This paper proposes a modified uni-traveling-carrier photodiode (MUTC-PD) featuring dual electric field control layers to achieve high-speed and high-responsivity performance at low bias voltages. By incorporating a lightly p-doped InGaAs electric field control layer in the absorption region, combined with a heavily n-doped InP cliff layer, this design can jointly modulate the electric field near the heterojunction to efficiently mitigate the space charge effect. Compared to the original structure without electric field control layers, the 10 µm diameter device exhibits a 67% enhancement in 3 dB bandwidth under − 1 V bias, reaching 55 GHz while maintaining a high responsivity of 0.803 A/W. Under − 4 V bias, the 3 dB bandwidth of the device further increases to 66 GHz.

The ultrawide-bandgap semiconductor Ga2O3, characterized by its high breakdown voltage, demonstrates significant potential for applications in optoelectronics and photonics. In this study, we propose a cost-effective strategy for the scalable production of Al-doped Ga2O3 via post-growth thermal annealing. Our results demonstrate that the binary /3-Ga2O3 films are first alloyed into ternary (201) /3-(AlxGa1-x)2O3 alloys with tunable compositions under optimized annealing conditions, ultimately forming /3-(AlxGa1-x)2O3/Al2O3 heterostructures. Specifically, through X-ray diffraction (XRD) analysis, the Al content of the /3-Ga2O3 template samples without annealing and annealed up to 1300 degrees C ranges from 0 to 0.598, with the optical bandgap tunable from 5.01 eV to 6.30 eV. Moreover, the resulting ultraviolet photodetectors based on these composites exhibit enhanced photoresponse performance, with a low dark current of 16.6 fA, a maximum on/off current ratio of 4.53 x 106, and a remarkable responsivity of 5.48 A/W. This study provides a straightforward and efficient approach for tailoring the bandgap of /3-(AlxGa1-x)2O3 films for deep-ultraviolet optoelectronic applications.

Vortex beams, also known as orbital angular momentum (OAM) beams, possess a helical wavefront phase and have attracted broad interest in optical communication, detection, manipulation and trapping. Reliable detection of OAM modes is essential for practical deployment. Beyond OAM, vortex beams encode information in additional dimensions, such as wavelength. However, conventional optical systems typically rely on bulky components and repeated measurements to extract such multidimensional information, hindering miniaturization and on-chip integration. Here we introduce an ultraviolet (UV) metasurface platform for multidimensional light-field detection. We design a wavelength-multiplexed multifocal metalens operating in the UV band and, on this basis, implement a wavelength-multiplexed vortex-beam sorter that exploits momentum conservation. Beams with different wavelengths and OAM states are mapped to distinct positions in the focal plane, enabling simultaneous sorting of wavelength and OAM. Furthermore, by projecting two OAM modes onto a single focal spot, we achieve single-spot detection of dual OAM modes, substantially increasing the detection capacity of the sorter. Our approach offers a compact and integrable solution for UV vortex-beam analysis, with potential applications in high-resolution imaging, high-capacity optical communication, biomedical sensing and quantum optics.

Gallium oxide, characterized by its ultra-broad bandwidth, high electron drift velocity, and excellent thermal stability, demonstrates significant potential for solar-blind ultraviolet photodetectors (SBUV-PDs) that can be applied in both military and civilian contexts, such as missile warning, fire detection, and secure communications. However, the conventional metal-semiconductor-metal (MSM) structure of photodetectors results in suboptimal responsivity due to reflection and absorption at the metal-semiconductor interfaces, as well as the inability of the semiconductor to effectively optimize light absorption. In this work, we propose a periodic nanopore design in Ga2O3 thin films, which capitalizes the coupling between incident light and the electronic oscillations on the Ga2O3 surface, thereby increasing the effective absorption area as well as inducing optical interference within the structure. Compared to the structure without surface modifications, the photodark current ratio (PDCR) increases by an order of magnitude, from 2.39 & times; 10(7) to 4.26 & times; 10(8), and the responsivity is enhanced by a factor of 5.87, rising from 0.55 to 3.23 A/W. This study is expected to offer a reliable strategy for the fabrication of high-performance SBUV-PDs.

This work presents a physics-based equivalent-circuit model for accurately predicting the frequency response of uni-traveling-carrier photodiodes (UTC-PDs) and enabling design optimization up to the terahertz (THz) band. The model is developed based on a carrier energy-balance transport framework and incorporates both thermal and space-charge effects in a unified manner. Model validation is performed by comparing predicted frequency responses with measurements from fabricated UTC-PDs, demonstrating excellent agreement up to the THz regime. Furthermore, the model provides clear physical insight into the influence of key device parameters on UTC-PD performance, thereby facilitating systematic optimization of UTC-PD designs to achieve optimal performance.

