Device Architecture Research Articles

Numerical modelling of lead-free perovskite photodetector with GO as ETM and Cz-N as HTM

Photodetectors (PD) are optoelectronic devices that can convert optical signal into electrical signals via the photoelectric effect. A model of CsSn0.5Ge0.5I3 based nip perovskite photodetector (PePd) with graphene oxide (GO) as electron transport material (ETM) and carbazole unit with naphthalene (Cz-N) is used as hole transport material (HTM) are established. The device configuration was analysed using solar cell capacitance simulator-1 dimensional (SCAPS-1D). The effects of absorber thickness, defect density of CsSn0.5Ge0.5I3, metal work function and operating temperature on device architecture have been investigated. For the incident light between 800-820 nm, a maximum responsivity and detectivity 0.65 A/W and 3.6×1013 Jones are obtained respectively. This simulation results will assist in the future research on high-performance lead-free perovskite photodetectors.

Rational design of hedgehog-like NiMn2S4 architectures for energy storage devices

Rational design of hedgehog-like NiMn2S4 architectures for energy storage devices

A Survey Paper on Plastic Solar Cell Technology

The demand of energy is increasing day by day so non-conventional source of energy has to be used. Sun is the nonconventional source of energy. Conventional solar panels convert solar energy into electrical energy. A plastic solar cell is the type of photovoltaic that makes use of organic electronics dealing with conductive organic polymers or small molecules for light absorption and charge transport to produce electricity from sunlight by the photovoltaic effect. Polymers Provide the Advantage of Solution Processing at Room Temperature, which is Less Expensive and Enables One to Use Plastics. Therefore, If Silicon Is Replaced with Polymer Nanowires, The Solar Cell Would Be Much Lighter and Ultimately Less Costly. These Solar Cells are Thin, Several Microns in Diameter, and Scavenge All the Rays from the Sun's Radiation. Plastic Solar Cell Technology is Based on Conjugated Polymers and Molecules. Polymer Solar Cells have Generated Considerable Interest Since it Provides Environmentally Friendly, Flexible, Lightweight, Low Cost, Possibility of High-Efficiency Solar Cells in the Last Couple of Decades. Plastic Solar Cells are More Efficient and Viable in Usage. This dissertation focuses on the development and optimization of plastic solar cell technology, in particular this potential towards flexible, lightweight, and cost-effective alternative sources to traditional silicon-based solar cells. The focus of the present research work is to find optimum organic materials for higher efficiency and stability in plastic solar cells, varying from conjugated polymers to small organic molecules. Some of the main goals are improving the charge transport mechanisms and optimizing the architecture of devices through state-of-the-art techniques of fabrication, like roll-to-roll printing and layer-by-layer deposition. The other key aspect is that the project assesses the environmental aspects and lifecycle of plastic solar cells to ensure an environmentally friendly production process. Huge preliminary results were achieved at high power conversion efficiencies and durability has been greatly improved, targeting very wide spread application from portable electronics up to building-integrated photovoltaics. Therefore, the discovery of plastic solar cells might be a major step for applicable solutions in renewable energy and towards overcoming the world's increasing energy challenges.

Interfacial Assembly of Peptide Carbon Dot Hybrids Enables Photoinduced Electron Transfer with Improved Photoresponse.

Assemblies at the interface represent a powerful tool for integrating organic and inorganic components into hybrid nanostructures. Carbon dots are both excellent electron donors and acceptors, offering opportunities for their potential uses in light-harvesting applications. To further improve their functions, integration of acceptor carbon dots into donor organic nanostructures is of great interest for improving photophysical properties useful for photoinduced electron transfer. Here, a one-step protocol for the interfacial assembly of a two-component hybrid consisting of carbon dots and perylene containing an l-phenylalanine-based dipeptide through noncovalent bonding is developed. The perylene-containing dipeptide derivative formed micrometer-long nanofibers on the water surface through J-aggregate formation. Spectroscopic studies reveal photoluminescence quenching of the donor dipeptide upon increasing the concentration of acceptor carbon dots in the hybrid, suggesting photoinduced electron transfer from the donor peptides to acceptor carbon dots. The hybrids integrated in a planar device architecture show a significantly improved photoresponse because of the favorable interactions between the donor-acceptor components. The one-step integration of donor-acceptor hybrids on the water surface offers opportunities for light harvesting and related applications.

