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In this article, a field‐plated and recessed gate III‐Nitride Nano‐HEMT developed on β‐Ga2O3 substrate is proposed and investigated for various performance characteristics over different temperatures. The 2DEG (Two Dimensional Electron Gas) dependence on temperature is critical for commercial utilization of GaN‐based HEMTs (high electron mobility transistors). Here, the temperature influence on 2DEG for proposed HEMT over the range of 300–400 K has been investigated. The results demonstrate that the 2DEG density of proposed HEMT reduces as temperature increases. It has been observed that phonon scattering results in a sharp decline in the mobility of 2DEG as temperature increases, which causes the electric field to decrease. It also exhibited that the cut‐off frequency decreased over the temperature changes from 300 to 400 K due to diminution in electron mobility. This research aims to contribute an extensive overview of proposed III‐Nitride Nano‐HEMT designed on a lattice‐matched substrate of β‐Ga2O3 to foster future research on the latest developments in this field. [ABSTRACT FROM AUTHOR]

This paper examines advances in ultra-high concentration photovoltaics (UHCPV), focusing specifically on vertical multijunction (VMJ) solar cells. The use of gallium arsenide (GaAs) in these cells increases their efficiency in a range of applications, including terrestrial and space settings. Several multijunction structures are designed to maximize conversion efficiency, including a vertical tunnel junction, which minimizes resistive losses at high concentration levels compared with standard designs. Therefore, careful optimization of interconnect layers in terms of thickness and doping concentration is needed. Homo-multijunction GaAs solar cells have been simulated and analyzed by using ATLAS Silvaco 5.36 R, a sophisticated technology computer-aided design (TCAD) tool aimed to ensure the reliability of simulation by targeting a high conversion efficiency and a good fill factor for our proposed structure model. Several design parameters, such as the dimensional cell structure, doping density, and sun concentrations, have been analyzed to improve device performance under direct air mass conditions AM1.5D. The optimized conversion efficiency of 30.2% has been achieved with investigated GaAs solar cell configuration at maximum concentration levels. [ABSTRACT FROM AUTHOR]

In this paper, we report DC and RF analysis of a T‐gate AlN/β‐Ga2O3 high electron mobility transistors (HEMTs) by optimizing the gate‐drain distance (LGD) and two T‐gate dimensions given by the—head‐length (LHL) and the foot‐length (LFL). A two‐dimensional (2‐D) physics‐based device simulator attuned with experimental results is used to perform the analysis. The AlN/β‐Ga2O3 HEMT achieves a high two‐dimensional electron gas (2DEG) density of ~3 × 1013 cm−2, which is attributed to large spontaneous as well as piezoelectric polarization components of the 10 nm AlN thick barrier layer. 2DEG density is also numerically validated using widely used polarization model for III nitrides. It is demonstrated that a highly scaled, both lateral and vertical, device with optimized T‐gate dimensions achieves higher blocking voltage (VBR), low on‐resistance (RON), higher cut‐off frequency (fT) and higher maximum oscillation frequency (fMAX), simultaneously. Consequently, AlN/β‐Ga2O3 HEMT achieves a low specific‐on resistance (RON,sp) of 0.1 mΩ cm2 and an off‐state breakdown voltage of 904 V, which corresponds to the record power figure‐of‐merit (PFoM) of ~8172 MW/cm2. Furthermore, fT of 73 GHz and fMAX of 142 GHz are estimated. These results—low power conduction loss along with higher blocking voltage, and superior RF parameters show the potential of the analyzed device T‐gate AlN/β‐Ga2O3 HEMT for high‐power switching and RF applications. [ABSTRACT FROM AUTHOR]

