Compensation Layer Research Articles

Real-time Error Compensation Transfer Learning with Echo State Networks for Enhanced Wind Power Prediction

Accurate wind power forecasting is essential for efficient energy management and grid stability, enabling energy providers to balance supply and demand, optimize renewable energy integration, reduce operational costs, and enhance power grid reliability. The Echo State Network (ESN) is widely used for modeling nonlinear dynamic systems due to its simple and rapid training process. However, ESNs can be prone to system errors, leading to inaccurate models when handling high-order nonlinear complexities. To overcome this, we developed the Error Compensation Transfer Learning Echo State Network (ETL-ESN), which combines a computing layer based on ESN and a compensation layer using transfer learning. Our model identifies error auto-correlation as a key factor that increases variance in ESN predictions, and addresses this with an error compensation layer to reduce system errors. We further leverage transfer learning to prevent overfitting within the error domain. Extensive experiments using real-world wind power data demonstrate that the ETL-ESN model reduces training time from 65 s to 2 s compared to LSTM, while lowering MAE by up to 95%. The ETL-ESN achieves a 95% to 98% improvement in prediction accuracy across different turbines compared to traditional models. The code and datasets used in this study are available at GitHub repository https://github.com/zhuyingqin/Error-Transfer-ESN for further research and replication.

Warpage analysis of multilayer thin film/substrate systems using the Eigenstrain method

Warpage resulting from the deposition of films on substrates remains a persistent challenge that significantly impacts the application of numerous advanced devices. To precisely evaluate warpage in multilayer thin film/substrate systems, we employ the eigenstrain method in the warpage analysis. An analytical model is developed to predict warpage and residual stress in multilayer film/substrate system based on classical laminate theory. We introduce a novel concept termed “Eigenstress”, which serves as the fundamental cause of warpage and characterizes the influence of the manufacturing process on warpage. Theoretical analysis and simulation demonstrate that warpage is entirely determined by eigenstress and other process-independent parameters. This model also explains that there is little interaction between thin films deposited on the same substrate. An experimental method is studied for measuring eigenstress using a standard plate. The measured eigenstress differs significantly from the corresponding thermal stress. We also propose a critical condition and its governing equation for warpage in multilayer film/substrate systems. Experimental results confirm that adding a compensation layer on a warped substrate can considerably reduce warpage. The warpage model based on “Eigenstress” provides a theoretical foundation for accurately predicting and controlling warpage in multilayer thin film/substrate systems.

Design and implementation of a temperature-insensitive heterogeneous resonant magnetic field sensor

A heterogeneous resonant magnetic field sensor is developed by using a FeGa plate, a quartz crystal double-ended tuning fork (DETF) resonator and a sapphire crystal plate. The double ends of the DETF are bonded to the ends of the magnetostrictive FeGa thin plate through two spacers, forming a resonant magnetic sensitive element. The C-cut sapphire crystal plate as a temperature compensation layer is bonded to the bottom of the magnetic sensitive element. When the temperature fluctuates, the bending deformation caused by the heterogeneous sensitive structure eliminates the thermal stress caused by the thermal expansion effect, thereby reducing the temperature drift of the sensor. The impact of different thicknesses of the sapphire substrate on reducing temperature drift in the sensor is analysed through theoretical calculation and finite element simulation. A sensor prototype was fabricated with a sapphire substrate thickness of 0.45 mm. The experimental results demonstrate that the temperature coefficient of frequency (TCF) of the sensor is reduced from 8.73 Hz/°C to 0.47 Hz/°C in the 0 °C to 60 °C range, and the sensitivity and resolution in the linear region of the sensor are 5.63 Hz/Oe and 42μOe (4.2nT), respectively.