Microstructural Underpinnings of Giant Intrinsic Exchange Bias in Epitaxial NiCo2O4 Thin Films

AbstractUnderstanding intrinsic exchange bias in nominally single‐component ferromagnetic or ferrimagnetic materials is crucial for simplifying related device architectures. However, the mechanisms behind this phenomenon and its tunability remain elusive, which hinders the efforts to achieve unidirectional magnetization for widespread applications. Inspired by the high tunability of ferrimagnetic inverse spinel NiCo2O4, the origin of intrinsic exchange bias in NiCo2O4 (111) films deposited on Al2O3 (0001) substrates are investigated. The comprehensive characterizations, including electron diffraction, X‐ray reflectometry and spectroscopy, and polarized neutron reflectometry, reveal that intrinsic exchange bias in NiCo2O4 (111)/Al2O3 (0001) arises from a reconstructed antiferromagnetic rock‐salt NixCo1‐xO layer at the interface between the film and the substrate due to a significant structural mismatch. Remarkably, by engineering the interfacial structure under optimal growth conditions, it can achieve exchange bias larger than coercivity, leading to unidirectional magnetization. Such giant intrinsic exchange bias can be utilized for realistic device applications. This work establishes a new material platform based on NiCo2O4, an emergent spintronics material, to study tunable interfacial magnetic and spintronic properties.

Nanohoops Favour Light‐Induced Energy Transfer over Charge Separation in Porphyrin/[10]CPP/Fullerene Rotaxanes

Abstract[2]Rotaxanes offer unique opportunities for studying and modulating charge separation and energy transfer, because the mechanical bond allows the robust, yet spatially dynamic tethering of photoactive groups. In this work, we synthesized [2]rotaxane triads comprising a central (aza)[10]CPP⊃C60 bis‐adduct complex and two zinc porphyrin stoppers to address how the movable nanohoop affects light‐induced charge separation and energy transfer between the rotaxane subcomponents. We found that neither the parent nanohoop [10]CPP nor its electron‐deficient analogue aza[10]CPP actively participate in charge separation. In contrast, the nanohoops completely prevented through‐space charge separation. This result is likely due to supramolecular “shielding”, because charge separation was observed in the thread that acted as reference dyad. On the other hand, the suppression of electron transfer allowed the observation of energy transfer from the porphyrin triplet to the fullerene triplet state with a lifetime of ca. 25 μs. The presence of the interlocked nanohoops therefore leads to a dramatic switch between charge separation and energy transfer. We suggest that our results explain observations made by others in photovoltaic devices comprising nanohoops and may pave the way toward strategic uses of mechanically interlocked architectures in devices that feature (triplet) energy transfer.

Light‐Emitting Perovskite Solar Cells: Genesis to Recent Drifts

Perovskite, a star material with extraordinary opto‐electronic properties has shown promising results in both perovskite solar cells (PSCs) and perovskite light‐emitting diodes (PeLEDs). Taking advantage of the similar configuration of PSCs and PeLEDs, next generation devices with dual functionality of light‐harvesting and light‐emission can be realized. Such devices hold enormous application prospects. However, the necessary tradeoff resulted from the opposite working principles required for each mode of operation and challenges such as non‐radiative recombination loss resulted from bulk and surface defects in perovskite films and mismatched energy levels have hindered mass production. To provide a roadmap for rationally designing efficient light emitting perovskite solar cells (LEPSCs), a comprehensive review focusing on operating principle, device architecture, recent developments and limitations is required. We begin with a brief overview of the basic principles underlying the working mechanism of LEPSCs such as photon to electricity conversion and viceversa. The focus of this review then shift towards deligently combining and overviewing the important breakthroughs reported in this newly developed field such as morphology optimization, defect passivation, interface engineering, energy level alignment and dimensional control. Finally, this work concludes with discussing future challenges and providing a roadmap for rational design of efficient and stable LEPSCs.

