Mid-infrared polarization detection can significantly enhance target detection capabilities in complex background environments. However, conventional polarization detection methods typically require bulky and complex optical systems. In this work, aluminum gratings at four orientations are directly integrated onto the surface of InSb detectors to achieve linear polarization detection. The InSb photodetector with a spectral reponse ranging from 3 mu m to 5.35 mu m and a detectivity of 5.08 x 1011 cm & sdot;Hz1/2/W at 77 K has been demonstrated. Furthermore, all the integrated gratings at four orientations provide a polarization extinction ratio greater than 41:1, while also reducing reflection losses of the incident light. As a result, the responsivity to linearly polarized light improves from 1.9 A/W for the bare detector to 2.15 A/W with the addition of the SiO2 layer, and further increases to 2.24 A/W with the integration of the grating. This approach offers a promising solution for compact mid-infrared polarization detection.

Abstract In recent years, micro-LEDs have garnered widespread attention as core devices for next-generation display technology. As device dimensions are scaled down to the micrometer range, however, sidewall damage introduced by dry etching has become a critical bottleneck limiting their optoelectronic performance. In this study, InGaN-based micro-LEDs ranging in size from 1 μm to 5 μm were fabricated, and the effects of TMAH sidewall treatment on their optoelectronic characteristics were systematically investigated. The study found that TMAH treatment significantly enhanced the peak wall-plug efficiency (WPE), with an increment exceeding 100% for 1 μm and 2 μm micro-LEDs. Meanwhile, the reverse-biased leakage current of all devices is decreased by approximately one order of magnitude. Electroluminescence (EL) spectra further revealed a pronounced superlattice (SL) emission peak after TMAH chemical treatment, verifying the improved longitudinal current spreading. These findings validate the effectiveness of TMAH sidewall treatment in high-performance micro-LED fabrication.

Ultra-compact spectrometers have attracted significant attention for their potential applications in portable systems for biomedical analysis, environmental monitoring, spectral analysis, and astronomical observation. In this work, we propose a miniaturized InGaAs-based extended short-wave infrared (eSWIR) spectrometer based on a single n-graded-p junction with voltage-tunable optical response characteristics in the range from 1600 to 2100 nm. We combine this unique optical characteristic with a regression algorithm to realize the reconstruction of an unknown spectrum. The spectrometer achieves a high responsivity of 0.73 A/W at 1650 nm, and a low dark current density of 3.91 x 10-5 A/cm2 at 200 K, corresponding to a calculated detectivity of 1.69 x 1011 cm Hz1/2/W. Such spectrometers compatible with standard III-V processes can offer a pathway to greatly promote the development of miniaturized spectrometers. (c) 2026 Chinese Laser Press

The passivation of crystalline silicon surface is extremely crucial and irreplaceable in the preparation of crystalline silicon heterojunction (SHJ) solar cells, and it is highly sensitive to the surface structural configuration and characteristics of the silicon substrate. In this work, we innovatively proposed a hydrophobic modification scheme for the silicon substrate surface by diluted HF solution incorporated into the slow lifting process, in order to optimize the interface characteristics and enhance the photovoltaic performance of the solar cells. This study conducts an in-depth exploration of the surface reaction mechanism of silicon wafers during HF slow lifting process and its impact on solar cell performance. Compared to the conventional slow lifting of deionized water conjugated with the drying of hot air, X-ray photoelectron spectroscopy (XPS) results reveal that a stable hydrogen-terminated surface with minimal oxidation is formed by the strategic surface modification during HF slow lifting process, characterized by the dominant Si 0 peaks and reduced Si-O-Si signals. The reduced contact resistivity ( ρ c ) and series resistance ( R s ) of the solar cells are also shown to be reduced, and the fill factor (FF) and power conversion efficiency (PCE) of SHJ cells are enhanced by 2.2% and 1.9%, respectively. This study presents an economical and practical method to modify the surface bonding configuration of crystalline silicon. It is elucidated how precisely engineered c-Si surface chemistry effectively suppresses substrate oxidation and markedly elevates cell performance, while simultaneously streamlining cleaning and texturing protocols to accelerate manufacturing rhythm.

