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Thin film lithium niobate is one of the most crucial platforms in the next generation of integrated optoelectronics because of its ability to integrate tight optical confinement, low optical loss, and active optical functions. A current challenge in the field of thin film lithium niobate photonics is the development of high‐performance photodetectors to achieve multifunctional photonic integrated circuits. This study introduces a high‐performance MoTe2 photodetector integrated on a thin film lithium niobate waveguide. The photodetector achieves the lowest dark current and highest on/off ratio among waveguide‐integrated photodetectors on a thin film lithium niobate platform. Due to a slight asymmetry in the behavior of the two electrode contacts of the device, the photodetector also achieves self‐driven. At zero bias and a wavelength of 1310 nm, a dark current of ≈20 pA, and an on/off ratio exceeding 105 are achieved. At a bias voltage of 1 V, the measured dark current, responsivity, and on/off ratio are 1.13 nA, 309 mA/W, and 1.8 × 104, respectively. Notably, the device exhibits fast rise and fall times of 9.3 and 13.5 µs, respectively, accompanied by a high detectivity of 2.58 × 1011 W−1. [ABSTRACT FROM AUTHOR]

Heterojunctions combining 2D and 3D perovskites have caused a surge in the research on X‐ray detectors. The enhanced charge transport facilitated by the built‐in electric field further amplifies the potential of this material system, paving the way for highly sensitive and efficient X‐ray detectors. In this study, PA2PbBr4 single‐crystal film with a thickness of 10 µm is successfully grown on the surface of MAPbBr3 substrate via liquid phase epitaxial method, forming a 2D/3D heterojunction. This innovative detector exhibits a dramatically enhanced sensitivity of 3.81 × 104 µC Gy−1 cm−2 at an X‐ray tube voltage of 70 keV and a bias of 50 V mm−1, along with an ultra‐low detection limit of 11.84 nGy s−1, surpassing the performance of the conventional MAPbBr3 X‐ray detectors by a factor of four and 2 × 103 times higher than that of commercialized α‐Se detectors. Furthermore, the 2D/3D heterojunction exhibits exceptional self‐powered X‐ray detection capabilities, achieving a remarkable sensitivity of 3562.26 µC Gy−1 cm−2 at 70 keV X‐ray tube voltage. This superior performance implies reduced energy consumption, high portability, decreased ion migration, and provides inspiration for the next generation of high‐performance X‐ray detectors. [ABSTRACT FROM AUTHOR]

Human–machine interactions (HMIs) have penetrated into various academic and industrial fields, such as robotics, virtual reality, and wearable electronics. However, the practical application of most human–machine interfaces faces notable obstacles due to their complex structure and materials, high power consumption, limited effective skin adhesion, and high cost. Herein, we report a self-powered, skin adhesive, and flexible human–machine interface based on a triboelectric nanogenerator (SSFHMI). Characterized by its simple structure and low cost, the SSFHMI can easily convert touch stimuli into a stable electrical signal at the trigger pressure from a finger touch, without requiring an external power supply. A skeleton spacer has been specially designed in order to increase the stability and homogeneity of the output signals of each TENG unit and prevent crosstalk between them. Moreover, we constructed a hydrogel adhesive interface with skin-adhesive properties to adapt to easy wear on complex human body surfaces. By integrating the SSFHMI with a microcontroller, a programmable touch operation platform has been constructed that is capable of multiple interactions. These include medical calling, music media playback, security unlocking, and electronic piano playing. This self-powered, cost-effective SSFHMI holds potential relevance for the next generation of highly integrated and sustainable portable smart electronic products and applications. [ABSTRACT FROM AUTHOR]

Polarization‐sensitive photodetectors have garnered significant interest due to their promising applications in navigation, remote sensing, and optical communication. However, conventional polarized light detectors relying on optical filters face challenges due to intricate fabrication and calibration procedures. While structures based on in‐plane anisotropic 2D materials have the potential to offer viable solutions for polarization detection, achieving both low power consumption and high performance remains challenging. Herein, a self‐powered anisotropic/isotropic ReS2/SnSe2 van der Waals (vdWs) heterojunction detector with high‐performance features is constructed. This device exhibits outstanding photovoltaic (PV) performance across a wide spectral range from 405 to 850 nm without bias, featuring excellent responsivity (0.966 A W−1) and specific detectivity (1.47 × 1010 Jones) under 650 nm laser illumination. Moreover, benefiting from the built‐in electric field that promotes carrier separation and extremely low dark current, the device shows fast response time (230/240 µs) with an on/off ratio of up to 104. Furthermore, the ReS2/SnSe2 photodetector demonstrates exceptional polarization encoding performance, with a polarization ratio of 1.56 under 650 nm illumination, opening up new possibilities in optical communication technology development. This research provides a novel and viable option for developing energy‐efficient and high‐performance polarization‐sensitive detectors. [ABSTRACT FROM AUTHOR]

High‐energy excitons in transition metal dichalcogenides (TMDs), resulting from intrinsic van Hove singularities in the density of states, demonstrate strong ultraviolet light absorption capacity and significant potential for the development of high‐performance ultraviolet photovoltaic devices. Nevertheless, only a limited fraction of carriers from high‐energy excitons can be effectively utilized due to unique parallel band structures and unfavorable recombination processes. To efficiently exploit the high‐energy excitons, a two‐terminal photodetector based on multilayer WSe2 with a unilateral Schottky junction is designed. Benefiting from the strong built‐in electric field, a superior responsivity of 286 mA W−1 and near‐unity external‐quantum‐efficiency (EQE) of 98% is achieved at 360 nm. Transient absorption spectroscopy demonstrates that the high EQE is attributed to the efficient separation and transfer of high‐energy excitons achieved by the strong built‐in electric field, thus circumventing unfavorable recombination processes and enabling highly efficient utilization of high‐energy excitons. This work provides an effective strategy for constructing high‐performance and low‐power consumption ultraviolet photodetectors. [ABSTRACT FROM AUTHOR]

2D materials have garnered significant research attention due to their unique electrical and optical properties. Various photodetectors (PDs) based on 2D materials have been demonstrated to possess a high photoresponse, achieve specific light detection, and construct flexible devices. Among these, photoelectrochemical‐type (PEC) PDs are attracting increasing attention due to their facile fabrication processes, self‐powered capability, and high sensitivity. Compared with transitional solid‐state PDs based on 2D materials, research on 2D material‐based PEC PDs is still in its initial stages but exhibits promising potential for various applications. This paper comprehensively reviews recent advancements in 2D material‐based PEC PDs. The 2D materials for PEC PDs are first classified, and then the synthesis methods employed for their fabrication are briefly summarized. Later, the performance and performance optimization strategies of various 2D material‐based PEC PDs are discussed. Finally, the challenges and opportunities for developing high‐performance 2D material‐based PEC PDs are highlighted. [ABSTRACT FROM AUTHOR]

