FOM Value Research Articles

A triple plasmon-induced transparency terahertz sensor based on graphene metamaterials

A metamaterial-based terahertz sensor design is presented in this paper. The metamaterial unit structure comprises a graphene cross and three sets of graphene strips, which collectively achieve a triple plasmon-induced transparency (PIT) in both polarization directions. The theoretical results based on the Lorentz resonance theoretical model are in good agreement with finite difference time domain (FDTD) simulations. The sensor is polarization-independent and changes in the angle of incidence between 0° and 10° have a negligible impact on the sensing performance. Furthermore, the sensor exhibits a notable slow-light effect, with a maximum sensitivity of 1.65 THz/RIU and a FOM value of 4.74/RIU for the triple PIT, which is superior to that of comparable devices.

A 99.99% current efficiency fast transient response capacitor-less LDO with feedforward compensation technique based on small-signal gain stage

An ultra-low power capacitor-less LDO with feedforward compensation technique based on the small-signal gain stage and composite transient enhancement structure is proposed. The feedforward compensation technique based on the small-signal gain stage reaches a low frequency zero ,by utilizing the compensating effect of the zero to relieve the adverse effects of the pole, thereby enhancing the stability and performance of the circuit. Furthermore, the small gain stage can adjust the quiescent current consumption,contributing to a significant reduction in system energy consumption. The proposed composite transient enhancement structure can reduce the transition time of the circuit, adjust the gain of the circuit under different operating conditions to achieve precise gain control and improve the transient performance of the system. The proposed LDO is designed using SMIC 0.18um CMOS process. The simulation results show the total quiescent current is 0.94uA and the current efficiency is up to 99.99%. The extremely low FoM value of 0.04 represents a good transient performance. Synthesizing the comparison of various parameters, the superiority of this design can be clearly concluded.

Directly patterned ITO nanoparticle-based transparent electrode using co-solvent-based aerosol jet printing for transparent thin film heaters

High-performance transparent thin film heaters (TFHs) employing cost-effective nanoparticle-based transparent electrodes have attracted significant attention for applications in multifunctional smart windows. This study demonstrates the fabrication of high-performance TFHs featuring directly patterned Sn-doped In2O3 (ITO) nanoparticle electrodes using a methanol and ethylene glycol co-solvent-based aerosol jet printing (AJP) process. Our method utilizes a co-solvent ITO nanoparticle solution, blending methanol and ethylene glycol, to improve the surface uniformity and roughness of the AJP-processed ITO nanoparticle electrodes. The optimization of these electrodes was assessed using the figure of merit (FoM=T10/Rsh) value, derived from the transparency and sheet resistance of the electrodes. As a result of the AJP process and post-annealing optimization, the directly patterned ITO nanoparticle electrodes exhibited a high FoM value of 16.1 Ω−1, attributed to a high optical transmittance of 90.6 % and low sheet resistance of 23.20 Ω/sq. These optimized ITO nanoparticle electrodes were subsequently applied to TFHs through precise patterning of ITO electrodes via AJP. The ITO nanoparticle-based TFHs, benefiting from superior conductivity and precise AJP patterning, demonstrated a saturation temperature of 118.2 °C when subjected to a voltage of 9 V. Thermal stability and uniformity tests showed a temperature deviation of less than 5 %, validating the reliability of the TFHs. The performance of the AJP-processed ITO nanoparticle-based TFHs highlights the feasibility of cost-effective transparent TFHs for multifunctional smart windows, showing potential applications in electric vehicles and next-generation smart buildings.

Multi-Scenario Simulation of Land Use Change and Ecosystem Service Value Based on the Markov–FLUS Model in Ezhou City, China

Changes in land use patterns, types, and intensities significantly impact ecosystem services. This study follows the time series logic from history to the expected future to investigate the spatial and temporal characteristics of land use changes in Ezhou and their potential impacts on the ecosystem services value (ESV). The results show that the Markov–FLUS model has strong applicability in predicting the spatial pattern of land use, with a Kappa coefficient of 0.9433 and a FoM value of 0.1080. Between 2000 and 2020, construction land expanded continuously, while water area remained relatively stable, and other land types experienced varying degrees of contraction. Notably, the area of construction land expanded significantly compared to 2000, and it expanded by 70.99% in 2020. Moreover, the watershed area expanded by 9.30% from 2000 to 2010, but there was very little change in the following 10 years. Under the three scenarios, significant differences in land use changes were observed in Ezhou City, driven by human activities, particularly the strong expansion of construction land. In the inertial development scenario, construction land expanded to 313.39 km2 by 2030, representing a 38.30% increase from 2020. Conversely, under the farmland protection scenario, construction land increased to 237.66 km2, a 4.89% rise from 2020. However, in the ecological priority development scenario, the construction land area expanded to 253.59 km2, a 10.13% increase from 2020. Compared to 2020, the ESV losses in the inertia development and farmland protection scenarios were USD 4497.71 and USD 1072.23, respectively, by 2030. Conversely, the ESV under the ecological protection scenario increased by USD 2749.09, emphasizing the importance of prioritizing ecological protection in Ezhou City’s development. This study may provide new clues for the formulation of regional strategies for sustainable land use and ecosystem restoration.