Research on multi-probe energy response compensation for X/γ dose rate meter

Dose rate meters operating in pulse counting mode usually encounter the problem of uneven energy response. While current methods of coating a single probe with a metal layer can effectively improve the flatness of the energy response, the energy range of the flat response is limited. In this research, a multi-probe energy response compensation method was proposed to solve the problem of uneven energy response of a CsI(Tl) dose rate meter. In this method, different relative energy response curves were obtained by adding different hardware compensations to a probe. Then, two to four relative energy response curves were selected and weighted to obtain a flatter response within the energy region of interest. Specifically, first, 51 compensation schemes were obtained by changing the geometry and material parameters of the CsI(Tl) probe compensation layer. Second, the relative energy response curves of CsI(Tl) probes with 51 compensation schemes were obtained by MCNP simulation. Finally, the weight coefficient of each relative energy response curve was determined by overdetermined equations, and the combination with the smallest relative energy response deviation was selected. Within the energy range of 80–1500 keV, the optimal two-probe compensation scheme was selected from one to three probe compensation schemes. After the dual probe combination compensation, the relative energy response deviation ranged from -23.0% to 5.0%. Within the energy range of 50–3000 keV, the compensation schemes of one to four probes were traversed. The optimal three-probe compensation schemes were selected. After combined compensation, the relative energy response deviation ranged from -27.3% to 15.3%. Furthermore, the compensation effect of multiple probes was better than that of single probes in both energy regions of interest. Simulation results demonstrated that our proposed method can significantly improve the flatness of the energy response of dose rate meters based on CsI(Tl).

Performance Enhancement of InGaN Laser Photovoltaic Cell With AlGaN Strain Compensation Layer Irradiated by 450 nm Laser

Performance Enhancement of InGaN Laser Photovoltaic Cell With AlGaN Strain Compensation Layer Irradiated by 450 nm Laser

An Angle-Stable Ultra-Wideband Single-Layer Frequency Selective Surface Absorber

An ultra-wideband polarization-insensitive frequency selective surface (FSS) absorber is proposed for S to K-band applications. The absorber comprises two compensation slabs, a lossy FSS layer and a grounded dielectric plate. The FSS unit cell is a combination of a second-order Chinese knot and a cross. To enhance the bandwidth and angular stability of the single-layer FSS absorber, a compensation layer composed of FR4 and polymethyl methacrylate (PMMA) slabs is incorporated. The proposed FSS absorber demonstrates a remarkable absorption rate of over 90% within the frequency range of 3.1–22.1 GHz, exhibiting a fractional bandwidth of 150.8%. Even when subjected to an oblique incidence of 45°, the absorber maintains an 80% absorption rate in the frequency range of 4.4–19.1 GHz for both TE and TM polarizations. The total thickness of the FSS absorber is 0.0848 λL (the wavelength at the lowest cutoff frequency), and only 1.08 times the Rozanov limit. To validate the design, a prototype of the proposed absorber was fabricated and measured. Good agreements were observed between the simulations and measurements.

Flatness Enhancement of Metal-Supported Solid Oxide Fuel Cells with Additional Compensation Layer

Solid oxide fuel cells are high-temperature fuel cells which offer several advantages: high efficiency, fuel flexibility, high-quality waste heat, and the use of non-noble metal catalysts. Metal-supported solid oxide fuel cells, in which the ceramic mechanical support layer is replaced with the metal support, are considered as next-generation solid oxide fuel cells because of their enhanced mechanical/thermal ruggedness compared to conventional ceramic-supported solid oxide fuel cells. However, different thermomechanical behavior of metal support and ceramic layers during sintering makes metal-supported cells vulnerable to warping. Cell warpage must be minimized because it reduces not only uniformity of wet-chemical coating, but also actual contact area between electrode and interconnect, increasing the contact resistance.In this study, causes of metal-supported cell warpage are identified, and the design that can minimize cell warpage is suggested for successful scale-up of metal-supported solid oxide fuel cells. Through thermomechanical and residual stress analyses, it is found that residual stress derived from coefficient of thermal expansion mismatch between electrode layers and the metal substrate is the main cause of the warpage of metal-supported solid oxide fuel cells. Based on these results, a novel design that has thicker metal protection layer on the opposite side of the electrolyte is proposed for minimizing cell warpage due to residual stress. Through the design modification, vertical deformation of 2-inch metal-supported solid oxide fuel cell can be successfully controlled to 17.36% of the previous design. Furthermore, electrochemical evaluation showed a 21% decrease in ohmic ASR and a 25% increase in peak power density after the design modification, implicating reduction of contact resistance as a result of increased contact area by enhanced flatness.