Vertical semiconductor van der Waals heterojunctions are essential for fabricating high-performance photodetectors. However, the range of the spectral response and defect states of semiconductor materials are two critical factors affecting the performance of photodetectors. In this work, the spectral response range of WS2 was changed through WS2 band gap regulation, and a self-powered vertical WS1.08Se0.92/Si heterojunction photodetector with MXene electrode was prepared by synthesizing WS1.08Se0.92 film on Si substrate and vertically stacking Ti3C2T x MXene on the film. Due to the electron collection of MXene and the wonderful junction quality of WS1.08Se0.92/Si, the photodetector can detect near-infrared light in the range of 980–1310 nm, which exceed the detection limit of WS1.08Se0.92. And the device had high sensitivity in the broadband. The responsivity was 4.58 A W−1, the specific detectivity was 4.58 × 1011 Jones, the on/off ratio was 4.95 × 103, and the fast response time was 9.81/9.03 μ s. These properties are superior to previously reported WS2-based photodetectors. Vertical structure, Energy band tuning, and MXene electrode provide a new idea for preparing broadband high-performance and self-powered photodetector. [ABSTRACT FROM AUTHOR]

The combination of the antisolvent method and additive passivation is an effective strategy to control the defects of organic-inorganic halide perovskite films. In this paper, CsSn0.2Pb0.8I3 QDs prepared by the mixed heating method were mixed with toluene solution to form an anti-solvent of different concentrations, and defect passivation and modification of self-supplied carbon-based MAPbI3 perovskite films were carried out. The results show that when the optimal additive concentration of 10 mg/mL CsSn0.2Pb0.8I3 QDs optimized perovskite active layer is applied to the self-powered perovskite photodetector, the original dark current of the device is reduced from 1.09 × 10− 9 A to 5.03 × 10− 11 A, which is about 95%. Responsiveness reaches a maximum of 0.45 A/W, which is 28% higher than 0.35 A/W before optimization. Compared with the detection rate increased from 2.72 × 1012 Jones to 2.53 × 1013 Jones (1 Jones = 1 cm∙Hz1/2∙W− 1), the detection capability of self-powered perovskite photodetector has been improved by nearly one order of magnitude. [ABSTRACT FROM AUTHOR]

Sn and S are environmentally friendly elements that are abundant in nature. The SnS 2 compound formed with these elements has intrinsic n-type electrical conductivity and a direct forbidden band gap of ∼2.2 eV. Therefore, it is a very promising compound for visible light optoelectronic applications. In this study, SnS 2 thin films were coated on p-Si substrates and pn heterojunction structures were obtained. By adding certain amounts of Na element to SnS 2 , the photosensitivity of the heterojunction devices increased tremendously and reached a high value of 3.2 × 104 under zero bias condition. It was observed that the prepared devices had excellent speeds and stability with rise and decay times of as low as 28 m s and 23 m s. Moreover, the devices were found to be sensitive to visible light even at ultra-low light intensity of ∼0.3 μW/cm2. Furthermore, the responsivity and specific detectivity values of the prepared photodetectors reach very high values of 11 A/W and 8.4 × 1013 Jones at this low light intensity. The NEP value drops to a low level of 2.7 × 10−15 WHz −1/2. In addition, the photocatalytic properties of Na-doped and undoped SnS 2 compound were also examined under visible LED light. Compared to undoped samples, photocatalytic efficiency increased by ∼42 % in Na-doped SnS 2 thin films. The findings clearly reveal that Na improves both photodetector device performance and the photocatalytic effect of the SnS 2 semiconductor. [ABSTRACT FROM AUTHOR]

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Harvesting energy through light radiation is an attractive solution for powering wireless devices in the future. In particular, self-driven optoelectronic devices are especially attractive for low-energy devices on the Internet of Things. Two-dimensional (2D) materials at atomic scale thicknesses are very attractive for future self-powered optoelectronic devices due to not only their unique electronic and optical properties, but also the feasibility to fabricate desirable heterostructures, which differ from their bulk counterparts and conventional optoelectronic materials. In this review, we mainly summarized the mechanism and performance of self-powered optoelectronic devices based on 2D materials. The figure of merit and mechanism of self-driving optoelectronic devices including the interface-junction effect, bulk photovoltaic effect, and photothermoelectric effect are discussed in detail. In addition, the recent progress on the performance of self-powered optoelectronic devices based on 2D materials is compared, followed by the perspective of this field. This review is aimed to give a generalized knowledge of 2D self-powered optoelectronic devices, and thus prompt the exploration and development of novel functional devices based on 2D materials. [ABSTRACT FROM AUTHOR]

Wearable sensors are important components, converting mechanical vibration energy into electrical signals or other forms of output, which are widely used in healthcare, disaster warning, and transportation. However, the reliance on batteries limits the portability of wearable sensors and hinders their application in the field of Internet of Things. To solve this problem, we designed a miniaturized high-performance hybrid nanogenerator (MHP-HNG), which combined the functions of triboelectric sensing and electromagnetic power generation as well as the advantages of miniaturization. By optimizing the design of TENG and EMG, the wearable sensor achieved a voltage output of 14.14 V and a power output of 49 mW. Based on the wireless optical communication and wireless communication technologies, the wearable sensor achieved the integration of sensing, communication, and self-powered function, which is expected to realize health monitoring, emergency warning, and rehabilitation assistance, and further extend the potential application value in the medical field. [ABSTRACT FROM AUTHOR]