A semi-cellular Z-type Gate SOI-LDMOS with Improved Gate Control Capability

A Semi-cellular Z-type Gate SOI-LDMOS (ZG LDMOS) with Improved Gate Control Capability is proposed, and its physical mechanism is studied by SENTAURUS. It is a semi-cellular structure similar to "Z" consisting of a Trench Gate (TG) and a Planar Gate (PG). At the on-state, the inversion layer of the conductive channel is not only formed at the top of the P-well region, but also formed along the side wall of the Z Gate, expanding the width of the channel, improving the electron injection ability and reducing the specific on-resistance (Ron,sp). In addition, the Z Gate can also form a uniform current distribution from the drift region to the bottom, which is helpful to reduce the Ron,sp, improve the transconductance and enhance the current control ability. The 3D simulation results show that BV, Ron,sp are 187.3 V and 4.45 mΩ cm2, respectively. The FOM reached 7.91 MW/cm2. Compared with the conventional LDMOS, the FOM value of ZG LDMOS increased by 58.8 %, which breaks through the silicon limit of RESURF.

Nanosecond pulsed laser etching anti-reflective gratings and synchronous laser annealing for performance optimization of Ag/AZO thin films

Nanosecond pulsed laser etching for fabricating anti-reflective gratings and inducing synchronous laser annealing was performed on Ag/AZO films. The optimum grating pitch was determined by performance analyses of laser-etched unidirectional gratings, based on which laser-etched bidirectional gratings were fabricated to further determine the optimum grating tilt angle. The results revealed that with the increase of grating pitch, the grating ridge total-side-area was gradually decreased to cause a gradually weakened anti-reflective effect, but the superimposed heat-affected zones between adjacent grooves became smaller or even disappeared, which brought about different synchronous laser annealing effects. The unidirectional grating-textured film with a medium grating pitch of 200 μm showed the best overall performance under the combined influence from anti-reflective gratings and synchronous laser annealing. For the bidirectional gratings, although increasing the grating tilt angle did not change the grating ridge total-side-area, it would enable the laser energy to be more uniformly distributed on the whole film surface, producing a better synchronous laser annealing effect. The bidirectional grating-textured film with a grating tilt angle of 90° had the best overall performance with the highest FOM value of 2.18 × 10−2 Ω−1 that was ∼3.2 times that of the as-prepared film. The results are instructive for preparing high-performance TCO-based films.

Large-Area Flexible Carbon Nanofilms with Synergistically Enhanced Transmittance and Conductivity Prepared by Reorganizing Single-Walled Carbon Nanotube Networks.

Large-area flexible transparent conductive films (TCFs) are highly desired for future electronic devices. Nanocarbon TCFs are one of the most promising candidates, but some of their properties are mutually restricted. Here, a novel carbon nanotube network reorganization (CNNR) strategy, that is, the facet-driven CNNR (FD-CNNR) technique, is presented to overcome this intractable contradiction. The FD-CNNR technique introduces an interaction between single-walled carbon nanotube (SWNT) and Cu─-O. Based on the unique FD-CNNR mechanism, large-area flexible reorganized carbon nanofilms (RNC-TCFs) are designed and fabricated with A3-size and even meter-length, including reorganized SWNT (RSWNT) films and graphene and RSWNT (G-RSWNT) hybrid films. Synergistic improvement in strength, transmittance, and conductivity of flexible RNC-TCFs is achieved. The G-RSWNT TCF shows sheet resistance as low as 69Ωsq-1 at 86% transmittance, FOM value of 35, and Young's modulus of ≈45MPa. The high strength enables RNC-TCFs to be freestanding on water and easily transferred to any target substrate without contamination. A4-size flexible smart window is fabricated, which manifests controllable dimming and fog removal. The FD-CNNR technique can be extended to large-area or even large-scale fabrication of TCFs and can provide new insights into the design of TCFs and other functional films.

