Microelectronic Devices Research Articles

High-quality silicon-based perovskite photodetectors with the detectivity exceeding 7.5 × 1013 Jones

Considering the advantages of silicon-based microelectronic devices and the excellent photophysical properties of halide perovskites, silicon-based perovskites are expected to demonstrate great potential for application in the field of optoelectronic devices. In this paper, an antisolvent-assisted strategy is used to prepare MAPbBr3 perovskite microcrystals on silicon substrates, and dense, continuous, and smooth perovskite microcrystal thick films are further obtained after the hot-press treatment. Finally, an n-Si/perovskite thick film/carbon structure device is constructed which shows excellent photoresponsive performance with a responsivity of 11.7 A/W, a detectivity of 7.57 × 1013 Jones, and a linear dynamic range of 147 dB at 405 nm with a 0.5 V bias. Moreover, the device can respond to the light with its light intensity of as low as 2.14 × 10−6 mW cm−2, demonstrating excellent weak-light detection performance. This integration of silicon with the halide perovskites shows tremendous potential for applications in the field of semiconductor devices.

Mini-review on laser-induced nanoparticle heating and melting

The development of various nanomaterials production technologies has led to the possibility of producing nanoparticles (NPs) and nanostructures, which can find a wide range of applications, from the fabrication of microelectronic devices to the improvement of material properties and the treatment of cancer. The unique characteristics of nanoparticles are primarily due to their small size, which makes size control important in their preparation. Modification of nanoparticles by laser irradiation and obtaining desired nanoparticle properties is a promising approach because of its ease of implementation. The purpose of this review is to analyze the works devoted to the study of laser-induced heating and melting of nanoparticles, to collect information and evaluate the results of using this method for functionalization and modification of metallic nanoparticles, and to discuss promising directions for the use of this technique.

The Low-Temperature Thermal Conductivity of Epoxy Resin Composites Enhanced by Graphene and Modified Alumina Hybrid Fillers

In recent years, polymer/ceramic composites with high thermal conductivity have been widely used in microelectronic devices, superconducting magnets and aviation, and further improving their thermal conductivity is a great challenge. In this work, spherical alumina nanoparticles were modified with 3-aminopropyltriethoxy-silane (APTES) successfully. Furthermore, the modified Al2O3(M-Al2O3)/Epoxy(EP) and Graphene(Gr)/M-Al2O3/EP composites were prepared and their properties were tested in the temperature range of 70 K-300 K. The results showed that the thermal conductivity of the composite with 1 wt% Gr and 60 wt% M-Al2O3 hybrid filler is 15 times higher than that of pure epoxy at 70 K, which indicates its application prospect in thermal interface materials.

Strain-Induced Tunable Enhancement of Piezoelectricity in a Novel Molecular Multiferroic Material.

Multiferroics are appealing because of application potentials in data storage devices, sensors, transducers, and energy harvesters. Molecular multiferroics emerge as a promising alternative to inorganic multiferroics due to flexibility, light weight, low toxicity, solution processing, structural diversity, and chemical tunability. While researches have predominantly focused on perovskite structures, studies on molecular ionic multiferroics remain relatively limited. It is urgent to creatively build a novel platform for studying and developing the coupling and interaction between the stress, electricity, and magnetism. Knowing this, the work focuses on a novel organic-inorganic hybrid multiferroic N-ethyl-N-(fluoromethyl)-N-methylethylammonium tetrabromoferrate (III) showing coexisting magnetic and electric orderings. It undergoes antiferromagnetic, ferroelectric, and ferroelastic transitions. Notably, under a strain of 2.0%, the piezoelectric response increases tenfold, and the coercive field of ferroelectric polarization is reduced by half. The strain-induced enhancement of piezoelectricity is rarely reported in molecular multiferroics. Density functional theory is employed to predict that the mechanism of the large piezoelectric response under strain engineering is related to the cation rotation and phase switching between the stable phase and an energetically competitive metastable phase. This study creates a new paradigm to develop molecular multiferroics and future microelectronic devices for energy conversion.