Van der Waals heterostructures (vdWHs) consisting of 2D materials offer a practical and effective approach for engineering multifunctional, high‐performance photodetectors. However, 2D vdWHs photodetectors based on photoconductive effects require an external power input and are often accompanied by a large dark current, which hinders the development of miniaturization and portability of devices and greatly limits the application of devices in complex environments. Herein, a self‐powered photodetector constructed from an InSe/PtS2 vdWH with an extremely low dark current (≈10−14 A) at zero bias and a large rectification ratio of 5.1 × 103 is reported. Leveraging the robust built‐in electric field of the InSe/PtS2 vdWH, the device demonstrates pronounced photovoltaic effects, characterized by an open‐circuit voltage of 0.395 V and a substantial short‐circuit current of 37.1 nA. Remarkably, a high responsivity and detectivity of 211 mA W−1 and 8.58 × 1012 Jones, an excellent light on/off ratio of 0.8 × 107 , and a fast response time of 465/470 µs are achieved, at zero bias. The device showcases a broadband self‐powered photoresponse spanning from 265 to 1064 nm. This study demonstrates the high potential of the InSe/PtS2 vdWH for broadband self‐powered photodetector applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Flexible self-powered bioelectronics (FSPBs), incorporating flexible electronic features in biomedical applications, have revolutionized the human–machine interface since they hold the potential to offer natural and seamless human interactions while overcoming the limitations of battery-dependent power sources. Furthermore, as biosensors or actuators, FSPBs can dynamically monitor physiological signals to reveal real-time health abnormalities and provide timely and precise treatments. Therefore, FSPBs are increasingly shaping the landscape of health monitoring and disease treatment, weaving a sophisticated and personalized bond between humans and health management. Here, we examine the recent advanced progress of FSPBs in developing working mechanisms, design strategies, and structural configurations toward personalized health management, emphasizing its role in clinical medical scenarios from biophysical/biochemical sensors for sensing diagnosis to robust/biodegradable actuators for intervention therapy. Future perspectives on the challenges and opportunities in emerging multifunctional FSPBs for the next-generation health management systems are also forecasted. [ABSTRACT FROM AUTHOR]

The discovery of triboelectric nano-generators (TENGs) has resulted in the invention and development of self-powered electronics and devices. TENGs offer numerous benefits including their portability, affordability, and sustainable micro-scale energy harvesting in the realm of self-powered sensors and portable devices. TENGs have the capability to function as an autonomous power source. Integration of TENG with electrochemical processes can facilitate self-powered electrochemistry such as water splitting (or electrolysis) for H 2 production, thereby eliminating the requirement for an external power supply. This review primarily centers on the operation and the recent advancements of TENGs in self-powered water-splitting for clean and environment-friendly H 2 production utilizing renewable energy sources including wind, wave, and low-scale mechanical energy. The concept of conducting water-splitting without reliance on an external power source holds the potential for significant use in the field of clean and green H 2 production with cost advantages, sustainability, and other environmental benefits. [Display omitted] • Analysis of principle and working of triboelectric nano-generators (TENGs). • Utilization of TENGs in self-powered water splitting devices. • Review on the recent advances in conversion of wind, wave and low-scale mechanical energy by TENG to clean and green H 2 production. • Summarized benefits, challenges and perspective of TENG based self-powered electrolysis. [ABSTRACT FROM AUTHOR]

The integration of electrochromic devices and energy storage systems in wearable electronics is highly desirable yet challenging, because self‐powered electrochromic devices often require an open system design for continuous replenishment of the strong oxidants to enable the coloring/bleaching processes. A self‐powered electrochromic device has been developed with a close configuration by integrating a Zn/MnO2 ionic battery into the Prussian blue (PB)‐based electrochromic system. Zn and MnO2 electrodes, as dual shared electrodes, the former one can reduce the PB electrode to the Prussian white (PW) electrode and serves as the anode in the battery; the latter electrode can oxidize the PW electrode to its initial state and acts as the cathode in the battery. The bleaching/coloring processes are driven by the gradient potential between Zn/PB and PW/MnO2 electrodes. The as‐prepared Zn||PB||MnO2 system demonstrates superior electrochromic performance, including excellent optical contrast (80.6%), fast self‐bleaching/coloring speed (2.0/3.2 s for bleaching/coloring), and long‐term self‐powered electrochromic cycles. An air‐working Zn||PB||MnO2 device is also developed with a 70.3% optical contrast, fast switching speed (2.2/4.8 s for bleaching/coloring), and over 80 self‐bleaching/coloring cycles. Furthermore, the closed nature enables the fabrication of various flexible electrochromic devices, exhibiting great potentials for the next‐generation wearable electrochromic devices. [ABSTRACT FROM AUTHOR]

The moisture‐enabled electricity generators (MEGs) represent an appealing clean power strategy within the realm of hydrovoltaic technology. However, their stable operation under all‐weather conditions is still challengeable due to the effect of ambient humidity. Herein, a self‐water‐storage MEGs with multifunctionality was developed. Gel textiles are employed as the proton‐release layer, while graphite fibers loaded with tin‐bismuth alloy liquid metal serve as water‐storing electrode. The gel textiles absorb water permeating down from the electrodes, releasing protons, which then react with the active electrode to enhance output performance. The experiment demonstrates that a device can generate a voltage of 0.55 V and a current of 7.08 μA after water storage, with a maximum power density of 1.14 μW·cm‐². The device's performance output can remain stable within a wide temperature range. The experiment confirms that the electrical output of the device originates from ionic diffusion, while density functional theory (DFT) and molecular dynamics (MD) calculations reveal the importance of the strong hydrolysis ability of the polymer and the high adsorption energy of the liquid metal for H3O+ on the output performance of the device. Furthermore, the integrated device has demonstrated effective applications in driving microelectronic devices, charging capacitors and, self‐powered health monitoring. [ABSTRACT FROM AUTHOR]

Recently, IoT-based sensor networks for monitoring environmental parameters have attracted research and development groups due to their numerous advantages. However, these battery-powered devices experience the difficulties of periodic recharge or replacement. Therefore, to provide a sustainable and continuous power supply, piezoelectric energy harvesters can be used where the wired power connection is not feasible due to inaccessible setup or hazardous environment. The efficiency of piezoelectric converters is determined by their geometrical configuration and the materials used. This paper addresses the analytical modeling of a unimorph piezoelectric harvester and the optimization of harvester geometry to improve the output power and resonance frequency. The harvester geometry is modeled using Finite Element Method (FEM), and the RADAR plot is used to optimize the harvester width for maximum output. The FEM-optimized model is experimentally tested with the help of a controlled vibratory system designed and developed for this purpose. The optimized model is a dumbbell-shaped harvester with 390% more open circuit output voltage and 9.6% reduced resonant frequency compared to a rectangular harvester. The maximum power of 59.9μW is harvested across 1MΩ load with a power density of 1mWcm-3 at 141Hz resonant frequency. [ABSTRACT FROM AUTHOR]