Simulating Urban Expansion from the Perspective of Spatial Anisotropy and Expansion Neighborhood

Exploring spatial anisotropy features and capturing spatial interactions during urban change simulation is of great significance to enhance the effectiveness of dynamic urban modeling and improve simulation accuracy. Addressing the inadequacies of current cellular automaton-based urban expansion models in exploring spatial anisotropy features, overlooking spatial interaction forces, and the ineffective expansion of cells due to traditional neighborhood computation methods, this study builds upon the machine learning-based urban expansion model. It introduces a spatial anisotropy index into the comprehensive probability module and incorporates a gravity-guided expansion neighborhood operator into the iterative module. Consequently, the RF-CNN-SAI-CA model is developed. Focusing on the 21 districts of the main urban area in Chongqing, the study conducts comparative analysis and ablation experiments using different models to simulate the land use changes between 2010 and 2020. Different model comparison results show that the recommended model in this study has a Kappa value of 0.8561 and an FOM value of 0.4596. Compared with the RF-CA model and the FA-MLP-CA model, the Kappa values are higher by 0.0407 and 0.1577, respectively, while the FOM values are improved by 0.0529 and 0.0654, respectively. Ablation experiment results indicate that removing gravity, SAI, and expansion neighborhood operators leads to a decrease in both Kappa and FOM values. These findings demonstrate that the RF-CNN-SAI-CA model, based on the expanded neighborhood iteration algorithm, effectively integrates spatial anisotropy features, captures spatial interaction forces, and resolves neighborhood cell failure issues, thereby significantly improving simulation effectiveness.

Modeling future land use and land cover under different scenarios using patch-generating land use simulation model. A case study of Ndola district

Accurate predictions of changes in Land-use and Land-cover (LULC) are crucial in climate modeling, providing valuable insights into the possible effects of land-use alterations on Earth’s intricate system. This study focuses on forecasting and examining future LULC changes in the Ndola district from 2022 to 2042, considering three scenarios: Traditional mode (TM), Ecological protection (EP), and Economic Development (ED). TM reflects past land use changes, EP prioritizes environmental conservation, and ED emphasizes economic growth and urbanization. Using the patch-generating land use simulation (PLUS) model, we achieved precise predictions of LULC changes in Ndola district. The model, which combines LEAS rule-extraction with a CA model using CARS, addresses limitations of previous models like CLUE-S, CA-Markov, and FLUS by accurately simulating scattered LULC patterns and the mutual attraction and evolution of open space and urban land under different policies. Using LULC data from the livingatlas platform for the base period (2017–2022), the model demonstrated a Kappa coefficient of 78% and a FoM value of 0.34. Key findings indicate significant trends, such as reductions in forest and agricultural lands in the TM and ED scenarios, with rangeland expanding consistently across all scenarios, particularly in the ED scenario. The decline in agricultural and forest lands raises concerns about household food security, habitat fragmentation, biodiversity loss, and diminished ecosystem services. Urban sprawl onto other land uses could further strain urban infrastructure and public services. Future research should incorporate uncertainty analysis methods such as fuzzy logic or Bayesian methodologies to quantify and differentiate uncertainties related to modeling simulations.

Flexible Transparent Electrode Based on Ag Nanowires: Ag Nanoparticles Co-Doped System for Organic Light-Emitting Diodes.

Flexible organic light-emitting diodes (FOLEDs) have promising potential for future wearable applications because of their exceptional mechanical flexibility. Silver nanowire (Ag NW) networks are the most promising candidates to replace indium tin oxide (ITO), which is limited by its poor bendability. In this study, three different methods including methanol impregnation, argon plasma treatment, and ultraviolet radiation were used to reduce the junction resistance of Ag NWs to optimize the flexible transparent electrodes (FTEs); which were prepared using Ag NWs and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS). Then, the optoelectronic properties of the FTEs were further improved by using a co-doped system of silver nanowires and silver nanoparticles (Ag NPs), the structure of which consisted of PET/Ag NWs: Ag NPs/PEDOT: PSS/DMSO. The largest FOM value of 1.42 × 10-2 ohm-1 and a low sheet resistance value of 13.86 ohm/sq were obtained using the optimized FTEs. The prepared FOLED based on the optimized FTEs had a luminous efficiency of 6.04 cd/A and a maximum EQE of 1.92%, and exhibited no observed decline in efficiency when reaching maximum luminance. After 500 bending tests, the luminance still reached 82% of the original value. It is demonstrated that the FTEs prepared via the co-doped system have excellent optoelectronic properties as well as high mechanical stability.

