Enhanced Device Performance Research Articles

First-principles investigations of metal-semiconductor MoSH@MoS2 van der Waals heterostructures.

Two-dimensional (2D) metal-semiconductor heterostructures play a critical role in the development of modern electronics technology, offering a platform for tailored electronic behavior and enhanced device performance. Herein, we construct a novel 2D metal-semiconductor MoSH@MoS2 heterostructure and investigate its structures, electronic properties and contact characteristics using first-principles investigations. We find that the MoSH@MoS2 heterostructure exhibits a p-type Schottky contact, where the specific Schottky barrier height varies depending on the stacking configurations employed. Furthermore, the MoSH@MoS2 heterostructures possess low tunneling probabilities, indicating a relatively low electron transparency across all the patterns of the MoSH@MoS2 heterostructures. Interestingly, by modulating the electric field, it is possible to modify the Schottky barriers and achieve a transformation from a p-type Schottky contact into an n-type Schottky contact. Our findings pave the way for the development of advanced electronics technology based on metal-semiconductor MoSH@MoS2 heterostructures with enhanced tunability and versatility.

Strain Management in Perovskite Solar Cells

Perovskite solar cells (PSCs) currently hold the record for highest power conversion efficiency (PCE) at an impressive 25.7%. However, the state-of-the-art PCEs still fall below theoretical limits, and the long-term stability remains a critical concern for practical implementation of PSCs. Due to the soft ionic nature of metal halide perovskites, the inevitable strain effect on perovskite films has been found to be a key factor in determining both efficiency and stability. In this review, we summarize the recent advancements on the origins of strain, the characterization methodologies, and the impact of strain on perovskite films, as well as various strategies employed to regulate strain and enhance the intrinsic performance of perovskites and solar cells. Our intention is to facilitate scientists with an exhaustive comprehension of the strain effect, and stimulate research endeavors in strain management aimed at enhancing device performance and commercialization.

Regulating charge carrier recombination in Cu2ZnSn(S,Se)4 solar cells via cesium treatment: bulk and interface effects

Cs treatment in a CZTSSe system could enhance device performance by affecting defect characteristics and carrier–transport properties.

Role of a corrugated Dion-Jacobson 2D perovskite as an additive in 3D MAPbBr3 perovskite-based light emitting diodes.

Metal halide perovskites represent an intriguing class of materials, and a very promising approach to tune the properties of optoelectronic devices and improve their performance involves the implementation of architectures based on mixed 3D and 2D perovskites. In this work, we investigated the use of a corrugated 2D Dion-Jacobson perovskite as an additive to a classical 3D MAPbBr3 perovskite for applications in light-emitting diodes. Taking advantage of the properties of this emerging class of materials, we studied the effect of a 2D 2-(dimethylamino)ethylamine (DMEN)-based perovskite on the morphological, photophysical, and optoelectronic properties of 3D perovskite thin films. We used α-DMEN perovskite both in a mixture with MAPbBr3 creating mixed 2D/3D phases and as a passivating thin layer deposited on the top of a 3D perovskite polycrystalline film. We observed a beneficial modulation of the thin film surface, a blue shift in the emission spectrum, and enhanced device performance.

Confinement of MACl guest in 2D ZIF-8 triggers interface and bulk passivation for efficient and UV-stable perovskite solar cells

The MACl@ZIF-8 interlayer plays a bi-functional role in passivating buried interfaces and healing the defects in the bulk phase. As a result, significantly enhanced device performance is obtained with a champion PCE of 22.10%.

Exploring the significance of packing modes and 3D framework sizes and utilizing three chlorine-mediated acceptors and the “like dissolves like” approach for achieving an efficiency over 19%

It revealed the packing arrangement of three representative chlorinated NFAs, showing differences from linear to compact 3D network packing structures, which suggests the evolution direction of NFA materials with gradually enhanced device performance.

Data Visualization Techniques for Medical Device Performance Analytics

This research paper explores various data visualization techniques for analyzing and optimizing the performance of medical devices. As medical devices generate vast amounts of data, effective visualization methods are crucial for interpreting this data to enhance device performance, ensure patient safety, and comply with regulatory standards. This paper examines the principles of data visualization, discusses different visualization techniques, and presents case studies of successful implementations. The paper also includes best practices, potential challenges, and future trends in medical device performance analytics.