Hydrokinetic energy, a vital renewable resource, holds promise for addressing fossil fuel shortages to ensure a sustainable future. This study proposes an efficient and stable ocean wave energy harvesting system that combines a triboelectric nanogenerator (TENG), an electromagnetic generator (EMG) with a planetary gear system, and a driving turbine. The turbine transforms the up‐and‐down motion in water into continuous, unidirectional rotational motion. An EMG device accelerated by a planetary gear system further ensures sustained output at very low frequencies (0.25 Hz) and boosts the upper limit of power generation at medium to high frequencies. Under water wave conditions with a 1 Hz frequency, the TENG component yields an output of up to 2200 V and 122 µA, while the average EMG output is 15 V and 80 mA. Remarkably, the entire system maintains a steady and uninterrupted output even at extremely low frequencies (0.25 Hz). The peak power outputs for the TENG and EMG components are 115 and 350 mW, respectively, with power densities of 32.55 and 329.78 W m−3, surpassing prior achievements. This research demonstrates self‐powered applications and provides an efficient method to amplify water wave forces, enhancing energy harvesting capabilities for practical marine environmental monitoring. [ABSTRACT FROM AUTHOR]

Highlights: The flexible single-walled carbon nanotube/titanium carbide composite films exhibit excellent thermoelectric (TE), high-temperature stable and flame-retardant properties. The assembled TE device achieves an ultrafast fire warning response time of ~ 0.1 s with a threshold voltage of 1 mV. The fire warning device demonstrates exceptional repeatability and long-term stability. The designed intelligent system is promising for next-generation self-powered remote IoT fire warning applications. Fire warning is vital to human life, economy and ecology. However, the development of effective warning systems faces great challenges of fast response, adjustable threshold and remote detecting. Here, we propose an intelligent self-powered remote IoT fire warning system, by employing single-walled carbon nanotube/titanium carbide thermoelectric composite films. The flexible films, prepared by a convenient solution mixing, display p-type characteristic with excellent high-temperature stability, flame retardancy and TE (power factor of 239.7 ± 15.8 μW m−1 K−2) performances. The comprehensive morphology and structural analyses shed light on the underlying mechanisms. And the assembled TE devices (TEDs) exhibit fast fire warning with adjustable warning threshold voltages (1–10 mV). Excitingly, an ultrafast fire warning response time of ~ 0.1 s at 1 mV threshold voltage is achieved, rivaling many state-of-the-art systems. Furthermore, TE fire warning systems reveal outstanding stability after 50 repeated cycles and desired durability even undergoing 180 days of air exposure. Finally, a TED-based wireless intelligent fire warning system has been developed by coupling an amplifier, analog-to-digital converter and Bluetooth module. By combining TE characteristics, high-temperature stability and flame retardancy with wireless IoT signal transmission, TE-based hybrid system developed here is promising for next-generation self-powered remote IoT fire warning applications. [ABSTRACT FROM AUTHOR]

Lead‐free hybrid perovskites (HPs) are considered as environmentally friendly photodetection materials. However, there are few studies on self‐powered photodetection in lead‐free HPs, and most of them are achieved through the introduction of chiral ammonium cations induced bulk photovoltaic effect (BPVE). Notably, enantiomeric pure chiral ammonium cations are difficult to synthesize, the quantity is small and the price is high. Therefore, choosing achiral ammonium cations to induce BPVE in lead‐free HPs is crucial. Herein, achiral cations 1,3‐bis(aminomethyl)cyclohexane (1,3‐BMACH) is exploited to induce bulk photovoltaic through confinement effect in (1,3‐BMACH)BiI5, then self‐powered X‐ray detection is successfully realized. Due to the large space in zero‐dimensional (0 D) (MXD)BiI5 (MXD is meta‐xylylenediammonium), the confinement effect is not obvious, resulting in the disorderly arrangement of MXD2+ cations and a centrosymmetry structure of (MXD)BiI5. Benefiting from the large photovoltage (1.0 V) of (1,3‐BMACH)BiI5 under X‐ray, its single crystal devices exhibit ultra‐high sensitivity of 170 µC Gy−1 cm−2 and extremely low detection limit of 49 nGy s−1 under self‐powered mode, which almost surpassing most low‐dimensional single‐phase lead‐free HPs at 0 V bias. This work has promoted the application of lead‐free HPs in the field of self‐powered X‐ray detection. [ABSTRACT FROM AUTHOR]

Self-powered photoelectrochemical (PEC) ultraviolet photodetectors (UVPDs) are promising for next-generation energy-saving and highly integrated optoelectronic systems. Constructing a heterojunction is an effective strategy to increase the photodetection performance of PEC UVPDs because it can promote the separation and transfer of photogenerated carriers. However, both crystal defects and lattice mismatch lead to deteriorated device performance. Here, we introduce a structural regulation strategy to prepare TiO2 anatase-rutile heterophase homojunctions (A-R HHs) with oxygen vacancies (OVs) photoanodes through an in situ topological transformation of titanium metal–organic framework (Ti-MOF) by pyrolysis treatment. The cooperative interaction between A-R HHs and OVs suppresses carrier recombination and accelerates carrier transport, thereby significantly enhancing the photodetection performance of PEC UVPDs. The obtained device realizes a high on/off ratio of 10,752, a remarkable responsivity of 24.15 mA W−1, an impressive detectivity of 3.28 × 1011 Jones, and excellent cycling stability. More importantly, under 365 nm light illumination, a high-resolution image of “HUST” (the abbreviation of Harbin University of Science and Technology) was obtained perfectly, confirming the excellent optical imaging capability of the device. This research not only presents an advanced methodology for constructing TiO2 -based PEC UVPDs, but also provides strategic guidance for enhancing their performance and practical applications. [ABSTRACT FROM AUTHOR]

The photovoltaic effect and pyro‐phototronic effect offer a promising approach to enhance self‐powered photodetectors (PDs) performance. However, further investigation is warranted to explore the performance improvement, the impact of pyroelectric effect, and the underlying coupling mechanism. In this study, heterojunction PDs consisting of ITO/CH3NH3(MA)PbI3:P(VDF‐TrFE)/Si are prepared, with P(VDF‐TrFE) concentration varying from 0 to 1 wt.%. The results reveal that the concentration of P(VDF‐TrFE) has a significant impact on the photovoltaic response, with the optimal concentration being 0.8 wt.%. The PD displays a broadband response (405–1064 nm) at zero bias, peaking at 780 nm. Furthermore, the introduction of P(VDF‐TrFE) significantly enhances the responsivity (R) and detectivity (D), resulting in a remarkable increase of 5814%. The values of R and D reach 1.93 × 104 V W−1 and 1.99 × 1012 Jones, respectively. Moreover, the PD demonstrates an ultrafast response time of 81.6/208 µs. Additionally, the pyro‐phototronic effect extends the response wavelength to 1550 nm, surpassing the spectral limit of the heterojunction. Importantly, the heterojunction exhibits improved weak light detection ability. At 6.37 µW cm−2 intensity, R and D show an impressive increase of 21 683%, reaching 8.99 × 104 V W−1 and 9.3 × 1013 Jones, respectively. [ABSTRACT FROM AUTHOR]

