Device Performance Research Articles

In vitro photocurrents from spinach thylakoids following Mn depletion and Mn-cluster reconstitution

Biohybrid devices that generate an electrical signal under the influence of light due to photochemical reactions in photosynthetic pigment-protein complexes have many prospects. On the one hand, the oxygen-evolving complex of photosystem II allows the use of ubiquitous water as a source of electrons for photoinduced electron transfer in such devices; on the other hand, it is the most vulnerable part of the photosynthetic apparatus. From the perspective of sustainable operation of bio-based hybrid devices, it is helpful to analyze how removing or modifying the Mn cluster will affect the performance of the bio-hybrid device. This work analyzed photocurrent generation in a liquid three-electrode solar cell based on manganese-depleted and reactivated thylakoid membranes. Membranes lacking Mn could not produce any significant photocurrent until manganese chloride was added. After adding MnCl2, the cell could produce current when exposed to light. This current was about a few percent from cells with intact thylakoid membranes. However, the photoactivation procedure made it possible to restore up to 75 % of the photocurrent of cells based on intact thylakoid membranes. The main objective of this work is to answer the question about the possibility of photocurrent generation in a biohybrid system based on thylakoid membranes using artificial analogs of the native oxygen-evolving complex. Photoactivation with manganese chloride is the simplest way to obtain preparations devoid of the native Mn cluster, but capable of oxidizing water.

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.

Core-shell nanorods film of p-CuZnS/n-TiO2 with boosting interfacial charge separation for sensitive photoelectrochemical photodetector

Copper zinc sulphide (CZS) due to high conductivity, fast photoresponse and good stability has attracted rising attention in optoelectronic field. Constructing heterojunctions with rational energy bands alignment can accelerate carrier separation to improve the performance of CZS-based photoelectric device. Herein, p-CZS/n-TiO2 core-shell nanorods heterojunction film was successfully fabricated for the first time. CZS nanoparticles (NPs) were directly loaded on the surface of TiO2 nanorods (NRs) through a simple chemical bath deposition. Photoelectrochemical (PEC) photodetector based on CZS/TiO2 composite film was designed and interfacial charge kinetics has also been investigated. The CZS/TiO2 PEC device exhibits fast response speed of 95/56 ms, high responsivity of 7.1 mA W-1 and detectivity of 5.6 × 1012 Jones at a bias voltage of 1 V. The light on/off ratio of self-powered CZS/TiO2 PEC device achieves 5.6 × 103, nearly 30.4 times higher than bare CZS PEC device. Furthermore, the photodetection performance of the CZS/TiO2 PEC device can be effectively regulated by light power density and environment conditions, promoting its adaptability in multifarious practical applications. The findings suggest that CZS/TiO2 heterostructure film devices have great potential for high-performance and energy-efficient PEC photodetectors.

Performance of consumer wrist-worn type sleep tracking devices compared to polysomnography: a meta-analysis.

The use of sleep tracking devices is increasing as people become more aware of the importance of sleep and interested in monitoring their patterns. With many devices on the market, we conducted a meta-analysis comparing sleep-scoring data from consumer wrist-worn sleep tracking devices with polysomnography to validate the accuracy of devices. We retrieved studies from the databases of SCOPUS, EMBASE, Cochrane Library, PubMed, Web of Science, and KoreaMed, and OVID Medline up to March 2024. We compared personal data about participants and information on objective sleep parameters. From 24 studies, data of 798 patient using Fitbit, Jawbone, myCadian watch, WHOOP strap, Garmin, Basis B1, Zulu Watch, Huami Arc, E4 wristband, Fatigue Science Readiband, Apple Watch, or Xiaomi Mi Band 5 were analyzed. There were significant differences in total sleep time {mean difference (MD) -16.854, 95% confidence interval (CI) [-26.332; -7.375]}, sleep efficiency (MD -4.691, 95% CI [-7.079; -2.302]), sleep latency (MD 2.574, 95% CI [0.606; 4.542]), and wake after sleep onset (MD 13.255, 95% CI [4.522; 21.988]) between all consumer sleep tracking devices and polysomnography. In subgroup analysis, there was no significant difference of wake after sleep onset between Fitbit and polysomnography. There was also no significant difference sleep latency between other devices and polysomnography. Fitbit measured sleep latency longer than other devices, and other devices measured wake after sleep onset longer. Based on Begg and Egger's test, there was no publication bias in total sleep time and sleep efficiency. Wrist-worn sleep tracking devices, while popular, are not as reliable as polysomnography in measuring key sleep parameters like total sleep time, sleep efficiency, and sleep latency. Physicians and consumers should be aware of their limitations and interpret results carefully, though they can still be useful for tracking general sleep patterns. Further improvements and clinical studies are needed to enhance their accuracy.