The application of gold nanoparticles in biomedicine

In the past few years, nano particles are one of the most popular scientific research fields. It has been widely used in biomedical, optics, electronics and other areas. Gold nanoparticles are quite different from other nanoparticles. Their practical application has a very long history, which has been recorded in ancient Rome. By using their scattering property, gold nanoparticles are added to glass products to make them not only have various colors, but also have photochromic effect. With the development of related fields such as new organic metal chemistry, nanotechnology, and complex research, gold nanoparticles are listed as an important research object in biomedical applications. The shape and size of gold nanoparticles have a direct impact on their optical properties and applications. Therefore, exploring the preparation method to achieve controllable preparation is of great significance for the research of gold nanoparticles. Moreover, the application research of nano gold in biomedicine filed has developed rapidly, especially in recent years. Gold nanoparticles play an increasingly important role in disease detection, targeted therapy, drug detection, enhanced device performance, and imaging. This work mainly discusses the preparation method of gold nanoparticles and its applications in biomedicine field.

Effect of conversion efficiency of electroluminescence and solar cell with change of perovskite thickness

Evidence suggests that the combination of a diode structure with a hybrid organic-inorganic perovskite may give rise to multifunctional device phenomena, such as the high power conversion efficiency of a solar cell and the strong electroluminescence efficiency of a light-emitting diode. This might open the door for the creation of a device with several uses. These multifunctional devices have a limited ability to approach the Shockley-Queisser efficiency limit due to the nonradiative losses that lower the open circuit voltage (Voc) . Here, we investigate and quantify the radiative limit of current carrying capacity in a perovskite solar cell as a function of absorber thickness. We seek to get a deeper understanding of the limiting elements that contribute to a low Voc by developing a link between PCE and EL efficiency over a variety of thicknesses. The efficiency of power conversion increases with increasing perovskite thickness, whereas the efficiency of energy conversion declines. To control light while also minimisingnonradiative losses, it is necessary to consider both of these figures of merit of a solar cell and tie them together. The findings suggest that increasing the efficiency of absorption and emission is critical for enhancing device performance.

Low‐Voltage, High‐Performance, Indium‐Tin‐Zinc‐Oxide Thin‐Film Transistors Based on Dual‐Channel and Anodic‐Oxide

AbstractOxide semiconductor thin‐film transistors (TFTs) with low‐voltage operation, excellent device performance, and bias stability are highly desirable for portable and wearable electronics. Here, the development of low‐voltage indium‐tin‐zinc‐oxide (ITZO) TFTs with excellent device performance and bias stability based on a dual‐channel layer and an anodic‐oxide dielectric layer are reported. An ultra‐thin anodic AlxOy film as a gate dielectric layer is prepared using an anodization process. The dual‐channel layer consists of an oxygen‐uncompensated channel layer and an oxygen‐compensated capping layer. It is confirmed that the dual‐channel structure is effective for enhancing device performance and bias stability in comparison with the single‐channel structure. As a result, the dual‐channel ITZO TFT gated with anodic AlxOy exhibits an effective saturation mobility of 12.56 cm2 Vs−1, a threshold voltage of 0.28 V, a subthreshold swing of 76 mV dec−1, a low‐voltage operation of 1 V, and good operational stability (threshold voltage shift (ΔVTH) < −0.03 V under a negative gate bias stress and ΔVTH < 0.15 under positive gate bias stress of 3600 s). The work shows that the ITZO TFTs, based on a dual‐channel layer and an anodic‐oxide gate dielectric layer, have great potential for low‐power, portable, and wearable electronics.