Preparation and properties of Cu2MgSnS4 thin films and fabrication of heterojunction devices

Abstract Copper based chalcogenides have garnered growing importance in the area of thin film photovoltaics. Cu2MgSnS4 (CMTS) is one of the newest materials in this family of materials. It is a p-type material which find multiple applications in the field of photovoltaics. Cu2MgSnS4 thin films were deposited onto soda lime glass substrates using automated vacuum spray pyrolysis technique at a substrate temperature of 300 °C and annealed at different temperatures from 300 °C to 375 °C in steps of 25°C. The structural, elemental, morphological, optical, and electrical properties of the material were studied. X-Ray Diffraction studies showed that annealing eliminates impurity phases and improves crystallinity. Field Emission Scanning Electron Microscopy studies showed improved grain size and uniform deposition of the films. The energy bandgap of the as-prepared film is 2.02 eV and that of annealed films are around 2.5 eV. Hall measurements show that the material exhibit p-type conductivity with high value of conductivity, mobility and bulk concentration. Heterojunction devices were fabricated with chemical bath deposited CdS as a buffer layer and spray deposited Aluminium doped Zinc Oxide (Al:ZnO) as n-layer. Silver contacts were placed as electrodes over the top layer. The fabricated device architecture is <FTO/AZO/CdS/CMTS/Ag>. The junction parameters including rectification ratio, knee voltage, series resistance and Ideality factor of all the devices are calculated. The device annealed at 375 °C showed an ideality factor of 2.23, which is the best among all the fabricated devices.

Nanohoops Favour Light-Induced Energy Transfer over Charge Separation in Porphyrin/[10]CPP/Fullerene Rotaxanes.

[2]Rotaxanes offer unique opportunities for studying and modulating charge separation and energy transfer, because the mechanical bond allows the robust, yet spatially dynamic tethering of photoactive groups. In this work, we synthesized [2]rotaxane triads comprising a central (aza)[10]CPP⊃C60 bis-adduct complex and two zinc porphyrin stoppers to address how the movable nanohoop affects light-induced charge separation and energy transfer between the rotaxane subcomponents. We found that neither the parent nanohoop [10]CPP nor its electron-deficient analogue aza[10]CPP actively participate in charge separation. In contrast, the nanohoops completely prevented through-space charge separation. This result is likely due to supramolecular "shielding", because charge separation was observed in the thread that acted as reference dyad. On the other hand, the suppression of electron transfer allowed the observation of energy transfer from the porphyrin triplet to the fullerene triplet state with a lifetime of ca. 25 μs. The presence of the interlocked nanohoops therefore leads to a dramatic switch between charge separation and energy transfer. We suggest that our results explain observations made by others in photovoltaic devices comprising nanohoops and may pave the way toward strategic uses of mechanically interlocked architectures in devices that feature (triplet) energy transfer.

Stretchable and High-Performance Fibrous Sensors Based on Ionic Capacitive Sensing for Wearable Healthcare Monitoring.

Electronic textiles with remarkable breathability, lightweight, and comfort hold great potential in wearable technologies and smart human-machine interfaces. Ionic capacitive sensors, leveraging the advantages of the electric double layer, offer higher sensitivity compared to traditional capacitive sensors. Current research on wearable ion-capacitive sensors has focused mainly on two-dimensional (2D) or three-dimensional (3D) device architectures, which show substantial challenges for direct integration with textiles and compromise their wearing experience on conformability and permeability. One-dimensional (1D) stretchable fiber materials serve as vital components in constructing electronic textiles, allowing for rich structural design, patterning, and device integration through mature textile techniques. Here, a stretchable functional fiber with robust mechanical and electrical performances is fabricated based on semi-solid metal and ionic polymer, which provided a high stretchability and good electrical conductivity, enabling seamless integration with textiles. Consequently, high-performance stretchable fiber sensors are developed through different device architecture designs, including pressure sensors with high sensitivity (7.21kPa-1), fast response (60ms/30ms), and excellent stability, as well as strain sensors with high sensitivity (GF = 1.05), wide detection range (0-300% strain), and excellent sensing stability under dynamic deformations.

Unveiling the potential of direct synthesized PbS CQD ink based solar cells through numerical simulation

Studies on lead sulfide-PbS quantum dot-QD based solar cells have gained considerable attention in recent years. A direct synthesis-DS method has emerged that makes it possible to obtain PbS ink in a single step by eliminating complex synthesis and ligand exchange processes, thus reducing the production cost and time. However, the limited number of studies on cells obtained with this method obscures the high potential of this technique. In this study, various electron-ETL and hole transport layers-HTL were systematically brought together in the SCAPS-1D environment to determine the architecture of the cell with record performance. A photoconversion efficiency-PCE of over 20% was achieved with a cell in which n-type DS PbS inks were combined with TiO2 ETL and MoO3 HTL. Moreover, we found that p-type DS PbS inks have a much higher potential than n-type inks, with a PCE of up to 36%, and most importantly, they are more resistant to increased defect density. We believe that this study, in which the device architecture for DS PbS inks was optimized and structured for the first time and the importance of p-type DS PbS inks was emphasized, will shed light on future studies in the field of solar cell technologies.