Research on damage mechanism of casing based on fluid-structure coupling and perforation performance of new perforation device

Research on damage mechanism of casing based on fluid-structure coupling and perforation performance of new perforation device

Effect of NO annealing on radiation detection performance of Ni/SiO2/4H-SiC MOS capacitors

In this study, Ni/SiO2/4H-SiC metal-oxide-semiconductor (MOS) devices were fabricated, achieving high-energy resolution for alpha particle radiation detection. The SiO2/4H-SiC interface was treated with two different methods: i) annealing in N2 environment, ii) annealing in NO environment. Devices manufactured using the former method show lower dark currents than the latter. This difference is due to a decrease in trap density at the SiO2/4H-SiC interface caused by NO annealing, resulting in a higher barrier height for the device. The NO-30 exhibited a much higher energy resolution of 0.46%@5486 keV compared to 0.95%@5486 keV observed in N2-30, despite both devices exhibiting good energy linearity in response to alpha particles. The SiO2/4H-SiC interface trap density revealed a significant decrease after NO treatment, indicating NO treatment can effectively improve the electrical performance of 4H-SiC MOS devices. CCE analysis showed the NO-30 had a lower surface recombination field (13000 V/cm) compared to N2-30 (35000 V/cm), which improves the charge collection efficiency and energy resolution. This study provides a practical approach for enhancing the energy resolution of 4H-SiC MOS detectors.

Machine learning analysis for heat transfer enhancement in nano-encapsulated phase change materials within L-shaped enclosure with heated blocks

Phase change materials(PCMs) are crucial to energy storage systems due to their enhanced thermal properties. They significantly boost energy efficiency and promote sustainability. Nevertheless, the low thermal conductivity of PCMs presents a significant challenge, which is addressed by utilizing nano-encapsulation to enhance energy efficiency in energy storage systems. Motivated by this, the current study conducts a theoretical investigation to explore the heat transfer characteristics in a buoyancy-driven Nano-Encapsulated Phase Change Materials(NEPCM) nanofluid within an L-shaped porous enclosure with the impacts of a heated block and magnetic field. Furthermore, the fusion temperature plays a crucial role in initiating phase change in NEPCM, thereby impacting the heat transfer process. Hence, identifying the optimal fusion temperature is essential. To accomplish this, a machine learning approach was employed to identify the ideal fusion temperature. A dataset of 160 data points across four different fusion temperature values was used in this analysis. Additionally, the machine learning model analyzed how variations in fusion temperatures impact physical parameters. An in-house Matlab code is utilized to solve the dimensionless fluid transport equations employing the finite difference method. The results indicate that increasing the nanoparticle volume fraction significantly enhances the heat transfer rate across all physical parameters. Specifically, under higher thermal buoyancy force, increasing the volume fraction from 1% to 5% results in a 90.04% increase in the heat transfer rate. The numerical analysis demonstrates that heat transfer rates improve significantly when the fusion temperature is adjusted to 0.5, a result further validated by machine learning techniques. At this temperature, thermal buoyancy force increases by 0.98% and 2.68% compared to values of 0.1 and 0.9, respectively, while the Stefan number shows increases of 159.42% and 87.48% under these conditions; thereby, the heat transfer rate increases at this value. This computational study provides important insights into the significance of fusion temperature, emphasizing the need to determine its optimal value for improving heat transfer. Identifying this optimal value can enhance the efficiency of thermal energy storage systems and improve cooling performance in electronic devices.