Vibrational coupling-based multilayer flexible triboelectric nanogenerator for wide-amplitude omnidirectional wave energy harvesting

Wave energy harvesters are viewed as potential foundations for self-powered wireless sensor devices. In this study, a multilayer flexible triboelectric nanogenerator (MFLU-TENG) is proposed and evaluated, which combines the stretching properties of springs and the deformation properties of flexible materials to enable wide-wavelength energy harvesting. It captures wave energy even at very low amplitudes, requiring a minimum wave amplitude of 5 cm for energy recovery. The study explores how geometric parameters of the MFLU-TENG affect vibration behavior and output performance. Optimal performance is achieved when varying the thickness of the PETG cushioning layer, resulting in a peak power density of up to 7.7 mW/m2. Three MFLU-TENGs connected in parallel successfully power 15 LEDs. And four parallel groups of MFLU-TENGs charged a 100µF capacitor to 5.3 V in 198 s and successfully powered the temperature and humidity sensor. And the MFLU-TENGs charge the 100uf capacitor to 4.0v and power the clock in 153 s. These findings underscore the MFLU-TENG’s potential as a cost-effective and efficient wave energy harvesting device, using renewable wave energy to power sensors or microelectronic devices in the Internet of Things.

Anti-plane Yoffe-type crack in flexoelectric material

This work investigates the deformation and polarization fields around a finite anti-plane shear (mode III) crack growing dynamically under steady-state conditions. The leading tip of this finite crack breaks the material while the trailing tip heals it. This fast moving finite crack (referred to as a rupture “pulse” in the geophysics literature) propagates with a constant velocity and with the mechanical and the electrical fields that remain invariant with respect to an observer moving with the crack-tips. This problem belongs to the first type of steady state crack growth problems according to the classification of Freund. The “prototype” problem which refers to an isotropic, body subjected to fracture under tensile loading was first proposed and solved by Yoffe, while finite cracks (or shear pulses) were also analyzed by Freund and by Rice. In the above cases the material was assumed to be linear elastic. Our analysis extends these studies to flexoelectric materials, and it is both theoretical and numerical. It discusses the asymptotic structure of the crack-tip displacement and the polarization fields; it calculates the dynamic energy release rate and presents their dependence on crack-tip velocity. Comparisons are made to the available, classical, elasto-dynamic solutions and to the static case. The influence of the electrical properties of the material on strengthening is also analyzed. Dynamic fracture of flexoelectric materials is of relevance to both the study of earthquake source mechanics and to the analysis of the reliability of micro-electronic devices. This is because both rocks and ceramics are flexoelectric. Indeed, during earthquake rupture processes, dynamic, in-plane shear (Mode-II) and out of plane shear (Mode-III), cracks propagate along faults and exhibit both mechanical and electrical polarization signatures. At an entirely different length scale, flexoelectric ceramics are currently used as sensors and transducers and can experience dynamic shear failure along interfaces when subjected to dynamic loading (e.g. impact.). Failure by dynamic fracture can be detrimental to both their mechanical reliability and electrical functionality.

Atomic-scale insights into the microstructure and interface evolution mechanism of copper/tantalum nanofilms during ultra-precision grinding

The copper (Cu)/tantalum (Ta) nanofilms are the vital component in the through silicon via (TSV) wafer. However, the current lack of research on the ultra-precision machining of Cu/Ta nanofilms limits the development of TSV-based 3D integration technologies. In this work, molecular dynamics simulations are conducted to reveal the microstructure and interface evolution mechanism of Cu/Ta nanofilms during nano-grinding under various grinding depths. The results show that the material removal mode differs between the Cu and Ta layers, and the thickness of the subsurface damage layer of the Cu layer is greater than that of the Ta layer. The Cu/Ta interface is well stabilized, and small amounts of micro-defects appear only at larger grinding depths after grinding. The lattice mismatch of the constituent layers and the hindering role by the interface lead to stress concentration at the interface, and it is more obvious with increasing grinding depth. Nevertheless, there is a significant stress release after grinding. Our computations indicate that the competition between the evolution of interfacial structures and discrepancies in the physical properties of constituent layers leads to an increase in grinding forces at the interface. Furthermore, the heat transfer is obstructed by the Cu/Ta interface. This study provides valuable insights into the grinding mechanisms of Cu/Ta nanofilms, which is conducive to further improving the manufacturing process of the TSV wafer and enhancing the performance of microelectronic devices.