Design of superparamagnetic Fe3O4@SiO2@3,4-DABP nanocatalysts, fabrication by co-precipitation and sol-gel methods, characterization of detailed surface texture properties and investigation of solar cell performance

This research focuses on the synthesis, characterization, and evaluation of Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@3,4-DABP magnetic nanocatalysts (MNCs) for their potential use as sensors within the intricate architectures of solar cell devices. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) surface area measurements were carried out to characterize the structural, morphological and magnetic properties of the MNCs. The MNCs exhibit an average particle size of approximately 10 nm. Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2@3,4-DABP MNCs have saturation magnetization values ​​of 61.64 emu/g, 37.31 emu/g, and 20.13 emu/g, respectively. Thermal analysis reveals mass change losses of 6.5%, 12% and 28.1%, respectively, indicating different thermal stability profiles. It confirms that their crystal structure is face-centered cubic spinel, with type IV hysteresis loops and H3 loops indicating a mesoporous structure according to the IUPAC classification. Efficiency tests of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@3,4-DABP MNCs in solar cell devices show efficiencies of 1.49%, 1.77% and 2.15%, respectively. As the hierarchical modification of the MNCs increases, the efficiency of the solar cell devices increases. These results highlight the potential of Fe3O4, Fe3O4@SiO2 and Fe3O4@SiO2@3,4-DABP as promising sensitizers in solar cell technology. Fe3O4@SiO2@3,4-DABP MNCs have high catalytic activity, chemical stability, electronic conductivity and low cost. This study also marks the first demonstration of the effectiveness of environmentally friendly Fe3O4@SiO2@3,4-DABP MNCs in enhancing solar cell performance, prepared via a cost-effective, simple and eco-friendly approach.

Band offset optimization in MAGeI3 based perovskite solar cells

The study focuses on a complete modelling of perovskite solar cell (PSC) employing methyl ammonium germanium iodide (MAGeI3) as light absorbing material via optimizing device’s conduction band offset (CBO) and valence band offset (VBO), which helps in identifying the suitable transport materials that can be employed for extracting the best photovoltaic parameters for solar cell. The device architecture FTO/TiO2/MAGeI3/CuO/Pd has been considered for the study, which after the input parameter optimization provides a power conversion efficiency (PCE) of 12.33 %. An optimization of the CBO of the device configuration results in a PCE of 13.57 %, indicating that the chosen ETL, TiO2 is suitable for the device configuration. An alternate ETL, IGZO with the required electron affinity of 4.18 eV, when tested for the device shows a PCE of 12.39 %. The VBO optimization of the device configuration FTO/TiO2/MAGeI3/CuO/Pd suggests the inclusion of CZTS as the HTL and further input parameter optimization of the device provides PCE of 16.59 %. The VBO optimization of FTO/IGZO/MAGeI3/CuO/Pd suggests for the inclusion of CZTS as the HTL, and provides an excellent PCE of 14.57 %. Hence, the CBO and VBO optimized device configuration, FTO/IGZO/MAGeI3/CZTS/Pd is again optimized by changing the parameters of perovskite and transport layers and a PCE of 20.54 % is achieved. It is further analysed considering diverse back contact metal and optimum PCE of 20.57 % is attained, with Se as the back metal contact. An estimation of the QE of FTO/IGZO/MAGeI3/CZTS/Se configuration indicates efficient charge generation and collection in visible and NIR wavelength regimes.

Device optimization of all-perovskite triple-junction solar cells for realistic irradiation conditions