Research Progresses on Suppressing the Short-Channel Effects of Field-Effect Transistor

Recently, with the continuous miniaturization and integration of microelectronic devices in all fields, the conventional MOSFET structure has suffered from severe short channel effects with continuous downsizing. In order to further improve the electrical properties of Very Large-Scale Integration Circuit (VLSI) and obtain the larger device integration density in circuits, new revolution in MOSFET technology is needed, which involves the innovations of new materials, new technologies, and new device structures. This paper explores device structure innovations in traditional planar transistors, such as the device performance enhancement via the high-κ/metal gate and especially the three-dimensional device structure—FinFET, as well as the subsequent development of gate-all-around FET proved to outperform FinFET. The development of high-performance devices based on new materials has become an imperative direction to break through the current bottleneck of silicon-based technologies. This paper focuses on an overview of transition-mental dichalcogenides and ferroelectric materials, including frontier research and current inadequacies. Based on these new approaches, VLSI manufacturing technology has seen many breakthroughs in recent years, which will successfully extend Moore's Law and further promote the development of emerging technologies in multiple fields.

Modulating Residual Lead Iodide via Functionalized Buried Interface for Efficient and Stable Perovskite Solar Cells

Sufficient lead iodide (PbI2) in perovskite films effectively passivates defects and enhances device performance. However, excess large-grained PbI2 clusters tend to be randomly distributed in the perovskite layer, which mitigate the positive effect of the PbI2. Here, we first modulated the distribution and size of PbI2 clusters by functionalizing the buried interface of 4,4′-diaminodiphenyl sulfone hydroiodide (DDSI2). As a multifunctional modifier, DDSI2 can optimize the energy level of tin oxide (SnO2) and passivate the buried interface defects via −NH3+ and S═O functional groups. Moreover, the hydrogen bonding and coordination between DDSI2 and perovskite retard the crystal growth rate and alleviate the lattice stress, thereby improving the quality of the perovskite and modulating the distribution of PbI2. Consequently, the DDSI2-modified device displays a power conversion efficiency of 24.10% and a storage stability of 1800 h. We demonstrate a unique strategy for the rational control of PbI2 for efficient and stable perovskite solar cells.

Highly Efficient Blue Thermally Activated Delayed Fluorescence Emitters with a Triphenylamine‐Based Macrocyclic Donor

AbstractThis work reports the incorporation of a triphenylamine‐based macrocyclic donor to design new donor‐π‐acceptor‐configured blue thermally activated delayed fluorescence (TADF) emitters. The X‐ray structure analyses manifest the degree of twisted conformations that can be modulated by methyl substituents of the π‐bridge and macrocyclic donor, leading to well‐separated highest occupied natural transition orbital and lowest unoccupied natural transition orbital frontier orbitals, thus sufficiently small singlet–triplet energy difference (ΔEST) for TADF. The theoretical analyses elucidate the structure–property relationship and reveal the beneficial effect of macrocyclic donor on increasing reverse intersystem crossing (RISC) process that can contribute to improved triplet‐upconversion efficiency. The blue device employing c‐NN‐TRZ as emitter gave a maximum external quantum efficiecny (EQEmax) of 26.3% as compared to that (19.1%) of the device using the model compound DPA‐MeTRZ without the macrocyclic donor, suggesting the contribution of macrocyclic donor to enhance device performance. Benefiting from the combined advantages of macrocyclic donor and methyl substituents, the device incorporating c‐NN‐MeTRZ as emitter achieves an outstanding EQEmax of 32.2%, which is attributed to the more horizontally oriented emission dipoles as well as the significantly accelerated RISC rate constant (kRISC) resulting from reduced ΔEST. This work represents a new strategy of designing twisted TADF emitter incorporating macrocyclic donor to achieve highly efficient blue device.

High-efficiency emissive dendritic phosphorescent iridium (III) complex with thermally activated delayed fluorescence molecules as functional light-harvesting moieties

Phosphorescent iridium (III) complexes are considered as competitive candidates for fabricating efficient and stable display and illumination devices by the virtue of excellent exciton utilization. Nevertheless, the high-efficiency phosphorescent emitters available for solution-processed fabrication, are still deemed unsatisfactory for the mainstream industries. In this context, a valid strategy of linking thermally activated delayed fluorescence (TADF) group covalently to phosphorescent iridium (III) complexes was proposed, in which TADF groups function as light-harvesting entities. In this way, the TADF units within the prepared complex TriTADF-Ir(dFppy)3, can effectively transfer energy to the phosphor core and thus boost device performances and reduce efficiency roll-off via alleviating the triplet exciton annihilations. As a result, the photoluminescence quantum yield of TriTADF-Ir(dFppy)3 blend films can reach to nearly 73 %. Thanks to the peripheral TADF dendrons, flexible TriTADF-Ir(dFppy)3 can be employed in fabricating solution-processed phosphorescent organic light-emitting diodes (PhOLEDs) with greenish-blue emission, which achieve external quantum efficiency value over 20 % and maintaining around 16 % at 1000 cd/m2. Overall, this result manifests that the effective utilization of triplet excitons and consequently enhanced device performance of solution-processed PhOLEDs can be accomplished by utilizing TADF molecules as peripheral light-harvesting moieties to construct dendritic phosphorescent emitters.