Tri-band and high FOM THz metamaterial absorber for food/agricultural safety sensing applications

Multi-band based terahertz metamaterial absorber is of great importance in current research and applications because of its ability to achieve multi-band absorption of electromagnetic waves and multi-point matching of detection material information. In this paper, a three-band terahertz metamaterial absorber based on metal split-opening ring is proposed, which produces harp peaks with high Q values due to the resonant response of the metal resonator matched with the surface lattice resonance. By optimizing the structure parameters, the Q-factor is as high as 528 and the FOM value is 153.2, which is better than the FOM of the currently reported absorbers. The sensing performance of absorber as refractive index sensor and thickness sensor is studied, and the results show that it can be used for refractive index sensing and thickness sensing detection of analytes. Finally, five pesticides were simulated and tested. The maximum frequency shift of the absorber was 16ghz when the refractive index changed by 0.02 steps, which proved its ability to recognize different pesticides. The detection of proline solutions of 2–10 g/100 ml proves that the absorber could detect analytes with a refractive index difference of 0.003. These results show that the absorber has high sensitivity, high Q factor, ultra-high FOM, and polarization-insensitive characteristics, which can be used for detecting food/agricultural safety testing and other fields.

Fabrication of Flexible and Transparent Metal Mesh Electrodes Using Surface Energy-Directed Assembly Process for Touch Screen Panels and Heaters.

Transparent conductive electrodes (TCEs) are indispensable components of various optoelectronic devices such as displays, touch screen panels, solar cells, and smart windows. To date, the fabrication processes for metal mesh-based TCEs are either costly or having limited resolution and throughput. Here, a two-step surface energy-directed assembly (SEDA) process to efficiently fabricate high resolution silver meshes is introduced. The two-step SEDA process turns from assembly on a functionalized substrate with hydrophilic mesh patterns into assembly on a functionalized substrate with stripe patterns. During the SEDA process, a three-phase contact line pins on the hydrophilic pattern regions while recedes on the hydrophobic non-pattern regions, ensuring that the assembly process can be achieved with excellent selectivity. The necessity of using the two-step SEDA process rather than a one-step SEDA process is demonstrated by both experimental results and theoretical analysis. Utilizing the two-step SEDA process, silver meshes with a line width down to 2µm are assembled on both rigid and flexible substrates. The thickness of the silver meshes can be tuned by varying the withdraw speed and the assembly times. The assembled silver meshes exhibit excellent optoelectronic properties (sheet resistance of 1.79Ω/□, optical transmittance of ≈92%, and a FoM value of 2465) as well as excellent mechanical stability. The applications of the assembled silver meshes in touch screen panels and thermal heaters are demonstrated, implying the potential of using the two-step SEDA process for the fabrication of TCEs for optoelectronic applications.

Highly sensitive fiber SPR sensor based on InSe nanosheets

Surface plasmon resonance (SPR) optical fiber sensors exhibit advantages such as small size, immunity to electromagnetic interference, and corrosion resistance, and are currently widely applied in the field of biodetection. However, their sensitivity and reusability are still limited in detecting biomolecules, trace concentrations, and weak signals. This paper proposes an approach by utilizing indium selenide (InSe) nanoflakes to enhance the surface electric field strength of the metal layer. InSe is a two-dimensional material that exhibits higher charge carrier mobility and refractive index compared to traditional two-dimensional materials, thereby promoting electron transfer and inducing a larger SPR effect. By testing the sensors composed of InSe nanosheets with different thicknesses, it is found that the sensitivity of InSe nanosheets with a thickness of 40 nm is up to 4655.76 nm/RIU, which is much higher than the sensitivity of traditional Au film sensors and 52 % higher than that of MoS2-Au film SPR sensors with the same structure. Moreover, the sensor has a higher FOM value of 33.25 RIU−1 and shows excellent characteristics in repeatability and stability experiments. In this paper, a new method is proposed to enhance the sensitivity of SPR sensors and realize the monitoring of lower biomolecule concentration and weak signal. In addition, the great potential of indium selenide nanosheets in optical applications is emphasized.