Superlattices composed of AlAs0.07Sb/AlSb have been successfully grown on GaSb substrates by the molecular beam epitaxy technique, which are suitable for use as barrier layers in nBn or pBn type InAsSb-based mid-wavelength infrared detectors. In order to improve carrier transport efficiency, it is important to carefully optimize the interface roughness layer of the barrier. In this study, we report a method to optimize the interface roughness of the superlattice barrier layer. We focus on optimizing the superlattice period thickness to improve the interface atomic migration state and achieve a smooth interface morphology for potential infrared detector applications. The roughness of the upper and lower interfaces of the superlattice can be effectively reduced by controlling the period thickness to 2.47 nm. The roughness of the upper and lower interfaces measured by X-ray reflectivity (XRR) is 0.589 nm and 0.732 nm, respectively. In addition, the reciprocal space mappings (RSM) of the (004) and (224) planes of AlAs0.07Sb/AlSb superlattices show that the strain relaxation state of the super-lattices grown at 480 degrees C is completely strained and no misfit dislocations are generated, thus resulting in excellent crystalline quality. This systematic method provides valuable insights for the fabrication of highperformance barrier mid-wavelength infrared detectors grown on GaSb substrates.

Short-wave infrared (SWIR) detectors hold significant application potential in fields, such as optical communications, low-light night vision, and LiDAR. In recent years, SWIR detectors have been advancing toward higher integration, enhanced sensitivity, miniaturization, and lower power consumption. Utilizing the precise control of optical wavefront phase and amplitude by metasurfaces enables efficient light focusing. This work proposes a scheme for the direct on-chip integration of a solid-immersion metalens with an InGaAs/InP PIN infrared detector. The integrated metalens-enhanced detector achieves a 2.4-fold improvement in responsivity compared to the detectors without metalens within the communication band and yields a specific detectivity of 2.37 × 1011 cm Hz1/2/W. This approach significantly enhances detector responsivity without introducing additional dark current or capacitance, thereby paving the way for the development of highly sensitive and miniaturized infrared detectors.

Terahertz (THz) technology has shown significant potential in communication, imaging, and biomedicine due to its unique electromagnetic properties. However, conventional photoconductive antennas (PCAs) based on an InP substrate still face challenges such as material limitations and electric field attenuation. This study presents a novel mesa-structured InP-based PCA, utilizing migration-enhanced epitaxy (MEE) to grow (InAs)4(GaAs)3/ InAlAs short-period superlattices and wet chemical etching for electrode optimization. Finite element method (FEM) simulations revealed that the mesa structure aligns the electric field parallel to the photoconductive layer, ensuring uniform electric field distribution across multiple quantum wells, suppressing dark current and enhancing photocurrent efficiency. Experimental results demonstrated a light-to-dark current ratio of 8.3 for the mesa-structure, with a 4.54-fold improvement in effective photocurrent density, a 90 % reduction in dark current and a Terahertz radiation power boosted by a factor of 4 compared to planar designs. Furthermore, the integration of a distributed Bragg reflector (DBR) enhances optical absorption, leading to an effective photocurrent output of 427 mu A under 1.55 mu m femtosecond laser excitation. This work provides a promising approach for developing high-performance, compact THz sources.

Radiation-induced dermatitis (RID) remains one of the most prevalent and therapeutically challenging complications in cancer radiotherapy, significantly impairing patient quality of life and treatment adherence. In recent years, bioengineered materials have emerged as promising platforms for the prevention and treatment of RID through multifunctional mechanisms. This review systematically summarizes the current landscape of biomaterials applied to radiation-induced skin injury, focusing on the regulation of oxidative stress, inflammatory responses, and regenerative tissue repair. Beyond conventional classifications based on function—such as barrier protection, therapeutic delivery, and tissue reconstruction—we highlight advances in biomaterial design mechanisms. Particular attention is given to surface properties, including roughness, electrical charge, and crosslinking dynamics, which influence immune modulation and cellular behavior at the wound interface. Mechanistic insights are discussed regarding reactive oxygen species-responsive materials, macrophage phenotype regulation, and vascular regeneration in irradiated tissue environments. Comparative analyses with conventional wound dressings, such as alginate-based and silver-containing materials, underscore the superior therapeutic efficacy of biointeractive and stimuli-responsive systems. In addition, emerging technologies including three-dimensional bioprinting, exosome-inspired scaffolds, and multi-responsive drug carriers are critically evaluated for their translational potential. Clinical trials, regulatory pathways, and manufacturing considerations are also discussed to outline future directions for clinical implementation. This review provides a comprehensive and mechanism-driven perspective on next-generation biomaterials for precision treatment of radiation-induced skin damage.

