltd.     

Fabrication,characterization,numerical simulation and compact modeling of P3HT based organic thin film transistors

This paper presents the fabrication,characterization and numerical simulation of poly-3-hexylthiophene (P3HT)-based bottom-gate bottom-contact (BGBC) organic thin film transistors (OTFTs).The simulation is based on a drift diffusion charge transport model and density of defect states (DOS) for the traps in the band gap of the P3HT based channel.It com-bines two mobility models,a hopping mobility model and the Poole-Frenkel mobility model.It also describes the defect dens-ity of states (DOS) for both tail and deep states.The model takes into account all the operating regions of the OTFT and in-cludes sub-threshold and above threshold characteristics of OTFTs.The model has been verified by comparing the numerically simulated results with the experimental results.This model is also used to simulate different structure in four configurations of OTFT e.g.bottom-gate bottom-contact (BGBC),bottom-gate top-contact (BGTC),top-gate bottom-contact (TGBC) and top-gate top-contact (TGTC) configurations of the OTFTs.We also present the compact modeling and model parameter extraction of the P3HT-based OTFTs.The extracted compact model has been further applied in a p-channel OTFT-based inverter and three stage ring oscillator circuit simulation.     

SEAI: Secrecy and Efficiency Aware Inter-gNB Handover Authentication and Key Agreement Protocol in 5G Communication Network

Recently, the Third Generation Partnership Project (3GPP) has initiated the research in the Fifth Generation (5G) network to fulfill the security characteristics of IoT-based services. 3GPP has proposed the 5G handover key structure and framework in a recently published technical report. In this paper, we evaluate the handover authentication mechanisms reported in the literature and identify the security vulnerabilities such as violation of global base-station attack, failure of key forward/backward secrecy, de-synchronization attack, and huge network congestion. Also, these protocols suffer from high bandwidth consumption that doesn’t suitable for energy-efficient mobile devices in the 5G communication network. To overcome these issues, we introduce Secrecy and Efficiency Aware Inter-gNB (SEAI) handover Authentication and Key Agreement (AKA) protocol. The formal security proof of the protocol is carried out by Random Oracle Model (ROM) to achieve the session key secrecy, confidentiality, and integrity. For the protocol correctness and achieve the mutual authentication, simulation is performed using the AVISPA tool. Also, the informal security evaluation represents that the protocol defeats all the possible attacks and achieves the necessary security properties.Moreover, the performance evaluation of the earlier 5G handover schemes and proposed SEAI handover AKA protocol is carried out in terms of communication, transmission, computation overhead, handover delay, and energy consumption. From the evaluations, it is observed that the SEAI handover AKA protocol obtains significant results and strengthens the security of the 5G network during handover scenarios.