A novel uni-traveling carrier photodiode (UTC-PD) with dual electric field control layers is proposed, which achieves high speed and high responsivity. It demonstrates a 3 dB bandwidth of 57 GHz and a responsivity of 0.803 A/W under a bias voltage of -1 V. The proposed device can be applied for 800 Gb/s optical modules.

Ga2O3 is a transparent oxide dielectric material characterized by low loss, high refractive index, and excellent chemical and thermal stability, suggesting significant potential in other spectral bands beyond ultraviolet detector and power electronics, although few studies have been reported. Herein, we employ Ga2O3 as a dielectric layer to construct a metal-insulator-metal (MIM) symmetric metasurface absorber, which achieves nearly perfect absorption of 99% in the near-infrared band, and can achieve a maximum redshift of 1.009 mu m to 1.349 mu m by changing the parameters of the upper symmetric metal array. Additionally, If the symmetry of the metal array is broken, the Fano effect will be excited, generating multiple resonance peaks in the absorption spectrum, and more than 60% of the average bandwidth absorption will be achieved in the range from 0.844 mu m to 1.130 mu m by the superposition of multiple resonance peaks. More importantly, graphene is introduced into the asymmetric structure, resulting in a dynamic modulation of 0.334 mu m by adjusting the Fermi energy of graphene, while the bandwidth absorption characteristics are retained. This work sheds valuable insight into the Ga2O3-based metasurface absorber, thereby paving the way for near-infrared optoelectronic devices.

Power devices based on Ga2O3 have been widely studied in recent years. Due to the absence of the p-Ga2O3, the performance of the power devices based on Ga2O3 was largely limited. To get better performance, many Ga2O3 Schottky Barrier Diodes (SBD) with edge termination (ET) were proposed. In this work, p-NiO field limiting rings (FLRs) are implanted into Ga2O3 SBD to improve the power figure of merit (P-FOM) and reduce the complexity of the current high-performance edge termination structure manufacturing process. The implantation of the FLRs can weaken the peak electric field strength and extend the depletion zone in the horizontal direction. Further exploring the influence of some parameters of the device on device performance through TCAD simulation, the breakdown voltage (BV)/specific on-resistance (Ron,sp) of SBD with FLRs is up to 5340 V/3.748 m $\Omega \cdot $ cm2, and P-FOM = BV2/Ron,sp can reach 7.61 GW/cm2, and turn-on voltage (Von) of 0.9 V is achieved. The manufacturing process of the presented Ga2O3 SBD with p-NiO FLRs is relatively simple compared to devices with approximate P-FOM values. This kind of Ga2O3 SBD with FLRs has great promise for future high-power applications.

Aluminum alloys are renowned for their lightweight nature, resistance to oxidation, and impressive mechanical properties. Despite these advantages, their mechanical performance deteriorates significantly in extreme environments. Herein, we present an innovative solution by developing aluminum matrix composites (AMCs) that incorporate 3D printed alumina ceramic lattices. Our investigation demonstrates a remarkable 112.4 % increase in the strength of AMCs compared to pure aluminum, with a concurrent 54.8 % improvement in modulus under identical conditions. Additionally, as the volume fraction of the ceramic lattice varies from 0.21 to 0.45, the modulus of AMCs exhibits a noteworthy increase, ranging from 96.2 to 106.5 GPa, surpassing that of pure aluminum (68.8 GPa). Notably, even at temperatures of up to 300 degrees C, the strength of the Al2O3-Al composite matrix remains stable at 477.3 MPa. X-ray computed tomography analysis elucidates that the structural integrity of these composites predominantly relies on the load-bearing capacity of the ceramic lattices, complemented by the damping effect provided by the aluminum matrix. This innovative approach not only paves the way for scalable production of high-strength metal alloys in the industrial sector but also holds promise for substantial economic opportunities in the near future.

Solar-blind ultraviolet photodetectors (SBUV-PDs) are utilized in various military and civilian fields, encompassing missile tracking, high-voltage detection, and fire warning systems. Ga2O3 emerges as the prime candidate for such PDs owing to its elevated bandgap, remarkable thermal stability, and facile fabrication process. The metal-semiconductor-metal (MSM) structure garners attention for its swift response time and straightforward preparation, thus becoming a focal point among diverse PD architectures. Nevertheless, the metal surface impedes optical absorption, thereby diminishing the quantum efficiency of the PD. In this work, we introduce a nanograting onto the Ga2O3 surface, which results in a 747-fold increase in responsivity in the SBUV region compared to a normal MSM grating-free structure. Metal gratings can induce surface plasmon polaritons (SPP), thereby augmenting the optical absorption of the PD and stimulating hot electrons to increase photocurrent. However, the broadband response caused by the introduction of metal gratings is a common problem. By optimizing the doping concentration of the Ga2O3 absorption layer, adjusting the incident light intensity, and reverse voltage, the problem of broadband response has been solved. The responsivity of the device in the non-SBUV region is suppressed 24-fold. This methodology holds promise as a reliable approach for fabricating high-performance SBUV-PDs.

