Antimony sulfide (Sb2S3) is a promising, environmentally friendly semiconductor for novel photodetectors in view of its superior optoelectronic properties. In particular, Sb2S3 has a quasi-one-dimensional (Q1D) crystallographic structure, which enables efficient charge-carrier transport for photodetectors if the film orientation can be well-controlled. In this work, high-performance Sb2S3 photodetectors are developed through crystallographic orientation engineering. Hydrothermal deposition processed [hk0]-oriented Sb2S3 films and close-spaced sublimation processed [hk1]-oriented Sb2S3 films were successfully designed to construct photoconductive and photovoltaic Sb2S3 devices, respectively. The careful studies reveal the correlation between the film orientation and device performance. The photoconductive detectors based on [hk0]-oriented films achieve enhanced responsivity of 2.032 A W-1 and detectivity of 2.24 × 1013 Jones in view of favorable horizontal charge-carrier transport. The photovoltaic detectors based on [hk1]-oriented films deliver improved responsivity of 8.35 × 10-2 A W-1 and detectivity of 4.15 × 1012 Jones through efficient vertical charge-carrier transport. This work provides more insights into the dependence of the optoelectronic properties of Sb2S3 devices on the crystal orientation, proving that tailoring preferential crystal orientations through deposition strategies is an effective approach to achieving high-performance photodetectors.

ABSTRACT Motion recognition and image preprocessing are critical for artificial vision systems, but there remains a need for more efficient and energy‐saving devices with versatile image processing capabilities. Herein, we developed highly efficient photovoltaic detectors with bidirectional photocurrent and polarization‐sensitive characteristics by sandwiching gold nanoparticles (Au NPs) between MoTe 2 and ReS 2 , enabling two photoelectric units to operate collaboratively. The Au NPs induce localized surface plasmon resonance (LSPR) and hot electron injection, modulating the interface electronic structure, enhancing the light absorption efficiency, and extending the spectral response range to 1550 nm, surpassing the bandgap limitations of MoTe 2 and ReS 2 . The responsivity and detectivity reach up to 8.35 A W −1 and 9.6 × 10 11 Jones under 808 nm, respectively, which are about two orders of magnitude improvement over the pristine MoTe 2 /ReS 2 device. The polarization ratio (PR) also increases from 4.7 to 9.1, which enables multi‐task image processing applications. Leveraging the bidirectional photocurrent and polarization photo‐response, the convolution processing is further combined with the device for realizing motion recognition and image processing tasks, including sharpening, edge extraction, and noise filtering. This work opens a new avenue for the development of Au NPs engineered photodetectors for image processing and motion recognition applications.

The accumulation of toxic metal ions from industrial activities poses significant environmental and health risks, thus necessitating the development of portable, rapid, and highly sensitive detection systems. We report a self-powered photovoltaic colorimetric sensor that is capable of detecting Al 3+ , Fe 3+ , and Cu 2+ ions at nanomolar concentrations. Traditional spectrometer-based platforms are bulky and unsuitable for onsite applications, whereas conventional colorimetric sensors often suffer from limited sensitivity and poor reproducibility. To address these limitations, we utilize a rhodamine derivative (R6GH) that undergoes a ring-opening reaction upon interaction with target metal ions, which results in a visible color change under green LED illumination. The portable sensor integrates a Schottky junction that is fabricated by depositing gallium-doped zinc oxide (GZO) onto an n-type silicon substrate via atomic layer deposition, which enables the efficient conversion of optical signals into electrical outputs. The device operates in dual detection mode. In voltage mode, the detection limits are 16 nM for Al 3+ , 22 nM for Fe 3+ , and 41 nM for Cu 2+ . In current mode, the respective detection limits are 26, 18, and 34 nM. Compared with conventional chemosensors, this system offers an improvement in sensitivity of up to two orders of magnitude. Additionally, the sensor demonstrates excellent signal reproducibility, with a relative standard deviation (RSD) of less than 1.14 % across 560 switching cycles. The combination of high sensitivity, rapid response (<30 s), and stable, self-powered operation makes this device a promising candidate for real-time metal ion monitoring for the future of bioelectronic devices in healthcare. • A self-powered photovoltaic colorimetric sensor that is aligned with power-saving goals is developed. • Determination of Al 3+ , Fe 3+ , and Cu 2+ ions at nanomolar concentrations is achieved. • The portable sensor demonstrates a Schottky junction via atomic layer deposition. • The sensor exhibits high sensitivity, a rapid response (<30 s), and stable operation.