Enlarging the colour gamut of LCD with YAG-LED by using a liquid crystal based polarisation interference filter

ABSTRACT We proposed a polarisation interference filter (PIF) to enlarge the colour gamut of liquid crystal display (LCD) with YAG-LED backlight, and the PIF consists of two crossed polarisers and two liquid crystal layers. The PIF can be used in the backlight unit to improve the colour gamut of LCD by eliminating unwanted colours in the spectrum. When the PIF is integrated into the YAG-LED backlight, the colour gamut of the LCD can be improved from 84% NTSC to 116% NTSC, and the colour gamut is larger than 116% NTSC within 30° polar angle. When a compensation layer is employed, the colour gamut distribution of LCD is more uniform at full viewing angles. The PIF has great potential for achieving a wide colour gamut display.

Thermal Lensing Effect Reduction on High-Power Multi-Mode Diode Lasers

High-power broad-area diode lasers are needed for a variety of applications. However, such lasers suffer from deteriorated beam quality due to multimode behavior in the lateral direction at high power. We propose an approach to reduce the thermal lensing effect by introducing a thermal compensation layer. As a result of reducing the thermal lensing effect, we demonstrated that the lateral divergence angle was reduced by 16.2%, the lateral beam parameter product was reduced by 12.8%, and the lateral brightness was increased by 18.4% for 230 μm wide diode operating at 50 A current while maintaining a good output power.

Effect of the AlN strain compensation layer on InGaN quantum well red-light-emitting diodes beyond epitaxy.

An atomically thick AlN layer is typically used as the strain compensation layer (SCL) for InGaN-based-red light-emitting diodes (LEDs). However, its impacts beyond strain control have not been reported, despite its drastically different electronic properties. In this Letter, we describe the fabrication and characterization of InGaN-based red LEDs with a wavelength of 628 nm. A 1-nm AlN layer was inserted between the InGaN quantum well (QW) and the GaN quantum barrier (QB) as the SCL. The output power of the fabricated red LED is greater than 1 mW at 100 mA current, and its peak on-wafer wall plug efficiency (WPE) is approximately 0.3%. Based on the fabricated device, we then used numerical simulation to systematically study the effect of the AlN SCL on the LED emission wavelength and operating voltage. The results show that the AlN SCL enhances the quantum confinement and modulates the polarization charges, modifying the device band bending and the subband energy level in the InGaN QW. Thus, the insertion of the SCL considerably affects the emission wavelength, and the effect on the emission wavelength varies with the SCL thickness and the Ga content introduced into the SCL. In addition, the AlN SCL in this work reduces the LED operating voltage by modulating the polarization electric field and energy band, facilitating carrier transport. This implies that heterojunction polarization and band engineering is an approach that can be extended to optimize the LED operating voltage. We believe our study better identifies the role of the AlN SCL in InGaN-based red LEDs, promoting their development and commercialization.

Optimization for energy response characteristics of plastic scintillators based on genetic algorithm

To address the problem that the energy response of the plastic scintillator detector is very low in the low energy range, this paper proposes a method to optimize the energy response characteristics by combining the CaWO4 energy compensation layer and the genetic algorithm. First, the energy deposition of X/γ rays in a plastic scintillator with a CaWO4 energy compensation layer is modeled and simulated using MCNP software; then, the thickness and hollow radius of the compensation layer are optimized by using genetic algorithm to run this simulation program. The results show that after adding a CaWO4 compensation layer with a thickness of 45 µm and a hollow radius of 1 cm at the front of the plastic scintillator, its energy response characteristics are consistent in the range of 50 keV to 1.5 MeV, which meets the requirement of IEC 61584:2001 for the energy response coefficient less than ±30%. The maximum deviation of the energy response coefficient at the energy point of 0.662 MeV is reduced from 44% to 13%.