All-perovskite two-terminal tandem solar cells, comprising two or more junctions, offer high power conversion efficiencies (PCEs) that exceed the limits of single-junction photovoltaics. Realizing high-efficiency SCs requires carefully optimizing the photoactive layer, front electrodes, and functional layers. Here, we first aim to determine the optimal device architecture, i.e., the perovskites bandgaps and optimum layer thicknesses, for standard test conditions (STCs). We then optimize the energy yield (EY) under realistic outdoor conditions (ROCs), i.e., the overall electrical energy to be expected in one year at a specific location. In the first step, we reference our simulation with two terminal all-perovskite triple-junction SCs (2T3J-PSCs) to previously experimentally realized PSC with a PCE of 20.1% as a benchmark to derive the underlying diode parameters and use our in-house energy yield code combined with a hybrid particle swarm optimization and gravitational search algorithm (PSOGSA) to find the optimal bandgap combination and perovskite layer thicknesses. The optimized SCs with the optimal bandgap combination offer a PCE of 25.1% with a current density of 10.1 mA/cm2. Furthermore, the effect of the other functional layers, such as transparent conductive oxide (TCO), hole transport layer (HTL), and recombination junctions (RJs), is also investigated to enhance the cell performance further. The SCs with optimized layers exhibit improved parameters: PCE of 27.1%, with a relative improvement of 34.8% in the PCE compared with the fabricated cell, and a high current matching a of 10.8 mA/cm2. The numerical results showed that the reported cell can potentially achieve a PCE of 36% at an eVoc/EG ratio of 0.72. However, the optimal parameters may vary in real-world operating conditions due to variations in temperature, humidity, and light exposure. As a result, the optimal energy yield (EY) parameters may differ. Therefore, the energy yield optimizing process is also carried out by considering ROCs in Phoenix, AZ, USA, to find the best parameters under these conditions. We found that the optimum top layer bandgap under ROCs is lower than under STCs due to a bluer, more shifted spectrum in ROCs. After that, the optimized cell under ROCs is tested in several locations exhibiting different climatic conditions (Seattle, Honolulu, Los Angeles, Miami, and Milwaukee). The numerical results show that the optimized cell under ROCs offers an increase in energy yield in several locations compared to conventional single-junction crystalline Si-SCs (PCE = 23.6%) with a high energy yield of 648.2 kWh/m2 in Phoenix, with an improvement of 39.9% in the EY compared to the Si-SC counterpart. Our results provide design guidelines for fabricating a highly efficient triple-junction perovskite SC in the lab and outdoor applications and improve the efficiency of 2T3J-PSCs beyond the 30% limit.

Machine Learning Approaches in Advancing Perovskite Solar Cells Research

AbstractThe integration of machine learning (ML) with perovskite solar cells (PSCs) signifies a groundbreaking era in photovoltaic (PV) technology. The traditional iterative approaches in PSC research are often time‐consuming and resource‐intensive. In contrast, ML leverages available data and sophisticated algorithms to quickly identify properties and optimize parameters for novel materials and devices. This review explores how ML‐driven approaches are improving various facets of PSCs research, including the rapid screening of novel compositions, enhancing stability, refining device architectures, and deepening the understanding of underlying physics. The paper is structured to gradually familiarize readers with essential terminologies and concepts, ensuring a solid foundation before delving into more intricate topics. A concise workflow and various introductory toolkits for ML are also briefly discussed. Through a detailed analysis of compelling case studies, a basic research framework within ML‐PSC‐integrated research is provided. This comprehensive review can serve as a valuable reference for researchers aiming to understand and leverage ML‐driven approaches in PSCs research, advancing the path for more efficient and sustainable PV technologies.

Scalable Multispecies Ion Transport in a Grid-Based Surface-Electrode Trap

Quantum processors based on linear arrays of trapped ions have achieved exceptional performance, but scaling to large qubit numbers requires realizing two-dimensional ion arrays as envisioned in the quantum charge-coupled device (QCCD) architecture. Here, we present a scalable method for the control of ion crystals in a grid-based surface-electrode Paul trap and characterize it in the context of transport operations that sort and reorder multispecies crystals. By combining cowiring of control electrodes at translationally symmetric locations in each grid site with the sitewise ability to exchange the voltages applied to two special electrodes gated by a binary input, site-dependent operations can be achieved using only a fixed number of analog voltage signals and a single digital input per site. In two separate experimental systems containing nominally identical grid traps, one using Yb+171−Ba+138 crystals and the other Ba+137−Sr+88, we demonstrate this method by characterizing the conditional intrasite crystal reorder and the conditional exchange of ions between adjacent sites on the grid. Averaged across a multisite region of interest, we measure subquanta motional excitation in the axial in-phase and out-of-phase modes of the crystals following these operations at exchange rates of 2.5 kHz. In this initial demonstration, the logic controlling the voltage exchange occurs in software, but the applied signals mimic a proposed hardware implementation using crossover switches. These techniques can be further extended to implement other conditional operations in the QCCD architecture such as gates, initialization, and measurement. Published by the American Physical Society 2024