Study on the scintillation performance of CLLB:Ce scintillator and optimization of measurement method

In this work, Cs2LiLaBr6:1%Ce (CLLB:Ce) single crystal with the size of Ф26 mm × 80 mm were successfully grown by the Bridgman method. The optimal conditions of application were presented by coupling with R6231-100 PMT. The pulse spectra are recorded by the 4-channel digital converter DT5751 at a sampling rate of 1 GS/s. The energy spectra of the CLLB:Ce crystal were recorded under different PMT gain voltage. The best energy resolution is obtained (up to 3.8%) when the gain voltage of PMT is 3.65V. The non-proportionality of CLLB:Ce crystal was measured under varied radioactive sources while the background radioactive was discussed. Besides, the energy spectra of CLLB:Ce crystal were recorded when the temperature was varied from −30 °C to 50 °C. Finally, the discriminating ability of neutron and gamma was evaluated under 252Cf source and AmBe source, the FOM value is 1.4 and 1.2, respectively, which has a greatly potential application in the nuclear radiation detection.

The effect of thickness on the optical and electrical properties of Hf doped indium oxide thin films

The doping of Hf has great potential to adjust the optical and electrical properties of In2O3 films, which has rarely been reported. In this paper, Hf-doped indium oxide films (IHFO) with excellent optical (average transmittance: 95.81%) and electrical properties (resistivity: 7.1 × 10−4 Ω cm) were deposited by RF sputtering on the glass substrate. X-ray photoelectronic spectra (XPS) showed that Hf4+ substituted In3+, resulting in an increase in carrier concentration and thus decreased resistivity. The X-ray diffraction (XRD) and Scanning electron microscopy (SEM) indicated that the change in the preferred orientation of IHFO film from (400) to (222) leads to different shape grains, which are associated with nuclei merging due to thickness increase. As the optical path of the visible light in film increase with film thickness, the film's visible light absorption is enhanced, resulting in the average transmittance of the films decreasing from 95.81% to 87.68%. Considering the effect of thickness on optical and electrical properties, the IHFO film at a thickness of 893 nm exhibits the highest FOM value of 2.85 × 10−2 Ω−1 with high average transmittance (89.84%) and low sheet resistance(12 Ω/sq). This result indicates that the IHFO film deposited with optimal thickness can be an alternative for high-performance TCO in various optoelectronic fields.

A Low Phase Noise Crystal Oscillator with a Fast Start-Up Bandgap Reference for WLAN Applications

This article presents the design and implementation of a 40 MHz crystal oscillator (XO) with low phase noise, based on the 55 nm CMOS process, for wireless transceiver systems, particularly those used in Wireless Local Area Network (WLAN). The proposed design employs a bandgap reference circuit that includes a start-up circuit and a low-voltage common-source common-gate current mirror, which ensures that the bandgap reference circuit is powered up effectively across all temperatures and process corners. A low-pass filter is also incorporated at the low dropout regulator (LDO) input to reduce the phase noise of the XO circuit. The experimental results demonstrate that the proposed design achieves a final phase noise of −164.36 dBc/Hz at 100 kHz offset frequency, with a power consumption of 0.444 mW. The test of start-up time is 0.718 ms and the compact chip area is 0.088 mm2. According to the simulation and test results, the final FOM value calculated in this paper is 209.93 dBc/Hz at 100 kHz offset.

GaAs-enabled tunable multifunctional devices based on three coupling mechanisms for terahertz metamaterials

In this paper, a terahertz metamaterial structure with multiple physical features such as EIT-like resonance, Fano resonance, and terahertz wave absorption, is implemented. The device consists of a metal structure and a GaAs layer. The conductivity of GaAs can be adjusted by optical pump. When the conductivity of GaAs is 10 S/m, with the TE polarization wave incenting, the Fano resonance formed, and when the TM polarization wave was incenting, the EIT-like resonance formed. Modulation of the resonance can be achieved by adjusting the conductivity of GaAs, and a maximum modulation depth of 96.5% is obtained. When the conductivity of GaAs is 2 × 105 S/m, a double narrow-band absorption is obtained with TM polarization wave exciting. The maximum sensitivity reaches 513 GHz/RIU and the maximum FOM value reaches 39.5, which indicates that the device has excellent performance in refractive index sensing. The device also has a wide range of applications in terahertz sensors, slow-light devices, and terahertz modulators.