Improving the performance of IoT devices that use Wi-Fi

<p>Providing quality service to users of the internet of things (IoT) entails addressing two crucial aspects: one related to security and the other concerning the limited resources of IoT devices. We will face a challenge while using timesensitive applications within a network that utilizes a high-performance Wi-Fi technology with exceeding energy consumption. Due to this research challenge, we propose a new algorithm, IoT-quality of service (QoS), designed to achieve a true balance between enhancing the security aspects of IoT devices and improving network-hardware performance. Thus, the algorithm efficiently manages the limited energy resources by monitoring energy levels, communication quality, and queuing delay at access points. This is accomplished by utilizing a streamlined identity management system capable of achieving authentication and access authorization with reduced loading for IoT devices. The research hypothesis underwent validation through a comparative analysis of its performance against the conventional model of a Wi-Fi-based IoT device. This evaluation was conducted utilizing the NS3 simulator and was based on a predetermined set of parameters influencing the examined performance metrics, including power consumption, throughput, delay, and response time. The findings exposed the superiority of the proposed algorithm.</p>

Coherent Epitaxy of HfxZr1-xO2 Thin Films by High-pressure Magnetron Sputtering

Due to remarkable high-k and ferroelectric properties in CMOS devices, the study of crystalline HfxZr1-xO2 (HZO) thin films has attracted tremendous interest recently. However, up to now, the epitaxial growth of HZO films has only been achieved by pulse laser deposition, a technique scarcely utilized in CMOS devices. Therefore, developing appropriate epitaxial methods of HZO films (such as sputtering) is fairly necessary, but a challenge at present. In this work, high-quality single-crystalline HZO films were synthesized by high-pressure magnetron sputtering. The epitaxial growth of HZO films on yttria-stabilized zirconia (YSZ) substrate was demonstrated by a combination of high-resolution X-ray diffraction, atom force microscope, and scanning transmission electron microscope. In addition, good insulating characteristics were obtained by replacing insulating substrates with conductive substrates as electrodes. Our results provide a novel way for the epitaxial growth of the single-crystalline structure of HZO thin films towards the high performance of high-k and ferroelectric devices.

Electro-osmotic flow and heat transfer in Jeffery fluid: A multi-membrane microchannel model

Microscale heat transfer is vital for the performance of smart thermal devices like heat sinks, thermosyphons, and microheat pipes. This study introduces a biothermal pumping flow model based on a multi-membrane pumping mechanism that leverages microscale heat transfer. The model describes rhythmic contraction and relaxation of membranes, combined with electro-osmosis in Jeffery fluid flow within a vertical microchannel of finite length. Two membranes on the microchannel walls, with varying amplitudes, diameters, and phase lags, generate pressure that moves fluid in both directions through contraction and expansion cycles. The model is based on the conservation of mass and momentum, using a low Reynolds number approximation to capture microscale transport phenomena at biomedical scales. Dimensionless conservation equations are analytically solved under no-slip boundary conditions, with results computed in MATLAB for clarity. Axial velocity results are simulated and verified using the optimal homotopy analysis method. The model explores the influence of key parameters (UHS, me, λ, Gr, β) on pressure gradient, velocity distribution, volumetric flow rates, skin friction, Nusselt number, and stream function. The findings demonstrate that pressure from membrane motion is significantly affected by thermal effects and buoyancy forces, and flow and pumping characteristics are largely determined by the fluid's rheological qualities and the geometrical features of the membrane. This study provides novel ideas for enhancing the functionality and design of smart thermal devices while also advancing microscale heat transfer technology.