Cracking the Core: Hardware Vulnerabilities in Android Devices Unveiled

As Android devices become more prevalent, their security risks extend beyond software vulnerabilities to include critical hardware weaknesses. This paper provides a comprehensive and systematic review of hardware-related vulnerabilities in Android systems, which can bypass even the most sophisticated software defenses. We compile and analyze an extensive range of reported vulnerabilities, introducing a novel categorization framework to facilitate a deeper understanding of these risks, classified by affected hardware components, vulnerability type, and the potential impact on system security. The paper addresses key areas such as memory management flaws, side-channel attacks, insecure system-on-chip (SoC) resource allocation, and cryptographic vulnerabilities. In addition, it examines feasible countermeasures, including hardware-backed encryption, secure boot mechanisms, and trusted execution environments (TEEs), to mitigate the risks posed by these hardware threats. By contextualizing hardware vulnerabilities within the broader security architecture of Android devices, this review emphasizes the importance of hardware security in ensuring system integrity and resilience. The findings serve as a valuable resource for both researchers and security professionals, offering insights into the development of more robust defenses against the emerging hardware-based threats faced by Android devices.

Enhancing Stability in All-Vacuum-Evaporated Hybrid Perovskite Solar Cells via a Bipolar Host as a Hole-Transporting Layer.

Growing an ultrathin hybrid organic-inorganic perovskite film while maintaining high efficiency and addressing photostability challenges for commercial devices remains a significant hurdle. In this study, we explore the incorporation of organometallic copper phthalocyanine (CuPc) and MS-OC (a previously published spiro-based interfacial material for perovskite solar cells (PSCs), featuring an ortho-oriented carbazole donor) as an addition to the hole-transporting layer (HTL) in all-vacuum-deposited Cs0.06FA0.94Pb(I0.68Br0.32)3 PSCs. By innovatively introducing a 3 nm-thin MS-OC layer at the CuPc-perovskite interface, we achieve a deeper understanding of the crystallographic dynamics of perovskites, resulting in a uniform and pinhole-free film. We demonstrate that PSCs utilizing the CuPc HTL with an MS-OC interfacial layer in a p-i-n architecture achieve a power conversion efficiency (PCE) of up to 14.42%. Remarkably, the CuPc/MS-OC-based device exhibits outstanding long-term photostability, maintaining its initial PCE over 400 h (T100 = 400 h) under continuous sunlight illumination. By configuring the device architecture as ITO/MoO3/CuPc/MS-OC/perovskite/C60/BCP/Ag, we find that the evaporated MS-OC thin films effectively reduce nonradiative losses, passivate the perovskite, and enhance device performance. Our findings indicate that the polarity of the underlying surface significantly influences perovskite nucleation, underscoring the potential to improve photostability by controlling interfacial imperfections.

Optical control of multiple resistance levels in graphene for memristic applications

Neuromorphic computing has emphasized the need for memristors with non-volatile, multiple conductance levels. This paper demonstrates the potential of hexagonal boron nitride (hBN)/graphene heterostructures to act as memristors with multiple resistance states that can be optically tuned using visible light. The number of resistance levels in graphene can be controlled by modulating doping levels, achieved by varying the electric field strength or adjusting the duration of optical illumination. Our measurements show that this photodoping of graphene results from the optical excitation of charge carriers from the nitrogen-vacancy levels of hBN to its conduction band, with these carriers then being transferred to graphene by the gate-induced electric field. We develop a qualitative model to describe our observations. Additionally, utilizing our device architecture, we propose a memristive crossbar array for vector-matrix multiplications.

In-Silico Design and Optimization of p-BaSi₂/n-Bi₂S₃ Heterojunction for Enhanced Photovoltaic Performance

This study aims to explore the integration of Bi2S3 as an electron transport layer (ETL) in BaSi2-based thin-film solar cells for the enhanced performance. Using the globally accepted SCAPS-1D simulation tool, a novel device architecture consisting of Al/SnO2:F/Bi2S3/BaSi2/Ni was systematically designed and optimized. Key optimization parameters include the thicknesses, carrier concentrations, bulk defect densities of each layer, interface defects, operating temperature, and the influence of series and shunt resistance on overall efficiency. The simulation results reveal that a BaSi2 layer with an optimized thickness of 1 µm and a doping concentration of 5 x 1019 cm-3, yields noteworthy outcomes. Specifically, champion efficiency (