Three-dimensional bioconvection in a nanofluid film over a wedge surface with entropy generation and nonlinear radiation: A revised Buongiorno model

ABSTRACT The advances in the field of nanotechnology tends to improve the rate of heat extraction and transmission from foreseeable causes and has fascinated researchers and scientists. Furthermore, nanofluids are having a useful impact on various fields such as nuclear industries, powered lasers, chilling of microelectronic devices, solar energy capture, transformers oil cooling, and in cancer diagnosis. Hence, magnetohydrodynamic (MHD) three-dimensional bioconvective flow of nanofluid accommodating gyrotactic microorganisms over a wedge surface with zero nanoparticles mass flux boundary conditions is studied, using large Reynolds number approximation. The additional novelty of the study is the implementation of the revised Buongiorno model, which deliberates the effects of thermo-migration and Brownian diffusion of nanoparticles, together with passive control of nanoparticles fraction on the wedge surface. The self-similar form of conservation equations of energy, nanoparticle fraction, gyrotactic microorganisms, and momentum are handled numerically. T The results of the Blasius and the Hiemenz flows are retrieved as special cases of the model. It was found that the temperature of the nanofluid increases considerably when considering the nonlinear thermal radiation compared to the linear radiant heat. Increasing the strength of the Brownian diffusion increases the heat transport but reduces the mass transport.

Conformally Printed Additively Manufactured RF Demonstrator for Circuit Compaction

Abstract Recently, there has been interest in applying Additive Manufacturing (AM) to RF and Microwave applications, especially in packaging of microelectronic devices. Additive packaging offers advantages of expanded functionality in restricted volume, through miniature, low-SWaP-C sensors, allowing for non-traditional form factors. In this work, design, fabrication, and characterization of a non-planar multi-material MMIC structure is presented to demonstrate significant footprint reduction and circuit compaction. Performance of a non-planar passive RF device and details of planar to non-planar AM connections for characterization of the transitions will be demonstrated. The work will present details of the design and fabrication of the non-planar structure, optimization of the process parameters for the Optomec 5-axis Aerosol Jet Printer for multi-material printing, and the results of the characterization and testing. RF measurements were conducted to demonstrate the functionality of the developed non-planar circuit and compared with simulations which showed good agreement. The results of this work show that fully additive approach is feasible for non-planar circuits, which will allow for footprint reduction, weight reduction, and achievement of novel form factors that are critical for microwave applications.

1D/2D Heterostructures: Synthesis and Application in Photodetectors and Sensors

Two-dimensional (2D) semiconductor components have excellent physical attributes, such as excellent mechanical ductility, high mobility, low dielectric constant, and tunable bandgap, which have attracted much attention to the fields of flexible devices, optoelectronic conversion, and microelectronic devices. Additionally, one-dimensional (1D) semiconductor materials with unique physical attributes, such as high surface area and mechanical potency, show great potential in many applications. However, isolated 1D and 2D materials often do not meet the demand for multifunctionality. Therefore, more functionality is achieved by reconstructing new composite structures from 1D and 2D materials, and according to the current study, it has been demonstrated that hybrid dimensional integration yields a significant enhancement in performance and functionality, which is widely promising in the field of constructing novel electronic and optoelectronic nanodevices. In this review, we first briefly introduce the preparation methods of 1D materials, 2D materials, and 1D/2D heterostructures, as well as their advantages and limitations. The applications of 1D/2D heterostructures in photodetectors, gas sensors, pressure and strain sensors, as well as photoelectrical synapses and biosensors are then discussed, along with the opportunities and challenges of their current applications. Finally, the outlook of the emerging field of 1D/2D heterojunction structures is given.