Power devices based on Ga2O3 have been widely studied in recent years. Due to the absence of the p-Ga2O3, the performance of the power devices based on Ga2O3 was largely limited. To get better performance, many Ga2O3 Schottky Barrier Diodes (SBD) with edge termination (ET) were proposed. In this work, p-NiO field limiting rings (FLRs) are implanted into Ga2O3 SBD to improve the power figure of merit (P-FOM) and reduce the complexity of the current high-performance edge termination structure manufacturing process. The implantation of the FLRs can weaken the peak electric field strength and extend the depletion zone in the horizontal direction. Further exploring the influence of some parameters of the device on device performance through TCAD simulation, the breakdown voltage (BV)/specific on-resistance (R-on,R-sp) of SBD with FLRs is up to 5340 V/3.748 m Omega center dot cm(2), and P-FOM = BV2/R-on,R-sp can reach 7.61 GW/cm(2), and turn-on voltage (V-on) of 0.9 V is achieved. The manufacturing process of the presented Ga2O3 SBD with p-NiO FLRs is relatively simple compared to devices with approximate P-FOM values. This kind of Ga2O3 SBD with FLRs has great promise for future high-power applications.

In this Letter, a high-quality and high-resistivity nitrogen (N)-doped Ga2O3 current blocking layer (CBL) is grown utilizing metal-organic chemical vapor deposition homoepitaxial technology. By using nitrous oxide (N2O) as oxygen source for Ga2O3 growth and N source for doping and controlling the growth temperature, the grown CBL can effectively achieve high (similar to 10(19) cm(-3)) or low (similar to 10(17) cm-3) N doping concentrations, as well as high crystal quality. Furthermore, the electrical properties of the developed CBL are verified at the device level, which shows that the device using the CBL can withstand bidirectional voltages exceeding 3.5 kV with very low leakage (<= 1 x 10(-4) A/cm2). This work can pave the way for the realization of high-voltage and low-leakage Ga2O3 vertical devices, especially metal-oxide-semiconductor field effect transistors.

Improvements in phase stability and dielectric characteristics can broaden the applications of zirconia in ceramics. Herein, a series of Y2O3-stabilized zirconia (YSZ) ceramics are synthesized using solid-state sintering, followed by an investigation into their phase evolution, grain size, dielectric constant, and breaking field. As the Y2O3 content increases from 0 wt% to 4 wt%, the as-grown YSZ ceramics undergo a distinct phase transformation, transitioning from monoclinic to monoclinic + tetragonal and further to monoclinic + tetragonal + cubic, before finally returning to monoclinic + cubic. Significant changes occur in the internal microstructure and grain size of the ceramics as the phase composition alters, resulting in a reduction in grain size from 3.17 μm to 0.27 μm. Moreover, their dielectric constants exhibit an increasing trend as the Y2O3 content increases, rising from 3.92 to 13.2. Importantly, the dielectric breakdown field of these YSZ ceramics shows a similar variation to the phase evolution, ranging from 0.11 to 0.15 MV/cm. This study sheds light on the phase evolution and dielectric properties of YSZ ceramics, offering an efficient strategy for enhancing their dielectric performances.

High-performance electro-optic (EO) materials greatly enhance modulators and switches in various photonic applications. We investigate the evolution of the tolerance factor (t) and EO coefficient (rc) in A-site and B-site doped BaTiO3 (BT) thin films. Our analysis reveals that cation transmutation has a remarkable impact on their dielectric constant, spontaneous polarization, optical band gap, and EO coefficient. Notably, Pb-doped BT samples exhibit an even higher rc value of 336.5 pm/V, representing a nearly 60% increase compared to pure BT and approximately 11 times larger than that of LiNbO3. This substantial improvement in EO performance can be attributed to enhanced local structural heterogeneity resulting from cation dopants. Furthermore, infusing dopants in BT also result in good structural uniformity and reliable EO performances, regardless of temperature and frequency. Our study offers valuable insights into doping engineering for obtaining functional perovskite oxides, enabling the development of power-efficient, ultra-compact integrated nanophotonic devices.