Strain‐Stabilized CsPbI3 Perovskite via Organopolysilazane for Efficient Solar Cells with Efficiency over 19%

AbstractPrincipally, all‐inorganic perovskite crystals, such as CsPbI3, possess higher thermal stability than their organic–inorganic hybrid counterparts, like CH3NH3PbI3, due to the type of chemical bond variants. However, considering a retained strain in these stiff films, it is a challenge to stabilize CsPbI3 within the photoactive phase for photovoltaic application under ambient conditions. This article reports organopolysilazane (OPSZ) as a strain compensation layer that regulates the tense strain during the annealing process, a very attractive feature for all‐inorganic perovskite solar cells with a CsPbI3 active layer. When depositing OPSZ onto the surface of CsPbI3 film for thin‐film solar cell devices with FTO/c‐TiO2/CsPbI3/spiro‐OMeTAD/Au architecture, an efficiency of 19.12% is achieved under standard illumination test conditions. This strain compensation layer offers a viable pathway to develop efficient and stable solar cells with inorganic perovskite crystalline thin films for scale‐up and practical applications.

Nanoporous GaN on p-type GaN: a Mg out-diffusion compensation layer for heavily Mg-doped p-type GaN

Embedding p-type gallium nitride (p-GaN) with controlled Mg out-diffusion in adjacent epitaxial layers is a key for designing various multi-junction structures with high precision and enabling more reliable bandgap engineering of III-nitride-based optoelectronics and electronics. Here, we report, for the first time, experimental evidence of how nanoporous GaN (NP GaN) can be introduced as a compensation layer for the Mg out-diffusion from p-GaN. NP GaN on p-GaN provides an ex-situ formed interface with oxygen and carbon impurities, compensating for Mg out-diffusion from p-GaN. To corroborate our findings, we used two-dimensional electron gas (2DEG) formed at the interface of AlGaN/GaN as the indicator to study the impact of the Mg out-diffusion from underlying layers. Electron concentration evaluated from the capacitance-voltage measurement shows that 9 × 1012 cm−2 of carriers accumulate in the AlGaN/GaN 2DEG structure grown on NP GaN, which is the almost same number of carriers as that grown with no p-GaN. In contrast, 2DEG on p-GaN without NP GaN presents 9 × 109 cm−2 of the electron concentration, implying the 2DEG structure is depleted by Mg out-diffusion. The results address the efficacy of NP GaN and its’ role in successfully embedding p-GaN in multi-junction structures for various state-of-the-art III-nitride-based devices.

A deep trench super-junction LDMOS with double charge compensation layer

A deep trench super-junction LDMOS with double charge compensation layer (DC DT SJ LDMOS) is proposed in this paper. Due to the capacitance effect of the deep trench which is known as silicon–insulator–silicon (SIS) capacitance, the charge balance in the super-junction region of the conventional deep trench SJ LDMOS (Con. DT SJ LDMOS) device will be broken, resulting in breakdown voltage (BV) of the device drops. DC DT SJ LDMOS solves the SIS capacitance effect by adding a vertical variable doped charge compensation layer and a triangular charge compensation layer inside the Con. DT SJ LDMOS device. Therefore, the drift region reaches an ideal charge balance state again. The electric field is optimized by double charge compensation and gate field plate so that the breakdown voltage of the proposed device is improved sharply, meanwhile the enlarged on-current region reduces its specific on-resistance. The simulation results show that compared with the Con. DT SJ LDMOS, the BV of the DC DT SJ LDMOS has been increased from 549.5 to 705.5 V, and the R on,sp decreased to 23.7 mΩ·cm2.

Compensation layer‐added federated learning receiver: Design and implementation

The federated learning‐based symbol detection technique has attracted much attention recently due to its application of processing data at the network edge (ie, mobile user equipment) in a distributed manner. In this regard, the federated receiver is presently being promoted as a replacement for and improvement on the conventional model‐based receiver. This paper proposes an average pooling with compensation layer and an average pooling with dense layers‐added federated receiver for symbol detection in a downlink fading channel. In average pooling with a compensation scheme, the average of the input data is extracted and then ripples of the data are minimized by multiplying the weight coefficient in the compensation layer. In average pooling with dense scheme, two pooling schemes, such as average pooling and max‐pooling, are incorporated into dense layers with various activation functions. Simulation results are provided to demonstrate that the proposed compensation layer‐added federated receiver outperforms the conventional federated receiver.