Crystallite size and phase purity in Pb1-xSrxTiO3 ferroelectric perovskites for biomedical applications via controlled sintering

ABSTRACT Lead strontium titanate (Pb1-xSrx)TiO3 (PST) is a ferroelectric perovskite material with tunable properties, including Curie temperature, spontaneous polarization, and high dielectric permittivity, making it promising for advanced biomedical applications, such as biosensors, bioimaging, and light-activated therapeutics. This study investigates the effect of varying sintering temperatures on the crystallite size and phase purity of PST, aiming to optimize its performance for biomedical devices. PbCO3, SrCO3, and TiO2 powders were processed via ball milling for 58 hours, followed by sintering at temperatures ranging from 500°C to 1100°C. Laser diffraction particle size analysis and X-ray diffraction (XRD) were used to assess the particle size and crystal phase transformations. The results demonstrate that higher sintering temperatures improve the PST phase composition, reducing impurities and enhancing crystallite growth. The most significant crystal growth was observed at 900°C, while the optimal phase purity and crystallite size (91.5 nm) were achieved at 1100°C, producing 100% single-phase PST. These findings emphasize the critical role of sintering temperature in tailoring PST’s properties, enhancing its suitability for electronic and microelectronic biomedical devices. Controlled sintering in perovskite materials opens new pathways for their application in medical diagnostics and therapeutic technologies.

Triboelectric nanogenerator based on silane-coupled LTA/PDMS for physiological monitoring and biomechanical energy harvesting

Energy harvesting from ambient sources present in the environment is essential to replace traditional energy sources. These strategies can diversify the energy sources, reduce maintenance, lower costs, and provide near-perpetual operation of the devices. In this work, a triboelectric nanogenerator (TENG) based on silane-coupled Linde type A/polydimethylsiloxane (LTA/PDMS) is developed for harsh environmental conditions. The silane-coupled LTA/PDMS-based TENG can produce a high output power density of 42.6 µW/cm2 at a load resistance of 10 MΩ and operates at an open-circuit voltage of 120 V and a short-circuit current of 15 µA under a damping frequency of 14 Hz. Furthermore, the device shows ultra-robust and stable cyclic repeatability for more than 30 k cycles. The fabricated TENG is used for the physiological monitoring and charging of commercial capacitors to drive low-power electronic devices. Hence, these results suggest that the silane-coupled LTA/PDMS approach can be used to fabricate ultra-robust TENGs for harsh environmental conditions and also provides an effective path toward wearable self-powered microelectronic devices.

Loose particle Detection: The optimal detection condition and weak loose particle impulse extraction

To achieve effective detection of loose particles within small cavities in microelectronic devices, this paper proposes the optimal detection conditions of loose particles in ceramic packaging for microelectronic devices based on simulation, and presents a method for weak signal reconstruction using weighted sparse representation. To address the challenge of ineffective detection of loose particles under recommended vibration conditions, a particle-cavity collision dynamics model is established. Subsequently, the detection laws of loose particles under different accelerations, frequencies, and cavity heights are studied through simulation, leading to the establishment of optimal detection conditions for microelectronic devices with varying cavity heights. To address the issue of weak impulses being submerged in background noise under optimal detection conditions, sparse representation is utilized for signal reconstruction. First, a Laplace wavelet dictionary is constructed according to the impulse characteristics. Second, the generalized minimax-concave (GMC) penalty function is applied as a sparse regularization term to preserve signal amplitude. Meanwhile, a weight matrix based on kurtosis and singular value is designed to threshold sparse coefficients. The results demonstrate that the proposed optimal detection conditions and signal reconstruction method effectively detect loose particles. Compared with other algorithms, the proposed method reduces background noise in the particle impact noise detection (PIND) signals while maintaining impulse amplitude; it also improves signal reconstruction accuracy and offers valuable insights into effective loose particle detection in microelectronic packaging devices.

3D Binder-Free Mo@CoO Electrodes Directly Manufactured in One Step via Electric Discharge Machining for In-Plane Microsupercapacitor Application