Dual Function of l‐Phenylalanine as a Modification Layer toward Enhanced Device Performance and Mitigated Lead Leakage in Perovskite Solar Cells

Although perovskite solar cells have achieved great breakthroughs in photoelectric conversion efficiency (PCE), some challenges still need to be addressed before commercialization. Lead leakage is harmful to the environment and many methods are developed to prevent lead leakage; among them, chemical adsorption has proved to be an effective way. Herein, a simple and low‐cost strategy that can enhance the device performance and mitigate the lead leakage by applying l‐phenylalanine in the interface of NiOx/perovskite is reported. The results show that this strategy can improve the morphology and conductivity of the NiOx film, optimize the NiOx/perovskite interface energy level, resulting in an efficient and stable device with a PCE of 19.0%. Furthermore, the interface modification improves the stability of the perovskite film through strong interaction with the perovskite, inhibits the decomposition of the film in water, slows down the process of lead leakage, and protects the environment from lead pollution. The devices maintain 86% initial efficiency for 200 h maximum power point measurement and 94% for 2100 h under nitrogen.

Enhanced Photodynamic of Carriers and Suppressed Charge Recombination Enable Approaching 18% Efficiency in Nonfullerene Organic Solar Cells.

Regulation of the exciton generation, diffusion, and carrier transport, as well as optimization of the non-radiative energy loss could further overcome the power conversion efficiency limitation of organic solar cells. However, the relationship between exciton properties and non-radiative energy loss has seldom been investigated. Herein, taking D18-series devices as the research model, the exciton diffusion length (LD) and hole transfer dynamics can be remarkably improved by the variation of electron-withdrawing halogen and the non-radiative energy loss simultaneously can be suppressed. By combining the analysis results of hole transfer, exciton diffusion, charge separation, and recombination, this work demonstrates that the photo-induced exciton in the chlorinated polymer donor can diffuse to a longer distance within the effective exciton lifetime, suppress the exciton recombination, and enhance device performance. The results define the relationship between the exciton behaviors and non-radiative energy loss and further reveal the significance of controlling the bulk heterojunction with superior photo-physical properties.

Synergistic effects of dual-optical-nanocavity resonance and localized surface plasmons to enhance light absorption in organic solar cells

For organic solar cells, it is a vital issue to effectively confine more light in a thin photoactive layer to guarantee both efficient light absorption and effective collection for photogenerated carriers. Herein, a simple but high-performance composite structure consisting of a front indium tin oxide hemisphere (ITO-HS) array and a silver nanodisk (Ag-ND) array embedded in the photoactive layer is proposed. Benefiting from antireflection and light scattering induced by the ITO-HS array, dual-optical-nanocavity resonances formed by the ITO-HS array, Ag-ND array and Ag electrode, together with the secondary scattering and localized surface plasmons caused by the Ag-ND array, significantly enhanced light absorption can be achieved in a broad range from 300 to 800 nm. Simulation results indicate that the short-circuit current density and power conversion efficiency can be remarkably enhanced by 43.58% and 46.03%, respectively, through introducing the optimal composite light management structure into the normal inverted device architecture of ITO/ZnO/PTB7:PC 71 BM (100 nm)/MoO 3 /Ag, as compared to the control device. Furthermore, this composite light management structure exhibits excellent omnidirectional light confinement. Considering the notable device performance enhancement and the simple structure, this study may provide a guideline for designing and fabricating high-performance light management structures applicable in thin film-based optoelectronic devices. • A simple and efficient light management structure consisting of a front ITO-HS array and an Ag-ND array is proposed. • The enhancement of 43.58% and 46.03% for J sc and PCE is achieved for the device with the optimized light management structure. • Excellent omnidirectional light management is delivered for the proposed optical structure.

