Findings and reports in the field of perovskite solar cells (PSCs) have been phenomenal and embrace diverse perspectives such as technical issues, yielding, marketing, and environmental concerns. Bottlenecks in the structure, manufacturing, and operation of PSCs have been frequently addressed; the use of various means including crystallography and kinetics studies, simulation, material, solution, and surface/interface engineering, as well as their outcomes, have yielded certified efficiency of 23.7%. However, the short lifecycle, large waste-to-harvest ratio, functional failure during bending and in the dark mode, environmental and stability issues, and lack of power storage hinder their commercial viability. As a remedy, PSCs can be teamed up with one or multiple mechanical or thermal energy-harvesting or electrochemical power storage devices that can fully or partially overcome these nonidealities. Here, the means of integrating different devices with PSCs to form hybrid packs are discussed. The factors contributing toward the efficiency and mechanical robustness of PSCs and their hybrid devices upon integration are investigated. As an essential bridging component, carbon electrodes are also considered. Furthermore, due to the pressing standards in the energy sector, hybrid devices with nontoxic lead (Pb)-free perovskites should form ideal power packs. Therefore, with reference to their lattice model, optical characteristics, and resulting photovoltaic (PV) performance, they have also been briefly highlighted.

Perovskite solar cell-hybrid devices: thermoelectrically, electrochemically, and piezoelectrically connected power packs

Wide energy gap semiconductors are broadly recognized as promising materials for novel electronic and opto-electronic device applications. As informed device design requires a firm grasp on the material properties of the underlying electronic materials, the electron transport that occurs within the wide energy gap semiconductors has been the focus of considerable study over the years. In an effort to provide some perspective on this rapidly evolving and burgeoning field of research, we review analyzes of the electron transport within some wide energy gap semiconductors of current interest in this paper. In order to narrow the scope of this review, we will primarily focus on the electron transport that occurs within the wurtzite and zinc-blende phases of gallium nitride and indium nitride in this review, these materials being of great current interest to the wide energy gap semiconductor community; indium nitride, while not a wide energy gap semiconductor in of itself, is included as it is often alloyed with other wide energy gap semiconductors, the resultant alloy often being a wide energy gap semiconductor itself. The electron transport that occurs within zinc-blende gallium arsenide will also be considered, albeit primarily for bench-marking purposes. Most of our discussion will focus on results obtained from our ensemble semi-classical three-valley Monte Carlo simulations of the electron transport within these materials, our results conforming with state-of-the-art wide energy gap semiconductor orthodoxy. A brief tutorial on the Monte Carlo electron transport simulation approach, this approach being used to generate the results presented herein, will also be provided. Steady-state and transient electron transport results are presented. The evolution of the field, a survey of the current literature, and some applications for the results presented herein, will also be featured. We conclude our review by presenting some recent developments on the electron transport within these materials. This review is the latest in a series of reviews that have been published on the electron transport processes that occur within the class of wide energy semiconductor materials. The results and references have been updated to include the latest developments in this rapidly evolving field of study.

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Electron transport within the wurtzite and zinc-blende phases of gallium nitride and indium nitride

This paper presents a comprehensive TCAD based assessment to evaluate the intrinsic gain and minimum noise figure metrics of the T – Gate, and the π – Gate AlGaN/AlN/GaN HEMTs along with their recessed architectures. The work presented in this paper, to the best of author’s knowledge, is first in its attempt to systematically bring out both the effect of minimum noise figure metrics and intrinsic gain at the device level for the π – Gate architecture and their recessed counterparts whilst evaluating its stability for high frequency operations. Comparison demonstrates an enhancement in intrinsic gain by 64.5% in case of asymmetric π – Gate and 77% for asymmetric recessed π – Gate in comparison to their T – Gate counterparts. Further, the said architectures possess a wider range of flat gain operation with suppressed values of minimum noise figure metrics. These modifications result in a modest trade off in the minimum noise figures when best case is considered and compared with their T – Gate counterparts. Additionally, it is also demonstrated that such device architectures demonstrate much stable high frequency operation in comparison to their primer. The results so presented establish the superiority of the π – Gate AlGaN/AlN/GaN HEMTs for low noise and high gain applications.

Optimization of π – Gate AlGaN/AlN/GaN HEMTs for Low Noise and High Gain Applications

In this research paper, a simple clock wise and counter clock wise Schmitt trigger employing single four terminal floating nullor (FTFN) with two external resistors is presented. The proposed Schmitt trigger avails CMOS based FTFN and it is extended for the application as a square and triangular wave generator, by adding an external capacitor to it. In addition, the proposed waveform generator provides independent tunability of amplitude of square wave by implementing the passive resistors using MOS transistors which make the circuit to be integrated fully. Finally, the verification of the proposed design is verified using PSPICE to justify the theoretical analysis. Also, post layout simulation and the experimental verification using commercially available current feedback operational amplifier named as ICAD844 based implementation for FTFN are included to confirm the reliability of the circuit.

A novel Schmitt trigger and its application using a single four terminal floating nullor (FTFN)

A novel multiple-output dual-X current conveyor transconductance amplifier with buffer-based square/triangular wave generator is introduced in the paper. The proposed generator provides square wave...

Fully Electronically Tunable and Easily Cascadable Square/Triangular Wave Generator with Duty Cycle Adjustment

This paper presents a self-generating square/triangular wave generator using only the CMOS Operational Transconductance Amplifiers (OTAs) and a grounded capacitor. The output frequency and amplitude of the proposed circuit can be independently and electronically adjusted. The proposed circuit validates its advantage by consuming less amount of power, which is about 71.3 µW. The theoretical aspects are authentically showcased using the PSPICE simulation results. The performance of the proposed circuit is also verified through pre layout and post layout simulation results using the 90 nm GPDK CMOS parameters. A prototype of this circuit has been made using commercially available IC CA3080 for experimental verification. Experimentation also gives the similar output as per the theoretical proposition. The designed circuit is also made applicable to perform pulse width modulation (PWM).

Generation of square and triangular wave with independently controllable frequency and amplitude using OTAs only and its application in PWM

Nanocrack formation due to inverse piezoelectric effect in AlGaN/GaN HEMT

Internet of Things (IoT) applications are connecting several Mobile Stations (MSs) to form the Mobile Communication Network (MCN). MSs are moving through macrocell and picocell recurrently due to t...

CBLM: Cluster-Based Location Management for 5G Small Cell Network Under Stochastic Environment

Analysis of electron transport in AlGaN/GaN superlattice HEMTs for isotopes 14 N and 15 N

Tunneling effect has been studied in double barrier (AlGaN/GaN) heterostructure and tunneling probability has been found out for electrons to tunnel across the barrier. Tunneling probability changes as the temperature changes. Here tunneling probability has been taken at very low temperature (77K). The potential distribution has been shown in the heterostructure. Tunneling current for double barrier nitride (AlGaN/GaN) heterostructure has been traced and revealed figure of merit at 77K equals about 15.

Kaushik Mazumdar

Papers

Generation of square and triangular wave with independently controllable frequency and amplitude using OTAs only and its application in PWM

Nanocrack formation due to inverse piezoelectric effect in AlGaN/GaN HEMT

CBLM: Cluster-Based Location Management for 5G Small Cell Network Under Stochastic Environment

Analysis of electron transport in AlGaN/GaN superlattice HEMTs for isotopes 14 N and 15 N

TUNNELING EFFECT IN DOUBLE BARRIER NITRIDE (AlGaN/GaN) HETEROSTRUCTURES AT VERY LOW TEMPERATURE