Cobalt oxide-based in-plane microsupercapacitors (IPMSCs) stand out as a favorable choice for various applications in energy sources for the Internet of Things (IoT) and other microelectronic devices due to their abundant natural resources and high theoretical specific capacitance. However, the low electronic conductivity of cobalt oxide greatly hinders its further application in energy storage devices. Herein, a new manufacturing method of electric discharging machining (EDM), which is simple, safe, efficient, and environment-friendly, has been developed for synthesizing Mo-doped and oxygen-vacancy-enriched Co-CoO (Mo@Co-CoO) integrated microelectrodes for efficiently constructing Mo@Co-CoO IPMSCs with customized structures in a single step for the first time. The Mo@Co-CoO IPMSCs with three loops (IPMSCs3) exhibited a maximum areal capacitance of 30.4 mF cm−2 at 2 mV s−1. Moreover, the Mo@Co-CoO IPMSCs3 showed good capacitive behavior at a super-high scanning rate of 100 V s−1, which is around 500–1000 times higher than most reported CoO-based electrodes. It is important to note that the IPMSCs were fabricated using a one-step EDM process without any assistance of other material processing techniques, toxic chemicals, low conductivity binders, exceptional current collectors, and conductive fillers. This novel fabrication method developed in this research opens a new avenue to simplify material synthesis, providing a novel way for realizing intelligent, digital, and green manufacturing of various metal oxide materials, microelectrodes, and microdevices.

Investigation of hydrothermal characteristics and entropy generation in a microchannel heat sink with elliptical fins

Abstract As the integration of microelectronic devices continues to increase, thermal management issues become increasingly prominent. Microchannel heat sinks are effective for heat dissipation in high heat flux microelectronic devices. This study designs five elliptical finned microchannel heat sinks with different aspect ratios (γ) while maintaining a constant elliptical area to enhance heat transfer performance. The values of γ are 0.74, 0.86, 1, 1.17, and 1.35, respectively. Over the Reynolds number (Re) range of 293 to 740, the hydrothermal characteristics and entropy generation of the microchannels with elliptical fins (MC-EFs) are investigated through numerical simulations. The thermal enhancement mechanism of MC-EFs is analyzed via flow, temperature, and pressure fields. The optimal γ value is determined by maximizing the overall performance factor (OPF) and minimizing the augmentation entropy generation number (Ns,a). Results indicate that introducing elliptical fins in the straight microchannel (SMC) significantly improves heat dissipation. An increase in γ enhances thermal performance but also raises flow resistance. Specifically, when γ increases from 0.74 to 1.35, the Nusselt number (Nu) improves by 10.71%-25.64%, and the friction coefficient (f) increases by 30.92%-57.27%. Overall, at Re = 740, the OPF of the MC-EF with γ = 1.35 reaches a maximum of 1.285, and at Re = 597, the Ns,a for this configuration is minimized to 0.578. These findings provide valuable insights for effective thermal management in microelectronic devices.

Stretchable Wearable Wireless Bioelectronics Using All Printed Pressure Sensors and Strain Gauges

AbstractThe sense of touch and perception of hand motion form an essential part of the somatic sensory system. Although piezoelectric sensors demonstrate high sensitivity and linearity, they are traditionally not employed for electronic skins because of their limited stretchability. Here, a printed, skin‐conformal, electronic system consisting of stretchable piezoelectric pressure sensors and carbon nanotube strain gauges capable of identifying tactile sensations and joint movements on the hand is introduced. The pressure sensor demonstrates both high sensitivity (19.9 mV kPa−1) and linearity (0.1–1000 kPa) while being reliably stretchable to above 15%. To complement the pressure sensing functionality, a strain gauge is fabricated in a rapid stamp printing process and designed to demonstrate excellent mechanical reliability with up to 70% strain and high sensitivity (36.5‐gauge factor). These sensors can seamlessly conform to numerous anatomical regions and cover wide areas of the skin, making them ideal for deployment in an electronic skin. Finally, the sensors are integrated with a flexible microelectronic device to demonstrate their functionality in human touch and prosthetic hand applications.

Efficient Multifunctional Modification of Commercial Carbon Fiber through Tailored Carbon Layer Structure

Polyacrylonitrile-based commercial carbon fibers (CFs) have garnered significant attention in mechanical applications because of their exceptional mechanical properties. However, their functional versatility relies heavily on the structural intricacies of duplex carbon layers. Current modification approaches, though effective, are encumbered by complexity and cost, limiting widespread adoption across diverse fields. We herein present a straightforward modification strategy centered on regulating carbon layers to unlock the multifunctional potential of CFs. Our method leverages two common anions, Cl− and SO42−, to facilitate oxidation reactions in CFs under robust alkali and high voltage conditions. Cl− effectively activates carbon layers, while SO42− facilitates layer movement. The electrocatalytic activities of the resultant CFs are enhanced, with state-of-the-art performance as supercapacitors and exceptional stability. Moreover, our approach achieves a groundbreaking milestone by bending and fusing CFs without using binders. This breakthrough can reduce the manufacturing costs of CF-based products. It also facilitates the development of novel microelectronic devices.