This work conducted a series of explorations on the growth conditions for N-polar GaN films by MOCVD, including misorientation angle, V/III and thickness of low-temperature GaN layer (LT-GaN) and V/III of GaN buffer. To attain the two-dimensional growth pattern more effectively, a 20 nm LT-GaN layer was grown under low V/III (939) without annealing conditions, which achieved the best crystal quality. We found that 4 degrees or 3 degrees misorientation angle leads to an increase in screw dislocations but a significant reduction in edge dislocations compared to a smaller 2(degrees) misorientation angle. We speculated that larger misorientation angles produce larger, more undulating, and fewer LT-GaN islands. Under the same experimental conditions, the crystal quality obtained with an A-misorientation sapphire substrate was similar to that of an M-misorientation sapphire substrate, but the surface was superior. For GaN buffer growth, a high V/III ratio (1643) resulted in poorer crystal quality but obtained a smooth surface with small fluctuations (RMS <1 nm), possibly due to atoms migrating further and weaker 3D growth.

This study demonstrates the critical role of integrating energy band engineering with asymmetric composite passivation structures in enhancing silicon heterojunction (SHJ) solar cell performance. By investigating the effect of deposition pressure on the optical bandgap of pure silane passivation layers, tunable bandgap values ranging from 1.65 to 1.89 eV were achieved. This pressure-induced bandgap modulation enabled the implementation of asymmetric energy band engineering at the c-Si/a-Si:H interface, reducing the band offset from 0.50 to 0.30 eV and increasing the effective minority carrier lifetime by 29%. The optimized SHJ solar cells exhibited an open-circuit voltage (Voc) of 734.8 mV and a fill factor of 85.08%, reflecting respective improvements of 3.0% and 3.5%, and a power conversion efficiency of 24.2% on G12 half-area wafers. These results confirm that energy band engineering of asymmetric composite passivation layers effectively balances passivation quality and carrier transport, significantly enhancing device performance.

To improve the photovoltaic conversion efficiency (PCE) of silicon heterojunction (SHJ) solar cells, this study focuses on optimizing the physical parameters of the sun-side doped layer and proposes strategies to address the challenges posed by Fermi level pinning in wide bandgap designs. Using AFORS-HET simulations, we systematically investigate the effects of bandgap width, doping concentration, and defect state distribution on the energy band structure, interface electric field, and carrier transport dynamics. The results reveal that maintaining the Fermi level within 0.3 eV of the conduction band is essential for optimal device performance. A wider bandgap (>1.8 eV) enhances the utilization of short-wavelength light and significantly suppresses interface recombination, leading to an increase in short-circuit current density ( Jsc ) by 0.8 mA/cm 2 . This benefit comes with a delicate balance between minimizing defect state density and improving doping efficiency. This study provides theoretical insights into the optimization of doped layer physical parameters and proposes practical solutions, including nano-crystallization and low-doping interface strategies, to improve the performance of SHJ solar cells and support industrial applications.

High-temperature electronic materials and devices are highly sought after for advanced applications in aerospace, high-speed automobiles, and deep-well drilling, where active or passive cooling mechanisms are either insufficient or impractical. 2D materials (2DMs) represent promising alternatives to traditional silicon and wide-bandgap semiconductors (WBG) for nanoscale electronic devices operating under high-temperature conditions. The development of robust interfaces is essential for ensuring that 2DMs and their devices achieve high performance and maintain stability when subjected to elevated temperatures. This review summarizes recent advancements in the interface engineering of 2DMs for high-temperature electronic devices. Initially, the limitations of conventional silicon-based materials and WBG semiconductors, alongside the advantages offered by 2DMs, are examined. Subsequently, strategies for interface engineering to enhance the stability of 2DMs and the performance of their devices are detailed. Furthermore, various interface-engineered 2D high-temperature devices, including transistors, optoelectronic devices, sensors, memristors, and neuromorphic devices, are reviewed. Finally, a forward-looking perspective on future 2D high-temperature electronics is presented. This review offers valuable insights into emerging 2DMs and their applications in high-temperature environments from both fundamental and practical perspectives.