In this study, α-Ga2O3 nanorod arrays (NRAs) were grown using a simple and low-cost two-step hydrothermal method. Subsequently, a photoelectrochemical ultraviolet photodetector (PEC-UV PD) based on the α-Ga2O3 NRAs was fabricated, which can operate at zero bias and has a performance far superior to that of PEC-UV PDs based on the one-step hydrothermal method. Under 2 mW/cm2 illumination at 254 nm, the device achieved a responsivity of 26.59 mA/W, an external quantum efficiency of 12.98%, and a rise/decay time of 53 ms/7 ms without external bias. These results demonstrate outstanding detection performance compared to previously reported devices. The superior performance can be attributed to the better crystallinity which provides a larger absorption area for the device, the solution contact area, and a faster channel for carrier transport, the space charge region at the solid/liquid interface which also allows efficient separation of photogenerated carriers. Furthermore, it also benefits from the positive effects of moderate oxygen vacancy (VO) concentrations for NRAs. The α-Ga2O3 NRAs PEC-UV PD with two-step hydrothermal method is undoubtedly a promising candidate for future solar-blind detection. [ABSTRACT FROM AUTHOR]

Self-powered photoelectrochemical (PEC) ultraviolet photodetectors (UVPDs) are promising for next-generation energy-saving and highly integrated optoelectronic systems. Constructing a heterojunction is an effective strategy to increase the photodetection performance of PEC UVPDs because it can promote the separation and transfer of photogenerated carriers. However, both crystal defects and lattice mismatch lead to deteriorated device performance. Here, we introduce a structural regulation strategy to prepare TiO2 anatase-rutile heterophase homojunctions (A-R HHs) with oxygen vacancies (OVs) photoanodes through an in situ topological transformation of titanium metal–organic framework (Ti-MOF) by pyrolysis treatment. The cooperative interaction between A-R HHs and OVs suppresses carrier recombination and accelerates carrier transport, thereby significantly enhancing the photodetection performance of PEC UVPDs. The obtained device realizes a high on/off ratio of 10,752, a remarkable responsivity of 24.15 mA W−1, an impressive detectivity of 3.28 × 1011 Jones, and excellent cycling stability. More importantly, under 365 nm light illumination, a high-resolution image of “HUST” (the abbreviation of Harbin University of Science and Technology) was obtained perfectly, confirming the excellent optical imaging capability of the device. This research not only presents an advanced methodology for constructing TiO2 -based PEC UVPDs, but also provides strategic guidance for enhancing their performance and practical applications. [ABSTRACT FROM AUTHOR]

Highlights The flexible single-walled carbon nanotube/titanium carbide composite films exhibit excellent thermoelectric (TE), high-temperature stable and flame-retardant properties. The assembled TE device achieves an ultrafast fire warning response time of ~ 0.1 s with a threshold voltage of 1 mV. The fire warning device demonstrates exceptional repeatability and long-term stability. The designed intelligent system is promising for next-generation self-powered remote IoT fire warning applications.

Heterojunctions formed between undoped and Eu‐doped NiO nanofibers (NFs) and n‐Si were fabricated by electrospinning the NiO:Eu NFs onto Si. Since the photoresponse of the Eu‐doped NiO‐containing device was better than the undoped one, the study focused on the doped NiO‐containing device. This was explained by the increase in electron kinetics in terms of the active role of Eu in bonding with the 4f orbitals and the s, d, and f states of NiO. Electro‐optical measurements of the NiO:Eu NFs/n‐Si heterojunction were performed in the visible region depending on the light intensity and in the UV and NIR regions for 10 mW/cm2 powers. It was observed that the device exhibits a good level of rectification properties and responds very well to all lights. At all three light sources, the heterojunction photodetector exhibited self‐powered behavior. Furthermore, for 10 mW/cm2 light intensity, the NiO:Eu NFs/n‐Si photodetector achieved R values of 1.84 A/W at 365 nm, 0.98 A/W at 395 nm, and 1.54 A/W at 850 nm, while it is 0.12 A/W for visible light. Besides, the device showed an external quantum efficiency of 625% and this was attributed to the photocurrent gain. In self‐driven mode, D* values have been determined as 3.0 × 1012 Jones, 2.6 × 1012 Jones, and 2.9 × 1012 Jones for 365, 395, and 850 nm, respectively. The performance of NiO under UV light was attributed to the absorption of NiO under UV light, as well as the very good excitation of (Eu3+) ions by UV light. [ABSTRACT FROM AUTHOR]

An efficient room-temperature self-powered, broadband (300 ​nm–1100 nm) photodetector based on a CuO–TiO2/TiO2/p-Si(100) heterostructure is demonstrated. The CuO–TiO2 nanocomposites were grown in a two-zone horizontal tube furnace on a 40 ​nm TiO2 thin film deposited on a p-type Si(100) substrate. The CuO–TiO2/TiO2/p-Si(100) devices exhibited excellent rectification characteristics under dark and individual photo-illumination conditions. The devices showed remarkable photo-response under broadband (300–1100 ​nm) light illumination at zero bias voltage, indicating the achievement of highly sensitive self-powered photodetectors at visible and near-infrared light illuminations. The maximum response of the devices is observed at 300 ​nm for an illumination power of 10 ​W. The response and recovery times were calculated as 86 ​ms and 78 ​ms, respectively. Moreover, under a small bias, the devices showed a prompt binary response by altering the current from positive to negative under illumination conditions. The main reason behind this binary response is the low turn-on voltage and photovoltaic characteristics of the devices. Under illumination conditions, the generation of photocurrent is due to the separation of photogenerated electron-hole pairs within the built-in electric field at the CuO–TiO2/TiO2 interface. These characteristics make the CuO–TiO2/TiO2 broadband photodetectors suitable for applications that require high response speeds and self-sufficient functionality.