Polymerized non-fullerene small molecular acceptor as a versatile electron-transport material for 24.50 % efficiency inverted perovskite solar cells with extended spectral response

Development of novel non-fullerene electron-transport materials (ETMs) with excellent optoelectronic properties, good thermal and chemical stability, and defect passivation capability is of great significance for improving the device performance of inverted perovskite solar cells (PSCs). In this work, a polymerized non-fullerene small molecular acceptor with narrow bandgap named PY-DFT is rationally designed and synthesized. The resultant materials not only exhibits great hydrophobicity, thermal and chemical stability, but also maintains the excellent electron-transport properties of Y-type small molecule. Moreover, the electron-rich units in PY-DFT finely passivates the surface defects in perovskite. Consequently, an exceptional PCE of 24.50 % has been achieved for the champion device based on PY-DFT ETM, which is the highest efficiency for inverted PSCs based on non-fullerene ETMs to date. Notably, PY-DFT provides an extra current density of 0.25 mA/cm2 in the near-infrared light response region, where the intrinsic perovskite film has no spectral response, demonstrating attractive advantages in rationally utilization of solar spectrum. The target device without encapsulation also demonstrates good long-term operational stability. This work paves a new avenue for designing photo-active non-fullerene electron-acceptor towards efficient and stable inverted PSCs.

Low-dimensional phase optimization and defect passivation of quasi-2D perovskite to enhance electroluminescence by introducing b-NA

The energy funnel effect holds significant potential for enhancing light-emitting diode (LED) performance in the Quasi-two-dimensional (Quasi-2D) perovskite, which feature a unique multi-quantum well structure. However, random phase distribution and defects within Quasi-2D films pose challenges, leading to inefficient energy transfer and nonradiative recombination, thereby limiting device performance. Here, sodium 2-naphthalene sulfonate (b-NA) is introduced into the Quasi-2D perovskite film to enhance its the optical and electrical properties. The strong interaction between the S = O group and Na+ in b-NA with the perovskite matrix leads to reduced grain size, facilitating agglomeration and densification. This modification decreases the proportion of the low-n phase, enhances thermal stability, and passivates surface defects. Therefore, compared to the control device, the maximum brightness and external quantum efficiency of Quasi-2D perovskite LEDs with the optimal concentration (8b-NA) more than double, and the operational lifetime (T50) of the unpackaged device extends from 70.1 min to 168.5 min.

Adaptive Congestion Control in IoT Networks: Leveraging One-Way Delay for Enhanced Performance

With the exploding number of IoT devices generating vast data volumes, there is a growing risk of significant performance degradation without efficient congestion management. To tackle this challenge, efficient regulation and supervision are essential for managing congestion in IoT networks. This research work introduces a One-Way-Delay (OWD)-based congestion control (CC) method that estimates data transmission delays of the communication path and adjusts network traffic accordingly. The proposed method enhances IoT device performance by continuously monitoring OWD along the transmission path to identify and mitigate congestion. Comparative analysis with existing methods demonstrates that the proposed approach more effectively utilizes network resources, reduces congestion, and improves throughput while ensuring fairness and reliability within the IoT infrastructure. The experimental simulations show that the proposed OWD-based method outperforms well-established TCP variants such as BBR, TCP Cubic, HTCP, and New Reno, achieving average throughput improvements ranging from 4.1% to 22.7%. The proposed method also maintains fairness in mixed-traffic environments and effectively manages congestion in complex network topologies.

Enhanced optical and electrical properties of PEO/PMMA/TiO2 nanocomposites for optoelectronic applications

In this study, we synthesized titanium oxide (TiO2) nanoparticles (NPs) via the sol-gel process and incorporated them into a polymer blend of polyethylene oxide (PEO) and polymethyl methacrylate (PMMA) to form PEO/PMMA/TiO2 nanocomposites. The TiO2 NPs were integrated into the polymer matrix using the casting method at varying concentrations (1, 2, and 3 wt.%). The structural, morphological, optical, and electrical properties of the prepared TiO2 and nanocomposite films were thoroughly characterized using techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, and electrical impedance spectroscopy (EIS). TEM analysis revealed predominantly spherical TiO2 NPs with an average particle size of 15 nm. XRD and FTIR analyses confirmed the successful incorporation of TiO2 NPs and their interaction with the polymer chains, leading to modifications in the crystalline structure and chemical bonding of the nanocomposites. UV-Vis spectroscopy demonstrated a redshift in the absorption edge and increased absorbance with higher TiO₂ content, indicating enhanced optical properties. The indirect optical bandgap was observed to decrease from 4.19 eV to 2.21 eV as the TiO2 concentration increased, enhancing the material's photoresponsiveness. Additionally, the refractive index increased from 2.11 to 2.91, further supporting the potential for optical applications. EIS results showed a decrease in bulk resistance with increasing TiO2 concentration, suggesting improved electrical conductivity. These findings highlight the potential of PEO/PMMA/TiO2 nanocomposites for optoelectronic applications, where enhanced optical properties, such as improved light absorption, higher refractive index, and improved charge transport, are critical for device performance. The study offers an understanding of the PEO/PMMA/TiO2 nanocomposites, laying a foundation for future research in their applications in optoelectronic devices.