We used metal organic chemical vapor deposition (MOCVD) to grow germane (GeH4) doped N-polar GaN on sapphire substrates with misorientations of 2 degrees and 3 degrees off A-plane (2A and 3A). At a GeH4 doping flow rate of 156 nmol min-1, a carrier concentration of 1.46 x 1020 cm-3 was achieved, and the surface morphology and crystal quality show almost no deterioration compared with undoped N-polar GaN (RMS = 0.821 nm and electron mobility mu = 89 cm2 V-1 s-1). As the GeH4 flow rate increases, the doping concentration increases while the mobility decreases, and the surface morphology and crystal quality are less affected. However, if an excessively high doping flow rate is applied, the crystal quality will deteriorate, and pits will appear on the surface. The results of Raman spectroscopy show that as the doping flow rate increases, the compressive stress first increases and then decreases. We compared the GeH4 doping of N-polar, Ga-polar, and non-polar GaN. At the same n++ doping level, only the N-polar GaN can maintain excellent crystal quality and surface undulation, which has important application potential for devices requiring heavily doped layers in the future.

Mid-wavelength infrared (MWIR) detectors offer significant potential for applications in gas sensing, molecular spectroscopy, and remote sensing. Recently, there has been a trend towards the integration, multifunctionality, lightweight design, miniaturization, and power consumption reduction for MWIR detectors. To this end, various strategies have been explored, including the introduction of new materials, such as InAsSb-based materials or two-dimensional materials. Beyond material innovation, here we monolithically integrated a metalens onto the backside of an InAs/GaSb type-II superlattice (T2SL) detector. The detector with metalens achieves a 6-fold enhancement in responsivity with a detectivity of 3.0×10 9 cmHz/W at 300 K. The signal-to-noise ratio of the detector with metalens is improved by an average of 8.2 dB over the temperature range of 77 K to 300 K. This design represents a promising strategy for achieving high-operating-temperature MWIR detectors, facilitating the realization of miniaturization and lightweight IR detection system.

Abnormal photoluminescence (PL) behaviors are observed in the indium gallium nitride (InGaN) light-emitting diodes (LEDs) with high luminous efficiency. The integral PL intensities pumped by a 405 nm laser in these with temperature ramping from similar to 15 K to 300 K, show an abnormal enhancement in the middle temperature range. It differs from the typical monotonous decline trend of PL integral intensity as temperature increases. modified model describing the carrier transportations between InGaN quantum dots (QDs) has been proposed this study. The InGaN QDs have also been observed by transmission electron microscopy (TEM). This provides deep insights into fabricating InGaN light emitting devices with high luminous efficiency.

In this work, we studied the direct epitaxial growth of a-plane GaN on r-plane sapphire substrates with SiO2 stripe-patterned mask oriented along the cGaN direction. By optimizing growth parameters of the GaN on stripes, the film coalescence thickness was reduced to 8 mu m, significantly improving the crystal quality and reducing the anisotropy in both crystal quality and surface morphology. The X-ray rocking curve full width at half maximum values were 345 arcsec along the c-axis and 276 arcsec along the m-axis, respectively. Cross-sectional scanning electron microscopy results suggest that the improvement in crystal quality can be attributed to the annihilation and termination of dislocations at voids formed during GaN lateral growth coalescence. Compared with a-plane GaN films grown on planar sapphire substrates, low-temperature photoluminescence measurements and modified Williamson-Hall analyses further confirmed the enhancement in crystal quality and the reduction in the density of basal stacking faults. This work presents a highly promising approach for the efficient growth of highquality a-plane GaN films through a simple single-epitaxy process without regrowth.

Quantum confinement is recognized to be an inherent property in low-dimensional structures. Traditionally, it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels. However, our previous research has revealed efficient carrier escape in low-dimensional structures, contradicting this conventional understanding.In this study, we review the energy band structure of quantum wells along the growth direction considering it as a superposition of the bulk material dispersion and quantization energy dispersion resulting from the quantum confinement across the whole Brillouin zone. By accounting for all wave vectors, we obtain a certain distribution of carrier energy at each quantized energy level, giving rise to the energy subbands. These results enable carriers to escape from the well under the influence of an electric field. Additionally, we have compiled a comprehensive summary of various energy band scenarios in quantum well structures relevant to carrier transport. Such a new interpretation holds significant value in deepening our comprehension of low-dimensional energy bands, discovering new physical phenomena, and designing novel devices with superior performance.