Conventional research on linear polarization photodetector for 2D materials has focused on the search for different anisotropic materials, combinations between materials, introducing plasmonic structures, and patterning 2D materials to improve performance. However, these methods provide limited improvement in polarization sensitivity. Here, a balanced photodetector structure is proposed that does not require an additional process and relies only on the presence of anisotropy in the material itself to substantially improve the polarization sensitivity. The balanced photodetector consists of two ReS2 photodetectors, where the single ReS2 photodetector exhibits excellent performance at 650 nm illumination, including a responsivity and detectivity of 0.28 A W−1 and 4.22 × 109 Jones. Benefiting from the anisotropy of ReS2, the single photodetector achieves excellent polarization sensitivity of 2.79 at 650 nm. The balanced photodetector system achieves an excellent performance of ≈20 dB linear polarization extinction ratio and 0.003° Hz−1/2 noise equivalent light polarization difference at 100 kHz. These performances can also be further optimized by adjusting the gate voltage. The results provide a basis for further development of high‐performance polarization photodetector for 2D materials. [ABSTRACT FROM AUTHOR]

The development of flexible electronics for detecting solar‐blind deep ultraviolet (UV‐C) light holds great promise for emerging technologies. Here, flexible photoelectrochemical photodetectors (PEC‐PDs) are demonstrated for self‐powered solar‐blind UV‐C sensing based on one‐step radio frequency sputtered amorphous gallium oxide (a‐Ga2O3) thin films on indium tin oxide‐coated polyethylene naphthalate (ITO/PEN) substrates in a simple and low‐cost manner. Surface functionalization of the ITO/PEN substrates with silver nanowires (Ag NWs) successfully embedded within the a‐Ga2O3 films significantly enhances the optoelectronic performance. Incorporating Ag NWs reduces charge transfer resistance and potential barrier, while enhancing built‐in electric field at the Ag NWs/a‐Ga2O3 interface, synergistically facilitating efficient electron transport. Consequently, the Ag NW‐modified PEC‐PDs exhibit approximately two‐fold increases in key metrics including responsivity (11.23 mA W−1) and response times (0.07/0.09 s rise/decay) under 254 nm illumination compared to pristine devices. Moreover, the Ag NW‐functionalized PEC‐PDs demonstrate superb mechanical flexibility and fatigue durability, maintaining ≈95% of the initial photoresponse current and responsivity after 500 bending cycles. This work provides valuable insights into designing high‐performance flexible self‐powered PEC‐PDs through ingenious photoanode engineering. [ABSTRACT FROM AUTHOR]

Self‐powered near‐infrared (NIR) photodetectors utilizing low‐dimensional materials are promising owing to their low‐power‐consumption and superior photoresponse performance. The strong light‐matter interaction and other intriguing physical mechanisms (such as high mobility, dangling‐bond‐free surface) in 2D semiconductor materials, combined with the flexible fabrication of device structures, create new opportunities for the optoelectronic devices. Here, a self‐powered NIR Schottky junction photodetector is demonstrated by vertically stacking 2D PtSe2 film atop an InP wafer. The strong built‐in electric field formed at PtSe2/InP interface endows the device with self‐powered operation with an ultralow dark current of 45 pA at room temperature under 0 V bias. The responsivity and detectivity at 940 nm illumination reach up to 0.718 A W−1 and 4.37 × 1012 Jones, respectively. Furthermore, TCAD simulations showed that the significant electric field at the PtSe2/InP interface is pivotal for its superior self‐powered detection performance. Remarkably, the device achieves a high Ilight/Idark ratio exceeding 105 and a fast response time of 4.35/5.66 µs, and sensitivity to NIR light polarization. This study provides a new perspective for the integration of hybrid 2D materials with 3D semiconductors in the next‐generation optoelectronic devices and integrated systems. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) photodetectors have attracted extensive attention in various applications, including aerospace, optical communication, and fire warning. However, the intrinsic coupling of high responsivity and fast response as well as imperfect interface transmission impede the further improvement of UV photodetector. Here, a high‐performance Au‐decorated PbI2/ZnO pn junction UV photodetector with a one‐dimensional (1D) and two‐dimensional (2D) interspersed structure is presented. The pyro‐phototronic effect and energy band engineering effect from the localized pn junction generated by the layered p‐type PbI2 nanosheets along the c‐axis of ZnO are coupled to modulate the separation and transport of photogenerated carriers. Furthermore, the localized surface plasmon resonance of Au nanoparticles produces transient thermal power to raise temperature fast to enhance pyroelectric current. The self‐powered Au@PbI2/ZnO photodetector displays a high responsivity of 0.21 A W−1, excellent detectivity of 7.9 × 1012 Jones, and fast response/recovery time of 25/31 ms, under the illumination of 325 nm light with the power density of 0.08 µW cm−2. This work offers an effective strategy for designing high‐performance next‐generation optoelectronic devices. [ABSTRACT FROM AUTHOR]

Achieving highly efficient self‐powered fibrous sensing systems is desirable for smart electronic textiles but remains a great challenge. Here, a bifunctional hydrogel is proposed by introducing of polyacrylic acid grafted MXene (MXene‐g‐PAA) into polyacrylamide/chitosan, achieving high‐sensitivity sensor and a stable hydrogel electrolyte of battery. The MXene‐g‐PAA flakes act as ion transport "highway", significantly enhance ionic conductivity, thereby increasing the sensitivity of sensors and facilitating Zn2+ diffusion in Zn‐ion battery (ZIB). The rich hydrogen bonding network in the hydrogel improves its mechanical properties and limits water molecule movement, thus reducing side reactions and prolonging the stability of ZIB. As a result, the fibrous sensor exhibits high strain sensitivity (gauge factor of 2.4) with a wide detection range (0–800%), and the fibrous Zn‐ion battery exhibits high capacity (353 mAh cm−3) with long cycling stability (400 cycles). The hydrogel‐based sensor and ZIB can be easily integrated into a flexible self‐powered sensing system, which effectively detects human movement and 3D ball motion. The bifunctional hydrogel with the integrated fibrous system will shed light on the development of next‐generation smart electronic textiles. [ABSTRACT FROM AUTHOR]

Multi‐dimensional force sensing that combines intensity, location, area and the like could gather a wealth of information from mechanical stimuli. Developing materials with force‐induced optical and electrical dual responses would provide unique opportunities to multi‐dimensional force sensing, with electrical signals quantifying the force amplitude and the luminescence output providing spatial distribution of force. However, the reliance on external power supply and high‐energy excitation source brings significant challenges to the applicability of multi‐dimensional force sensors. Here we reported the mechanical energy‐driven and sunlight‐activated materials with force‐induced dual responses, and investigated the underlying mechanisms of self‐sustainable force sensing. Theoretical analysis and experimental data unraveled that trap‐controlled luminescence and interfacial electron transfer play a major role in force‐induced optical and electrical output. These materials were manufactured into pressure sensor with renewable dual‐mode output for quantifying and visualization of pressures by electrical and optical output, respectively, without power supply and high‐energy irradiation. The quantification of tactile sensation and stimuli localization of mice highlighted the multi‐dimensional sensing ability of the sensor. Overall, this self‐powered pressure sensor with multimodal output provides more modalities of force sensing, poised to change the way that intelligent devices sense with the world. [ABSTRACT FROM AUTHOR]