A Low Power 100-Gb/s PAM-4 Driver with Linear Distortion Compensation in 65-nm CMOS

This paper proposes a low-power 100Gb/s four-level pulse amplitude modulation driver (PAM-4 Driver) based on linear distortion compensation structure for thin-film Lithium Niobate (LiNbO3) modulators, which manages to achieve high linearity in the output. The inductive peaking technology and open drain structure enable the overall circuit to achieve a 31-GHz bandwidth. With an area of 0.292 mm2, the proposed PAM-4 driver chip is designed in a 65-nm process to achieve power consumption of 37.7 mW. Post-layout simulation results show that the power efficiency is 0.37 mW/Gb/s, RLM is more than 96%, and the FOM value is 8.84.

Simulation and Analysis of Land-Use Change Based on the PLUS Model in the Fuxian Lake Basin (Yunnan–Guizhou Plateau, China)

It is essential to study the characteristics of land use change in the Fuxian Lake basin, a plateau lake in Yunnan Province, and to predict the basin’s future trend of land use change for sustaining the key carriers of current national major strategies such as ecological civilization, green development, and rural revitalization. This study used the Fuxian Lake basin as the subject and based on the seven periods of historical land use data, added six driving factors including human and natural factors, applied patches to generate the land-use simulation model (PLUS), and forecasted and analyzed the characteristics of land-use change in the basin in 2048 under the three scenarios of natural trend development, ecological protection, and production protection. The results showed that: (1) the overall simulation accuracy of the model was 79.14%, Kappa index was 0.73, FOM value was 0.29, and the model’s consistency was high. The model can be used to simulate future land-use changes in the Fuxian Lake basin. (2) In the natural development scenario, land-use development and the driving factors in the basin have the following relationship: rainfall and trunk road distance significantly impacted the types of land that emphasize ecological conservation and product development. Elevation and soil distribution characteristics had a significant impact on land types focused mainly on water zones and ecological protection. The land types mainly focused on urban construction were greatly affected by elevation, trunk road distance, GDP per capita, and other factors. (3) The main direction of land-use change in the watershed is the mutual conversion between farmland and forest land, with the continuous expansion of construction land. In the production protection scenario, the area of farmland increased by 44.79 hm2. In the ecological protection scenario, the area of arbor forest land increased by 37.85 hm2 and the area of shrub forest land decreased by 62.37 hm2. (4) From the perspective of spatial distribution patterns, the regional hotspot change blocks are mainly concentrated in the north of the basin, along the coast of the north of Fuxian Lake, and the southern land. In general, the PLUS model had good applicability in this study. The simulation results of the different scenarios were in line with the land development in the Fuxian Lake basin and can provide scientific reference for land-space planning, ecological and production land constraints, and coordination of development in the Fuxian Lake basin.

Improved frequency response of the 3.5 GHz SMR devices using Ga-doped AlN thin films as the piezoelectric layers

In this paper, the aluminum nitride (AlN) and gallium-doped aluminum nitride (AlGaN) films are adopted to fabricate the 3.5 GHz solidly mounted resonator (SMR) devices. A reactive radio frequency (RF) magnetron sputtering system and a co-puttering subsystem were used to deposit AlN and AlGaN thin films as piezoelectric layers. The sputtering parameters were fixed as sputtering pressure of 35 mTorr and sputtering power of 200 W for AlN piezoelectric layers. For the co-sputtering parameters, the sputtering pressure was set 10 mTorr, and the sputtering powers of Al and GaN targets were 175 W and 25 W, respectively, to deposit AlGaN piezoelectric layers. The X-ray diffraction (XRD) patterns showed that as compared with the 2[Formula: see text] values of the diffraction peaks of AlN thin films, those of AlGaN thin films shifted to lower values. Even the diffraction intensity of (002) peak of AlGaN thin film was higher than that of AlN film, both AlN and AlGaN thin films presented the strongly [Formula: see text]-axis orientated crystallization. The energy dispersive X-ray spectrometer (EDS) analysis showed that the content of Ga element in the AlGaN thin film, ([Formula: see text]), was about 19%. SEM images showed that the obtained AlN and AlGaN thin films exhibited uniform grain sizes and smooth surfaces. Finally, both the frequency responses of the fabricated SMR devices were measured using a network analyzer and the difference in their efficiencies were well compared. The frequency response of the fabricated SMR device with [Formula: see text][Formula: see text]N thin film showed the center frequency of 3.51 GHz, the return loss [Formula: see text] of −10.466 dB, quality factor [Formula: see text] of 170.952, electromechanical coupling coefficient [Formula: see text] of 4.026%, and FoM value of 6.838, respectively. The results show that the frequency response of SMR device has been improved by Ga doped in AlN thin film, although the [Formula: see text] value is still less than that of obtained using single crystalline AlGaN thin film.