Work-function-tunable metal-oxide mesh electrode and novel soluble bipolar host for high-performance solution-processed flexible TADF-OLED

Substantial effort has been dedicated to the development of solution-processed flexible organic light-emitting diodes (sf-OLEDs). However, to simultaneously enhance device performance and ensure stable operation under severe mechanical deformation, highly flexible transparent electrodes and efficient soluble organic emitting materials must be optimized together. Here, highly efficient green-emitting thermally activated delayed fluorescence (TADF) sf-OLEDs were developed using a mesh-structured Ni-doped indium zinc oxide (mNIZO) flexible electrode and a novel soluble bipolar host. The mNIZO electrode had excellent optical, electrical, and mechanical properties. The work function of the mNIZO electrode was engineered through surface doping with Ni without optical and electrical losses. 5-(9 H-Carbazol-9-yl)− 3′-(3,6-di-tert-butyl-9 H-carbazol-9-yl)-[1,1′-biphenyl]− 3-carbonitrile (CzCN-tCz) was synthesized as a soluble host material by incorporating a tert-butyl group into 3,3′-di(carbazol-9-yl)− 5-cyano-1,1′-biphenyl (mCBP-CN). Consequently, the mNIZO-based TADF sf-OLED with CzCN-tCz had a maximum external quantum efficiency of 21.0 % on a poly(ethylene 2,6-naphthalate) substrate, and 82 % of the initial luminance was maintained under severe mechanical stress, which is attributable to the high deformability of the mNIZO electrode. The proposed framework is expected to facilitate the design of high-performance cost-effective flexible displays with various forms through a simple process.

Photo-induced charge transfer in composition-tuned halide perovskite nanocrystals with quinone and its impact on conduction current

A facile interfacial charge transfer (CT) with a reduced inter-layer energy band regulates the charge transport mechanism in any optoelectronic device. The enhancement in semiconductor-based device performance often demands improved CT dynamics and collection of free carriers with reduced charge recombination. In this work, we present a detailed inspection of the photo-induced CT between inorganic lead halide perovskite nanocrystals (PNCs) with varied compositions and their consequence on the charge transport process. The superior CT rate in mixed halide CsPbBr2Cl PNCs with naphthoquinone (NPQ) is revealed when compared with the parent CsPbBr3 PNCs and its anion-exchanged counterpart CsPbCl3. The glimpses of hole transfer contribution along with electron transfer are detected for CsPbBr2Cl with superior CT efficiency. The enhanced conduction current after the insertion of NPQ into the PNCs with a reduced hysteresis suggests an improved charge transport in the fabricated device compared to the pristine PNCs. These findings can contribute to a better understanding of multiple ways of engineering optoelectronic devices to boost performance and efficiencies and the concurrent role of the CT process in the conduction mechanism.

Theoretical study of perovskite solar cell for enhancement of device performance using SCAPS-1D

Perovskite solar cells are a pioneering photovoltaic technology that has significantly improved performance in current years. The fundamental n-i-p planar heterojunction structure of solar cells is structured and simulated in the present work. The device configuration Glass/ITO/WS2/CH3NH3PbI3/P3HT/Au was investigated using the Solar Cell Capacitance Simulator (SCAPS-1D) program. To increase the performance of the photovoltaic solar cell thickness, bandgap, doping concentration and temperature have been varied. Further, using the optimal value of the different parameters, the performance of the photo-voltaic device such as power conversion efficiency (PCE) and Fill Factor (FF) are obtained as 27.02%, and 85.44%, respectively. Also, Open-circuit Voltage (VOC) of 1.46 V and Short-circuit current density (JSC) of 21.56 mA cm−2 were achieved. The influence of donor concentrations has been studied by varying its value from 1 × 10−12 cm−3 to 1 × 10−20 cm−3 for the proposed device. Thus, using different charge transport materials, the power convergence efficiency of the perovskite solar cell has been enhanced. Our simulation study reveals that the proposed configuration could be used to fabricate a device for the improvement of the efficient perovskite solar cell.