The rapid growth of global energy consumption and the increasing demand for sustainable and renewable energy sources have urged vast research into harnessing energy from various sources. Among them, the most promising approaches are nanogenerators (NGs) and solar cells (SCs), which independently offer innovative solutions for energy harvesting. This review paper presents a comprehensive analysis of the integration of NGs and SCs, exploring advanced hybrid structures and their diverse applications. First, an overview of the principles and working mechanisms of NGs and SCs is provided for seamless hybrid integrations. Then, various design strategies are discussed, such as piezoelectric and triboelectric NGs with different types of SCs. Finally, a wide range of applications are explored that benefit from the synergistic integration of NGs and SCs, including self‐powered electronics, wearable devices, environmental monitoring, and wireless sensor networks. The potential for these hybrid systems is highlighted to address real‐world energy needs and contribute to developing sustainable and self‐sufficient technologies. In conclusion, this review provides valuable insights into the state‐of‐the‐art developments in NGs and SCs integration, shedding light on advanced hybrid structures and their diverse applications. [ABSTRACT FROM AUTHOR]

In recent years, 2D materials and their heterostructures have started to offer an ideal platform for high-performance photodetection devices. In this work, a highly responsive, self-powered photodetector based on PtSe2/MoS2 van der Waals heterostructure is demonstrated. The device achieves a noteworthy wide band spectral response from visible (405 nm) range to the near infrared region (980 nm). The remarkable photoresponsivity and external quantum efficiency up to 4.52 A/W, and 1880% are achieved, respectively, at 405 nm illumination with fast response time of 20 ms. In addition, the photodetector exhibits a decent photoresponsivity of 33.4 mA/W at zero bias, revealing the photodetector works well in the self-driven mode. Our work suggests that a PtSe2/MoS2 heterostructure could be a potential candidate for the high-performance photodetection applications. [ABSTRACT FROM AUTHOR]

Herein, the Polyvinyl pyrrolidone (PVP)‐assisted CdS/PbI2 heterojunction UV–visible photodetector is constructed by the sol–gel spin coating method. The X‐ray diffraction, scanning electron microscopy, and energy dispersive spectrometer demonstrate the synthesis and successful complexation of PVP, CdS, and PbI2. The UV–visible absorption spectroscopy and UV photoelectron spectroscopy measurements of CdS and PbI2 are carried out to prove that the CdS and PbI2 form a type II heterojunction. Compared with pure CdS film photodetector, the CdS (PVP)/PbI2 heterojunction photodetector has self‐powered characteristics, and exhibits excellent photoconductivity in the UV–visible with higher switching ratios, detection rates, and faster response times of 1.1 × 105, 9.77 × 1011 Jones, and 20 ms, respectively, which has great potential in the field of UV–visible self‐powered photodetector. [ABSTRACT FROM AUTHOR]

The consumption of high power and an extended start-up time are some of the major issues faced by piezoelectric energy harvesting. With this in mind, a control circuit with an extremely low power consumption of a few milliwatts is designed in this paper to energize heavy loads like wireless sensor nodes. A low-duty cycled self-powered control circuit, which works only at the maximum power point, is proposed in this paper. During a cold-start, optimum operative conditions can be achieved by this circuit. Moreover, a low power threshold at the input is sufficient to start the circuit. An additional piezoelectric transducer or a DC power supply is not required to operate this designed circuit. In terms of harvesting energy, performance enhanced by 320% can be achieved by this circuit when compared to the standard energy harvesting circuit when connected to a series-synchronized switch harvesting on an inductor (SSHI) with a large storage capacitor of 150 mF. An input power of 4.42 μW is enough for the circuit during cold-start and it consumes an ultra-low power of 0.3 μW. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENG) have emerged as a highly promising energy harvesting technology, attracting significant attention in recent years for their broad applications. Gel-based TENGs, with superior stretchability and sensitivity, have been widely reported as wearable sensors. However, the traditional hydrogel-based TENGs suffer from freezing at low temperatures and drying at high temperatures, resulting in malfunctions. In this study, we introduce an anti-freezing eutectogel, which uses a deep eutectic solvent (DES), to improve the stability and electrical conductivity of TENGs in harsh environmental conditions. The eutectogel-based TENG (E-TENG) produces an open-circuit voltage of 776 V, a short-circuit current of 1.54 µA, and a maximum peak power of 1.1 mW. Moreover, the E-TENG exhibits exceptional mechanical properties with an elongation at a break of 476% under tension. Importantly, it maintains impressive performances across a wide temperature range from −18 to 60 °C, with conductivities of 2.15 S/m at −10 °C and 1.75 S/m at −18 °C. Based on the excellent weight stability of the E-TENG sensor, motion sensing can be achieved in the air, and even underwater. Finally, the versatility of the E-TENG can serve as a wearable sensor, by integrating it with Bluetooth technology. The self-powered E-TENG can monitor various human motion signals in realtime and send the health signals directly to mobile phones. This research paves a new road for the applications of TENGs in harsh environments, offering wireless flexible sensors with real-time health signal monitoring capabilities. [ABSTRACT FROM AUTHOR]

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Triboelectric nanogenerator (TENG) is a promising technology, which can convert biokinetic energy into electricity and be utilized as self‐powered sensors and power sources for wearable electronics. The existing designs of conventional TENGs require complex fabrication processes and device structures, and they need to be attached on human body for wearable application, which is uncomfortable and may lead to malfunction under intense body moment. Here, a direct current TENG is proposed by utilizing natural human body, basketball, shoes, and ground floor. A unidirectional peak voltage and current output up to 700 V and 23 µA can be generated when a player plays a basketball, which can lighten up an array of 240 LEDs, and charge a 100 µF capacitor to 3.2 V in 1 min. The output of TENG is utilized to identify different movements of a basketball player using machine learning algorithm with an accuracy up to 96.7%. Moreover, the human body enabled direct current TENG (HBDC‐TENG) is used as a self‐powered sensor and an energy harvester for a wireless sensing system, which can collect human motion and environmental information, and transmit them wirelessly. The HBDC‐TENG has a great significance for self‐powered wearable electronics, providing a viable solution for human motion status and ambient environment monitoring. [ABSTRACT FROM AUTHOR]