Direct Observations of Spontaneous In-Plane Electronic Polarization in 2D Te Films.

Single-element polarization in low dimensions is fascinating for constructing next-generation nanoelectronics with multiple functionalities, yet remains difficult to access with satisfactory performance. Here, spectroscopic evidences are presented for the spontaneous electronic polarization in tellurium (Te) films thinned down to bilayer, characterized by low-temperature scanning tunneling microscopy/spectroscopy. The unique chiral structure and centrosymmetry-breaking character in 2DTe gives rise to sizable in-plane polarization with accumulated charges, which is demonstrated by the reversed band-bending trends at opposite polarization edges in spatially resolved spectra and conductance mappings. The polarity of charges exhibits intriguing influence on imaging the moiré superlattice at the Te-graphene interface. Moreover, the plain spontaneous polarization robustly exists for various film thicknesses, and can universally preserve against different epitaxial substrates. The experimental validations of considerable electronic polarization in Te multilayers thus provide a realistic platform for promisingly facilitating reliable applications in microelectronic devices.

Dimerized Non-Fullerene Acceptor-based organic photovoltaics for Round-the-Clock functioning

Organic photovoltaics (OPVs) have emerged as a key sustainable energy technology capable of efficiently generating electricity from both direct sunlight and low-intensity indoor lighting. Despite ongoing research to improve their performance, limited efforts have been undertaken to develop OPVs that can operate consistently (24/7/365) under versatile lighting conditions. For effective utilization, OPVs must demonstrate efficient operation under both outdoor and indoor illumination conditions, generating sufficient electrical power to drive microelectronic devices. Low-bandgap non-fullerene acceptors (NFAs) in OPVs are limited by low open-circuit voltage (VOC) under indoor lighting, restricting their performance. While high-bandgap NFAs can improve indoor power-conversion efficiency (PCE) by elevating VOC, they may often reduce outdoor performance owing to reduced light harvesting. Thus, we developed OPVs using the oligomeric dimerized NFA DYBO, which simultaneously achieved an excellent PCE of 16.7 % under simulated solar illumination and a remarkable maximum power output density (Pmax) of 0.079 and 0.396 mW/cm2 under a 5,200 K LED and halogen lamp (1000 lx), respectively, attributed to elevated VOC and reduced short-circuit current density (JSC) losses. The optimized OPVs demonstrated PCEs nearly equivalent to those of the current state-of-the-art under indoor illumination, with a remarkable Pmax capable of autonomously powering a variety of microelectronic devices.

Effects of ultrasound on bubble dynamic behavior of flow boiling in microchannel

Bubble dynamics is paramount in comprehending the heat transfer mechanisms of flow boiling in the microchannel within ultrasonic field, which is regarded as a promising method to confront challenges of thermal management posed by microelectronic devices. Nevertheless, the impact of ultrasound on bubble behaviors and its underlying mechanisms remain largely unexplored. This study first delves into the effect of ultrasonic parameters on bubble dynamic behaviors and associated mechanisms, subsequently further analyzing the forces acting on bubbles through the constructed force model. The findings suggest that although growth force serves as the significant resistance, the primary Bjerknes force dominates the rapid detachment of bubbles. The secondary Bjerknes force results in the bubble only sliding along the bottom wall rather than lifting off. Furthermore, the elevated ultrasonic pressure amplitude resulting from augmenting ultrasonic power induces a substantial increase in the critical detachment diameter and growth rate by 55.49% and 59.42%, respectively. The enhanced primary Bjerknes force, attributed to the rise in ultrasonic frequency, leads to a 71.42% increase in sliding velocity and a 46.45% reduction in growth time. The positive impacts arising from ultrasonic power and frequency are anticipated to notably enhance the thermal performance of microchannels. Besides, surface tension acts as the resistance and diminishes slightly with an augmentation of the boiling number, resulting in a moderate variation in sliding velocity and growth time.