Understanding the Uncertainty in the Technical Performance Level Assessment for Wave Energy

The design of wave energy converters (WECs) has been explored with interest, with varying design concepts emerging across both research and industry. One critical element that governs the speed of adoption is the performance of a WEC concept. WEC performance has been assessed using the Technology Performance Level (TPL) assessment, which provides designers with a quantitative score, situating a grid-scale WEC concept on a scale from 1-9. The TPL assessment is designed to be used during design iteration, when a WEC concept is fully ideated, to enable designers to consider potential means of improving the downstream performance of the concept. One concern that may be slowing developers’ adoption of TPL is the inherent uncertainty in the assessment, and how uncertainty in the individual questions may contribute to the final score. In this work, we quantify the uncertainty present in the assessment using both traditional mathematical operations and a Monte Carlo simulation. Results show areas of improvement of the TPL assessment, enabling TPL practitioners and users to understand with more accuracy those design elements that can be improved to impact device performance.

A comparative numerical simulation study of CIGS solar cells with distinct back surface field layers for enhanced performance

The objective of this study is to explore the impact of various back surface field (BSF) layers including copper aluminium oxide (CuAlO2), Copper Antimony Sulphide (CuSbS2), Formamidinium tin triiodide (FASnI3), poly(3-hexylthiophene) P3HT to boost the output of conventional baseline CIGS solar cells structured. The device performance increases because of the minimized surface recombination velocity through heavily doped BSF layers, which increases the electric field at the rear contact. Among all proposed BSF layers CuAlO2 gives the best photoconversion efficiency (η) of 24.61% followed by fill factor (FF) of 83.11 %, short circuit current density (JSC) of 35.87 mA/cm2, and open circuit voltage (VOC) of 0.82 V with quantum efficiency (QE) of ∼92 % for the whole visible range with the onset happening at ∼ 560 nm, thanks to the enhancement of carrier collection when BSF layer is incorporated. The novelty in this work is that for the first time with the CuAlO2 BSF layer, 24.61% efficiency is reported at 1 μm CIGS layer thickness. We also examined how different BSFs affect the PV performance of the devices. The effect of temperature, the doping concentration of the BSFs, varying gallium proportion, JV & QE analysis, band diagram, and radiative recombination coefficient are varied to observe their impact on the PV parameters. This research introduces novel CIGS/CdS heterojunction configurations using various BSF layers to enhance efficiency, supporting the advancement of ultrathin, flexible, and tandem solar cell applications.

On-chip warped three-dimensional InGaN/GaN quantum well diode with transceiver coexistence characters

Featured with light emission and detection coexistence phenomenon, nitride-based multiple-quantum-well (MQW) diodes integrated chip has been proven to be an attractive structure for application prospects in various fields such as lighting, sensing, optical communication, and other fields. However, most of the recent reports are based on planar structures. Three-dimensional (3D) structures offer extra advantages in direction and polarization and absorption modulation and may start a new way to make the same thing over and over with interesting properties. In this paper, we designed and fabricated a single-cantilever InGaN/GaN MQW diode with warped 3D microstructure via standard microfabrication technology. Experimental results indicate that the strain architecture of the multi-layer materials is the key principle for the self-warped device. The planar structure will bear greater compressive stress while the warped beam part has less stress, resulting in differences in the optical and electrical performance. The strain-induced band bending highly influences the emission and detection properties, while the warped structure will introduce direction selectivity to the 3D device. As an emitter, 3D structures have a directional emission with lower turn-on voltage, higher capacitance, increased luminous intensity, higher external quantum efficiency (EQE), high -3dB bandwidth, and redshifted peak wavelength. Besides, it can serve as an emitter for directional-related optical communication. As a receiver, 3D structures have lower dark-current, higher photocurrent, and red-shifted response spectrum and also show directional dependence. These findings not only deepen the understanding of the working principle of the single-cantilever GaN devices but also provide important references for device performance optimization and new applications in visible light communication (VLC) technology.