An angularly stable and optically transparent broadband conformal microwave absorber using “diamond-shaped” pattern

The emergence of metamaterials provides a novel solution to realize high-performance optically transparent electromagnetic (EM) absorber. In this paper, an optically transparent metamaterial-based microwave absorber, which features wide operating bandwidth and angular stability, is presented both numerically and experimentally. The proposed structure is mainly composed of a transparent indium-tin-oxide (ITO) “diamond-shaped” pattern layer and a polyethylene terephthalate (PET) substrate layer. By employing the polyvinyl chloride (PVC) compensation layer with appropriate thickness, we improve the broadband impedance matching with free space. Since we use flexible conductors and dielectrics, the absorber is able to adhere closely to the object. According to the spectrometer measurements, the proposed absorber achieves an averagely high transmittance of 70.2% in the visible band. The fitness of numerical simulations and microwave measurements demonstrate that the absorption exceeds 90% in an ultra-broadband operating frequency from 8.02 to 33.91 GHz (corresponding to 123.5% fractional bandwidth) is achieved. Besides, it also demonstrates excellent absorption performance for wide-angle oblique incidence waves approaching 45°. Finally, the absorber with conformal configuration which can effectively suppresses the backscattering of the arched metal surface in the considered broadband frequency range from 8 to 32.05 GHz is also realized. The proposed wide-angle and optically transparent broadband absorber can be utilized in specific engineering scenarios, such as aircraft cockpit and solar panel.

4H–SiC floating junction Schottky barrier diode with compensation layer of engineered cathode structure: Cone-shaped electric field, current density waveform, and applications

In order to further elevate its adaptability as a power device, the electrical properties of 4H–SiC floating-junction Schottky barrier diode with the compensation layer (CL) of engineered cathode structure were studied in this paper. The n-type CL was introduced near the cathode side of the device drift region, which can effectively compensate the transient recovery process, and alleviate the bipolar degradation of the unipolar device (RSF: 3.3589; trr: 1.0437 ns). The generation and transport mechanism of the current density suitable for static and dynamic performance was analyzed under the micron-meter-level condition. Some influencing factors, including the internal structure dimensions, the doping of CL, and temperature, were discussed quantitatively. The electric field distribution in the device was obtained according to Maxwell's theory (ET: 3.50 × 106 V/cm). By embedding some p−-type layers in the upper part of drift region, the discharge output of p+-type-floating layer can be availably inhibited (Qrr: 7.0260 × 10–15 C/μm).

One-Pot Preparation of Lithium Compensation Layer, Lithiophilic Layer, and Artificial Solid Electrolyte Interphase for Lean-Lithium Metal Anode.

Lithium metal is an ideal anode for high-energy-density batteries. However, the low Coulomb efficiency and the generation of dendrites pose a significant limitation to its practical application, while the excess lithium in the battery also generates serious safety concerns. Herein, a layer-by-layer optimized multilayer structure integrating an artificial solid electrolyte interphase (LiF) layer, a lithiophilic (LixAu alloy) layer, and a lithium compensation layer is reported for a lean-lithium metal battery, where each layer acts synergistically to stabilize the lithium deposition behaviors and enhances the cycling performance of the battery. The optimized anode could effectively induce homogeneous reversible lithium deposition under the synergistic effect of multilayer films and keep the integrity of the morphological structure unbroken during the deposition. The presence of the lithium compensation layer allows the half-cell to have a high initial CE of 158.9%, and the action of the LiF layer and lithiophilic layer maintains an average CE of 98.8% over 160 cycles, which further demonstrates the stability of the structure. As a result, when combined with LiFePO4 cathode, an initial capacity of 148 mAh g-1 and a retention rate of 97.5% over 130 cycles were achieved.