Wearable devices, interactive human-machine interface equipment, wireless sensors, and small-scale cleaning devices play crucial roles in biomedical implantation, disease treatment, health monitoring, environmental purification, etc. These devices require a sustainable energy source to work effectively. With the consideration of the global energy crisis and environmental pollution, researchers are exploring new, stable, and environmentally friendly methods to power these low-powered devices. Mechanical energy is one of the most abundant natural energy sources. Converting mechanical energy from the ambient environment or host structures into electrical energy via the direct piezoelectric effect is an efficient energy harvesting technique. This paper reviews the application of advanced piezoelectric materials, and small-scale self-powered and self-sensing piezoelectric devices at the cubic centimeter scale in energy harvesting and health monitoring of human, animal, machinery, roads, bridges, as well as the pollutant degradation of the environment. Some of these devices have the capability to not only harvest mechanical energy but also enable real-time monitoring and analysis of the electrical signals generated by the direct piezoelectric effect, facilitating prompt decision-making and appropriate responses. In addition, potential challenges and future prospects of small-scale self-powered and self-sensing piezoelectric devices are discussed. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have aroused worldwide efforts for developing optoelectronic devices due to their unique optical properties and low‐cost simple fabrication process. In recent years, various perovskites‐based miniaturized optical devices have been actively investigated due to their record‐breaking efficiency in different fields, including environmental monitoring, remote sensing, biomedical imaging, and optical communications. In this review, a succinct and critical survey of recently discovered organic–inorganic perovskite photodetectors providing insights into their structural properties and key performance parameters is staged. First, key features of perovskites‐based photodetectors emphasizing their optoelectronic and electrical properties are introduced. Then, the polarization‐sensitive detection of metal halide perovskites using polarization‐selective optical structures is discussed. The bandgap engineering for tailoring the properties of perovskite photodetectors by changing the chemical composition and material structures is also highlighted in this report. Finally, a perspective on future opportunities and current challenges for designing perovskite‐based optoelectronic devices is presented. [ABSTRACT FROM AUTHOR]

In the search for new advanced 2D materials for technological applications and to expand the research of non‐van der Waals (non‐vdW) 2D electronic devices, this study presents a novel strategy for liquid phase exfoliation (LPE) of non‐vdW Cr2S3 to produce Cr2S3 nanosheets (NSs). By utilizing N‐methyl‐2‐pyrrolidone (NMP), bulk Cr2S3 is separated along the (001) plane, resulting in the formation of NSs with an average thickness of ≈3 nm. Various characterization techniques are applied to the Cr2S3 material before and after LPE. Subsequently, the obtained Cr2S3 NSs are integrated into a photoelectrochemical (PEC)‐type photodetector (PD) to evaluate the photoelectric conversion efficiency under varying conditions. The findings indicate that the developed PD exhibits a distinct self‐powered photodetection capability with a photocurrent (Pph) of 39.5 nA cm−2, a photoresponsivity (Rph) of 622 nA W−1, and a detectivity (D*) of 0.5 × 107 Jones under 350 nm irradiation at 0 V. Moreover, the PD demonstrates rapid response time (0.06 s) and good long‐term stability (over 15 days), thus providing valuable insight for the advancement of non‐vdW Cr2S3‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Self‐powered electronic skins (e‐skins), as on‐skin human‐machine interfaces, play a significant role in cyber security and personal electronics. However, current self‐powered e‐skins are primarily constrained by complex fabricating process, intrinsic stiffness, signal distortion under deformation, and inadequate comprehensive performance, thereby hindering their practical applications. Herein, a novel highly stretchable (534.5%), ionic conductive (4.54 S m−1), thermogalvanic (1.82 mV K−1) hydrogel (TGH) is facilely fabricated by a one‐pot method. Owing to the formation of Li+(H2O)n hydration structure, the TGH presents excellent anti‐freezing and non‐drying performance. It remains flexible and conductive (3.86 S m−1) at −20 °C and shows no obvious degradation in the thermoelectrical performance over 10 days. Besides, acting as a self‐powered e‐skin, the TGH combined with deep learning technology for signature recognition and biometric authentication is successfully demonstrated, achieving an accuracy of 92.97%. This work exhibits the TGH‐based e‐skin's tremendous potential in the new generation of human‐computer interaction and information security. [ABSTRACT FROM AUTHOR]

In the swiftly progressing landscape of wearable electronics and the Internet of Things (IoTs), there is a burgeoning demand for devices that are lightweight, cost‐effective, and self‐powered. In this study, a self‐powered bidirectional knee joint motion monitoring system is introduced, leveraging a dual ratchet sensing (DRS) system fabricated using 3D printing technology. This approach offers substantial economic and portability benefits. The DRS system is engineered to harness the negative work generated from knee joint movements to power commercial electronic devices, obviating the need for additional metabolic energy from the human body. By synergizing the DRS with virtual reality technology, it becomes feasible to monitor knee joint movements in real‐time with remarkable accuracy, presenting a novel avenue for the integration of digital twin technology. Through the amalgamation of convolutional neural network machine learning algorithms with Bayesian optimization techniques, the DRS system can discern up to 97% of knee joint movements, paving the way for innovative applications in smart rehabilitation and healthcare. [ABSTRACT FROM AUTHOR]

[Display omitted] Convenient, small-sized, and self-powered sensor units are easier to integrate, making them the future development direction of photodetectors. GaN materials with wide band gap are powerful candidates for UV detection, but most GaN based self-powered UV photodetectors have poor detection ability for the weak UV light, which limits their applications. This study reports a self-powered UV photodetector based on BaTiO 3 /GaN heterojunction, which can detect ultra-weak UV light at a minimum of 0.68 nW/cm2 by coupling the ferroelectric polarization, anti-reflection effect, and pyro-phototronic effect. The polarized BaTiO 3 thin film on the surface of GaN has an enhanced residual polarization field and generated anti-reflection effect, which can regulate the heterojunction band structure, suppress the dark current and minimize surface reflection of GaN. Simultaneously enhanced pyro-phototronic effect can significantly improve the response speed and responsivity of the device. The response time and recovery time of the device are as low as 8.794 ms and 5.018 ms. The maximum responsivity and detectivity are 88.206 mA/W and 7.392 × 1013 Jones, respectively, increased by 359% and 6065% compared to the device before polarization. Thanks to excellent material stability, the device has a sensitive and uniform response to continuously incident UV light. In addition, by simulating flame generation, it has been proven that the device has brilliant performance in flame detection and can achieve remote monitoring and fire warning functions. These results can promote the potential application of self-powered UV photodetectors based on BaTiO 3 /GaN heterojunction in environmental monitoring and space communication fields. [ABSTRACT FROM AUTHOR]