Distinguishing Inner and Outer-Sphere Hot Electron Transfer in Au/p-GaN Photocathodes.

Exploring nonequilibrium hot carriers from plasmonic metal nanostructures is a dynamic field in optoelectronics, with applications including photochemical reactions for solar fuel generation. The hot carrier injection mechanism and the reaction rate are highly impacted by the metal/molecule interaction. However, determining the primary type of reaction and thus the injection mechanism of hot carriers has remained elusive. In this work, we reveal an electron injection mechanism deviating from a purely outer-sphere process for the reduction of ferricyanide redox molecule in a gold/p-type gallium nitride (Au/p-GaN) photocathode system. Combining our experimental approach with ab initio simulations, we discovered that an efficient inner-sphere transfer of low-energy electrons leads to an enhancement in the photocathode device performance in the interband regime. These findings provide important mechanistic insights, showing our methodology as a powerful tool for analyzing and engineering hot-carrier-driven processes in plasmonic photocatalytic systems and optoelectronic devices.

Self-driven Te0.65Se0.35/GaAs SWIR photodiode with spectral response to 1.55 μm for broadband imaging and optical communication

Te-based photodetectors with the merits of low cost and CMOS-compatible fabrication process have been considered promising for broadband imaging applications. Nevertheless, the spectral response of reported devices under self-powered mode is generally limited to near-infrared wavelength below 1100 nm (corresponding to the bandgap of Si). This could be ascribed to the high room-temperature carrier density in Te and the ease of forming Type-I heterojunctions between Te and other semiconductors, which impede the effective generation and separation of photocarriers. This study reports the bandgap engineering of Te through Te-Se alloying and the fabrication of Te0.65Se0.35/Al2O3/GaAs photodiode with an extended response spectrum through ultraviolet to the short-wave infrared (SWIR) band of 1550 nm at zero bias. The effects of interface passivation on the photosensing properties were also investigated. The optimized heterojunction exhibits a pronounced photovoltaic response to 1342 nm (1550 nm) infrared light with an open-circuit voltage of ∼0.12 V (0.07 V). Particularly, the dark current density reaches a record low level of 0.1 nA/cm2 at 0 V bias, leading to a high on-off current ratio of 4.5×104 and detectivity of 1.1×107 Jones at room temperature for 1342 nm light. Self-powered UV-Vis-SWIR broadband imaging and optical communication are realized by leveraging the favorable device performance. Our work provides a frame of reference for exploring more Te1-xSex-based photodetectors. Meanwhile, it may be combined with well-developed semiconductor processing technologies for optoelectronics integration.

Advances in defect characterization techniques using polarized light observation in SiC wafers for power devices

This short review provides an overview of advancements in the characterization of defects in silicon carbide (SiC) wafers using polarized light observation. SiC, which has a wide bandgap and excellent thermal and electrical properties, is widely used in power devices. However, various defects such as threading screw dislocations (TSD), threading edge dislocations (TED), and basal plane dislocations (BPD) can significantly affect device performance and reliability. Polarized light observation offers a nondestructive method for visualizing these defects and analyzing the stress fields induced within the SiC crystal structure. This paper summarizes recent developments in this technique, including the application of analyzer rotation to enhance the contrast in defect visualization. Furthermore, the development of automated systems for rapid wafer evaluation is discussed, highlighting the role of polarized light observation in improving quality control and production efficiency in SiC power device manufacturing.