The next-generation computing system is required to perform 10(18) floating point operations per second to address the exponential growth of data from sensory terminals, driven by advancements in artificial intelligence and the Internet of Things. Even if a supercomputer possesses the capability to execute these operations, managing heat dissipation becomes a significant challenge when the electronic synapse array reaches a comparable scale with the human neuron network. One potential solution to address thermal hotspots in electronic devices is the use of vertically-aligned hexagonal boron nitride (h-BN) known for its high thermal conductivity. In this study, we have developed textured h-BN films using the high power impulse magnetron sputtering technique. The thermal conductivity of the oriented h-BN film is approximately 354% higher than that of the randomly oriented counterpart. By fabricating electronic synapses based on the textured h-BN thin film, we demonstrate various bio-synaptic plasticity in this device. Our results indicate that orientation engineering can effectively enable h-BN to function as a suitable self-heat dissipation layer, thereby paving the way for future wearable memory devices, solar cells, and neuromorphic devices.

Highly stretchable and mechanically foldable electronic devices such as photodetectors (PDs) have garnered significant attention in recent years. Nevertheless, existing devices in this category often compromise their photosensitivity and/or response time in order to achieve the desired stretchability. Here we present a novel free -standing stretchable photodetector constructed using electrospun ferroelectric P(VDF-TrFE) nanofibers (NFs) adorned with boron nitride quantum dots (BNQDs). The incorporation of BNQDs leads to a remarkable 160.0 % increase in the Young's modulus of the composite NFs and enhances their strain capacity to an impressive 120 %. Furthermore, it significantly augments the photoresponsivity by 847.8 %, primarily attributable to the abundant trap states present in the BNQDs. Additionally, we discovered a strong dependency of the giant photocurrent (Iph) on the channel length (l), whereby Iph approximate to 1/l2. Notably, our fabricated devices exhibit exceptional stretchability, allowing for up to 100 % strain while maintaining a rapid rise time of approximately 15.6 ms and an expeditious decay time of 12.6 ms. Our findings underscore the significant potential of ferroelectric polymer NFs decorated with BNQDs in the realm of flexible optoelectronic applications.

In this work, a novel gallium oxide (Ga2O3) vertical FinFET with integrated Schottky barrier diode (SBD-FinFET), which achieves low conduction losses, is proposed. In the reverse conduction state, the integrated SBD can provide additional low-resistance path to conduct reverse current, hence achieving low reverse conduction loss. In the switching state, the SBD-FinFET can also reduce gate-drain capacitance and gate charge, thus featuring fast switching speed and low switching losses. Furthermore, in the other states, the integrated SBD of the SBD-FinFET is in the OFF state, which does not significantly affect the device characteristics. The well-calibrated simulation results show that when compared with the state-of-the-art FinFET with integrated Fin channel and ohmic contact diode (FOD-FinFET), the SBD-FinFET can reduce reverse conduction loss, turn-on loss, and turn-off loss by 25%, 19%, and 22%, respectively, while other characteristics retain almost unchanged.

Mainstream high-k gate materials, such as SiO2, Al2O3, and HfZrO2, are in demand for modern electronics. However, these dielectrics possess lower thermal conductivity, significantly limiting thermal dissipation in electronic devices. Herein, we propose the utilization of complementary metal-oxide semiconductor- (CMOS) compatible high power impulse magnetron sputtering (HiPIMS) for the mass production of highly textured hexagonal boron nitride (h-BN) on (100)-, (110)-, and (111)-oriented SrTiO3 substrates. The as-prepared films exhibit distinct vertical alignments, as evidenced by HRTEM and FTIR analysis. Notably, the R value, ranging from 0.46 to 0.50, is associated with the stress in the film. Importantly, distinct anisotropies in thermal conductivity, dielectric constant, and optical band gap are observed. Furthermore, the values of thermal conductivity in these highly textured h-BN films are 4.5, 5.7, and 5.3 Wm−1K−1, which is almost three times larger than those of SiO2 (1.4 Wm−1K−1) and Al2O3 (1.35 Wm−1K−1), and even an order of magnitude larger than that of HfZrO2 (0.67 Wm−1K−1). The combination of excellent dielectric characteristics, favorable thermal conductivity, and superior stability over a broad temperature range makes this novel material outperform conventional dielectric gate materials in high-power electronics applications.

AbstractSensors, functioning as primary conveyors of perceptual data, stand ready to illuminate the landscape of the intelligent era. Barium titanate, an exceedingly pivotal class of ferroelectric materials for sensor applications, has attracted considerable attention from both commercial and industrial sectors in recent years. Against this backdrop, this paper embarks on a comprehensive examination of sensors founded upon barium titanate across a spectrum of applications. Our investigation commences with a historical analysis of ferroelectric materials, with a specific emphasis on the developmental trajectory of barium titanate. Subsequently, an in‐depth exposition elucidates the attributes and manufacturing processes linked to barium titanate materials, providing readers with insight into the structural and manufacturing aspects of these materials. Ultimately, we introduce a diverse array of sensors tailored to distinct functions within a myriad of domains.