In this research article, a recessed field-plated gate AlGaN/GaN-based nano-high electron mobility transistor (HEMT) grown on a β-Ga2O3 substrate is designed with and without insertion of AlN layer between AlGaN and GaN layers. The impact of intended AlN layer on the proposed HEMT’s carrier transport features, DC, and RF characteristics are discussed in this study. The outcome shows that introducing a thin AlN spacer layer induces the location of two-dimensional electron gas (2DEG) to shift away from AlGaN/GaN interface. Furthermore, the influence of different AlN thicknesses is studied. It has been observed that the 2DEG concentration rises as AlN layer thickness increases. In general, the mobility of 2DEG is reduced in typical HEMTs due to scatterings induced by alloy and interface roughness. The outcomes demonstrated that a 2 nm-thick AlN layer exhibited the least amount of interface scattering, which results into highest charge carrier mobility. The proposed nano-HEMT demonstrated an enhanced transport, DC and RF properties with the utilization of a lower lattice mismatched β-Ga2O3 material as a substrate, and the positioning of an AlN layer of thickness 2 nm between upper Al0.3Ga0.7N barrier and GaN buffer layers. [ABSTRACT FROM AUTHOR]

Lightweight and flexible electronics have recently emerged at the forefront of optoelectronic applications. In this regard, graphene electrodes enable opportunities for new photodiode devices. In this paper, we formulated and tested graphene ink using the standard inkjet printing technique. It was shown that the maximum conductivity of ink was achieved for 14 print passes of the graphene layer. Moreover, we deposited Molybdenum Disulfide (MoS2) ink in the same pattern and used it as an active layer. We put MoS2 ink on an Indium-Tin-Oxide (ITO) glass substrate and then deposited graphene ink as a top electrode to fabricate an ITO/MoS2/graphene device. The fabricated device showed good rectification behavior and high ON/OFF switching behavior with a max photocurrent of 15 µA at +2 V. The technique thus paves the way for low-cost, low-temperature processing of electronics and one-step fabrication. [ABSTRACT FROM AUTHOR]

In this piece of work, a recessed gate field‐plated AlGaN/AlN/GaN HEMT on β‐Ga2O3 substrate is proposed and its performance characteristics are compared with HEMT structure employing a recessed gate (depth of 25, 30 and 35 nm) without field‐plate. The device is simulated to obtain breakdown voltage, microwave frequency characteristics (fT, fmax) and JFOM using Atlas TCAD. The cut‐off frequency and maximum frequency of oscillations are 420 and 720 GHz, respectively, which are excellent than those reported in recent studies. For 20 nm gate length, the suggested HEMT achieves the maximum JFOM of 45.3 THz‐V. These fT, fmax and JFOM demonstrate that the proposed HEMT on β‐Ga2O3 substrate is an excellent candidate for emerging microwave and millimetre wave applications. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of ultrathin Cu (In1−xGax) Se2 solar cell which was calibrated from the fabricated cell using Silvaco-TCAD tools. Carrier transport mechanism and conduction band alignment at the CdS/CIGS interface shows a large influence on PV parameters. The influence of the absorber trap density on the electrical characteristics of the single junction cell was investigated under AM 1.5G one-sun (100 mW/cm2) illumination. Further simulations quantify significant improvements in cell efficiency while using a thin Al2O3 material as a rear passivation layer. In addition, the impact of the backside pitch size, opening width, absorber layer doping, and thickness on cell performance is investigated to enhance the cell efficiency. To evaluate our work, the electrical characteristics of the optimized cell were compared to the fabricated cells. [ABSTRACT FROM AUTHOR]

The FinFET architecture has attracted growing attention over the last two decades since its invention, owing to the good control of the gate electrode over the conductive channel leading to a high immunity from short-channel effects (SCEs). In order to contribute to the advancement of this rapidly expanding technology, a 3D 14-nm SOI n-FinFET is performed and calibrated to the experimental data from IBM by using Silvaco TCAD tools. The calibrated TCAD model is then investigated to analyze the impact of changing the fin width, fin height, gate dielectric material, and gate length on the DC and RF parameters. The achieved results allow gaining a better understanding and a deeper insight into the effects of varying the physical dimensions and materials on the device performance, thereby enabling the fabrication of a device tailored to the given constraints and requirements. After analyzing the optimal values from different changes, a new device configuration is proposed, which shows a good improvement in electrical characteristics. [ABSTRACT FROM AUTHOR]