N-polar GaN film was obtained by using a high-temperature AlN buffer layer. It was found that the polarity could be inverted by a thin low-temperature AlN interlayer with the same V/III ratio as that of the high-temperature AlN layer. Continuing to increase the V/III ratio of the low-temperature AlN interlayer, the Ga-polarity of GaN film was inverted to N-polarity again but the crystal quality and surface roughness of GaN film greatly deteriorated. Finally, we analyzed the chemical environment of the AlN layer by x-ray photoelectron spectroscopy (XPS), which provides a new direction for the control of GaN polarity.

This investigation explores the structural and electronic properties of low-temperature-grown (InAs)4(GaAs)3/Be-doped InAlAs and InGaAs/Be-doped InAlAs multiple quantum wells (MQWs), utilizing migration-enhanced epitaxy (MEE) and conventional molecular beam epitaxy (MBE) growth mode. Through comprehensive characterization methods including transmission electron microscopy (TEM), Raman spectroscopy, atomic force microscopy (AFM), pump–probe transient reflectivity, and Hall effect measurements, the study reveals significant distinctions between the two types of MQWs. The (InAs)4(GaAs)3/Be-doped InAlAs MQWs grown via the MEE mode exhibit enhanced periodicity and interface quality over the InGaAs/Be-InAlAs MQWs grown through the conventional molecule beam epitaxy (MBE) mode, as evidenced by TEM. The AFM results indicate lower surface roughness for the (InAs)4(GaAs)3/Be-doped InAlAs MQWs by using the MEE mode. Raman spectroscopy reveals weaker disorder-activated modes in the (InAs)4(GaAs)3/Be-doped InAlAs MQWs by using the MEE mode. This originates from utilizing the (InAs)4(GaAs)3 short period superlattices rather than InGaAs, which suppresses the arbitrary distribution of Ga and In atoms during the InGaAs growth. Furthermore, pump–probe transient reflectivity measurements show shorter carrier lifetimes in the (InAs)4(GaAs)3/Be-doped InAlAs MQWs, attributed to a higher density of antisite defects. It is noteworthy that room temperature Hall measurements imply that the mobility of (InAs)4(GaAs)3/Be-doped InAlAs MQWs grown at a low temperature of 250 °C via the MEE mode is superior to that of InGaAs/Be-doped InAlAs MQWs grown in the conventional MBE growth mode, reaching 2230 cm2/V.s. The reason for the higher mobility of (InAs)4(GaAs)3/Be-doped InAlAs MQWs is that this short-period superlattice structure can effectively suppress alloy scattering caused by the arbitrary distribution of In and Ga atoms during the growth process of the InGaAs ternary alloy. These results exhibit the promise of the MEE growth approach for growing high-performance MQWs for advanced optoelectronic applications, notably for high-speed optoelectronic devices like THz photoconductive antennas.

The growth of InGaAs quantum wells (QWs) epitaxially on InP substrates is of great interest due to their wide application in optoelectronic devices. However, conventional molecular beam epitaxy requires substrate temperatures between 400 and 500 °C, which can lead to disorder scattering, dopant diffusion, and interface roughening, adversely affecting device performance. Lower growth temperatures enable the fabrication of high-speed optoelectronic devices by increasing arsenic antisite defects and reducing carrier lifetimes. This work investigates the low-temperature epitaxial growth of InAs/GaAs short-period superlattices as an ordered replacement for InGaAs quantum wells, using migration-enhanced epitaxy (MEE) with low growth temperatures down to 200–250 °C. The InAs/GaAs multi-quantum wells with InAlAs barriers using MEE grown at 230 °C show good single crystals with sharp interfaces, without mismatch dislocations found. The Raman results reveal that the MEE mode enables the growth of (InAs)4(GaAs)3/InAlAs QWs with excellent periodicity, effectively reducing alloy scattering. The room temperature (RT) photoluminescence (PL) measurement shows the strong PL responses with narrow peaks, revealing the good quality of the MEE-grown QWs. The RT electron mobility of the sample grown in low-temperature MEE mode is as high as 2100 cm2/V∗s. In addition, the photoexcited band-edge carrier lifetime was about 3.3 ps at RT. The high-quality superlattices obtained confirm MEE’s effectiveness for enabling advanced III-V device structures at reduced temperatures. This promises improved performance for applications in areas such as high-speed transistors, terahertz imaging, and optical communications.