Quantitative Investigation Nonequilibrium Inhomogeneous Plasma of the Heliosphere With Runaway Electrons

We prove that a nonequilibrium inhomogeneous giant gas discharge is realized in the heliosphere with huge values of the parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$E/N$ </tex-math></inline-formula> , which determines the temperature of electrons. This quasi-stationary discharge determines the main parameters of the weak solar wind (SW) in the heliosphere. In connection with the development of space technologies and the human spacewalk, the problem of the nature of the SW is acute. The study of the interference of gravitational and electrical potentials at the earth’s surface began with the work of William Gilbert 1600. Such polarization effects–the interference of Coulomb and gravitational forces–have not been studied well enough even in the heliosphere. Our article is devoted to this problem. The Pannekoek–Rosselan–Eddington model does not consider the important role of highly energetic running (away from the Sun) electrons and, accordingly, the duality of electron fluxes in the heliosphere (from the Sun and to the Sun) According to an alternative model formulated by us, highly energetic (escaping from the positively charged Sun) electrons leave the Sun and the heliosphere, and weakly energetic ones, unable to leave the Coulomb potential well (hole–the positively charged Sun and the heliosphere–return to the positively charged Sun. The weak difference between the opposite currents of highly energetic (escaping from the Sun) electrons and weakly energetic (returning to the Sun) electrons is compensated by the current of positive ions and protons from the Su–SW. These dynamic processes maintain a quasi-constant effective dynamic charge of the Sun and the entire heliosphere all the way to the earth’s orbit. At the same time, quasi-neutrality (see discussion in the following) in the Sun and heliosphere is well performed up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−36</sup> . According to experiments and analytical calculations based on our model: 1) the plasma in the corona is nonequilibrium; 2) the maximum electron temperature is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T_{e}$ </tex-math></inline-formula> 1–2 million degree; 3) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T_{e}$ </tex-math></inline-formula> grows from 1000 km away from the Sun (see discussion in the following); and 4) the role of highly energetic electrons escaping from the plasma leads to a significant increase in the effective: solar charge and electric fields in the heliosphere in relation to the Pannekoek–Rosselan–Eddington model. This is due to the absence of a compensation layer that screens the effective charge of the Sun It is not formed due to the escape of highly energetic electrons (as in a conventional gas discharge) from the entire heliosphere with high temperatures exceeding the temperature of the Sun’s surface. Thus, the process of escape of highly energetic electrons forms the internal EMF of the entire heliosphere. Interference of gravitational and Coulomb potentials in the entire heliosphere is considered, and it is being manifested in generation of two opposite flows of particles: 1) that are neutral or with a small charge (to the Sun) and 2) in the form of high-energy electrons (escaping from the positively charged Sun) and an SW with positively charged ions with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z/M</i> <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\ge0.107$ </tex-math></inline-formula> (from the positively charged Sun). The calculated values of the registered ion parameters in the SW were compared with experimental observations. Reasons for generating the ring current in inhomogeneous heliosphere and inapplicability of the Debye theory in describing processes in the SW (plasma with current) are considered.

Highly Reliable Flexible Device with a Charge Compensation Layer.

Flexible devices fabricated with a polyimide (PI) substrate are essential for foldable, rollable, and stretchable products and various applications. However, inherent technical challenges remain in mobile charge-induced device instabilities and image retention, significantly hindering future technologies. Here, we introduce a new barrier material, SiCOH, into the backplane of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) and applied it to production-level flexible panels. We found that the SiCOH layer effectively compensates for the surface charging induced by fluorine ions at the interface between the PI substrate and the barrier layer under bias stress, thereby preventing abnormal positive shifts in threshold voltage (Vth) and image disturbance. The a-IGZO TFTs and metal-insulator-metal and metal-insulator-semiconductor capacitors with a SiCOH layer demonstrate reliable device performance, Vth shifts, and capacitance changes with an increase in gate bias stress. A flexible device with SiCOH enables the suppression of abnormal Vth shifts associated with PIs and plays a vital role in image sticking. This work provides new insights into process integrity and paves the way for expediting versatile form factors.