Photovoltaic solar-blind ultraviolet photodetectors (SBPDs) operate independently of an external power source, addressing critical demands in extreme environments, such as forest fire detection and atmospheric ozone layer monitoring. Gallium oxide (Ga2O3) offers significant potential for extreme applications due to its radiation resistance and high-temperature stability. Here, we present a novel homoepitaxy strategy to produce an "atomic smooth" step-flow Ga2O3 photosensitive layer, successfully fabricating device-grade Ga2O3/n+-Ga2O3 homojunctions for photovoltaic SBPDs. These devices exhibit a maximum open-circuit voltage of 1.0 V, an ultrahigh external quantum efficiency of 59.5%, and an ultrafast response time of 100 ns under zero bias, maintaining consistent performance even at 390 K. By implementing a 2D step-flow growth mode, both bulk and interface defects were effectively suppressed, achieving the desired band alignment. Furthermore, the optimized high-quality depletion region formed by the Ga2O3 layer facilitates enhanced carrier drift, resulting in an efficient carrier collection. This work fully explores the potential of Ga2O3 SBPDs for extreme applications and provides an effective design strategy for achieving photovoltaic detectors characterized by zero power consumption, high responsivity, and rapid response.

The development of efficient and economic ultraviolet (UV) photodetectors is urgently required for many military and civil utilizations. Herein, we report on a UV photovoltaic-type detector utilizing a two-dimensional wide bandgap PEA2PbBr4 perovskite as the light-absorbing media. By introducing a MoO3 thin layer to enhance hole transport and extraction, the photovoltage/photocurrent of the detector is improved, and the dark current is depressed simultaneously, rendering a significantly enhanced UV photoresponse. Remarkably, a UV self-driven detector constructed on a rigid substrate attains a high photovoltage responsivity of 6.58 × 105 V/W, a large photocurrent responsivity of 182.3 mA/W, a respectable specific detectivity of 1.1 × 1012 Jones, a rapid response speed of 16.2/26.2 ms, and a sizable linear dynamic range of 134 dB, upon 365 nm UV irradiation, along with a large UV/visible rejection ratio of 1047. Also, the above photoresponse parameters can reach 2.61 × 105 V/W, 90.1 mA/W, 1.57 × 1011 Jones, 17.4/27.5 ms, 119 dB, and 1021, for a device assembled on a plastic substrate. More importantly, both detectors exhibit ultralow dark currents on the order of pA, endowing them with the capability of sensing ultraweak UV light signals as low as 4.1 nW/cm2. Plus, the flexible UV detector exhibited robust mechanical flexibility and bending durability. The utilization as a UV image sensor is demonstrated, as well. These UV photodetectors may find potential utilization in future UV optoelectronic systems.

In this study, electrospun polyvinylpyrrolidone (PVP) nanofibers of varying Zn:Sn metal ion ratios were fabricated for optoelectronic applications. FESEM revealed reduced fiber diameter and connectivity when the Zn:Sn mixing ratio was increased. FTIR spectra exhibited characteristic PVP bands with slight shifts and intensity variations, along with the appearance of metal-oxygen bands. The thermal analysis indicates increasing the thermal stability with the added ions. Photovoltaic measurements showed that the Zn:Snmixed PVP fibres/n-type silicon exhibited a photovoltaic behavior, of 0.42% efficiency at a Zn:Sn ratio of 3:7. These results indicate the enhancement of co-ions-mixed PVP fibers for photovoltaic detectors.

Multi-messenger astronomy and time-domain astronomy are strongly linked even if they do not have the same objectives. Multi-messenger astronomy is an astrophysical observation approach born by the simultaneous, even if casual, detection of a few events discovered up to now. In contrast, time-domain astronomy is a recent technological trend that aims to make observations to explore the sky not with imaging, astrometry, photometry or spectroscopy but through the fast dynamic behavior of celestial objects. Time-domain astronomy aims to detect events on a temporal scale between seconds and nanoseconds. In this paper, a time-domain infrared fast detector for ground-based telescopes is proposed. This instrument can be useful for multi-messenger observations, and it is able to detect fast astronomical signals in the order of 1 ns. It is based on HgCdTe photoconductors, but the InAsSb photovoltaic detector has also been tested. The detection system designed to detect fast mid-infrared bursts includes trigger modules, an off-line noise-canceling strategy, and a classifier of the transients. Classification is derived from the analysis of fast instabilities in particle circular accelerators. This paper aims to be a preliminary feasibility study.

Carrier dynamics analysis of self-powered Sb2Se3 heterojunction photovoltaic detectors with a broad spectral response

This research include the designation of newly instrument (Turbidmeter) depending on using photo voltaic detector (8.5mm.*8.5mm.).These dimensions have large area which increases the scattering rays with a variable intensity. The properties of this design are local mode and the used tools are a available in the local markets as well as its less cost light weight system. It is worth mentioning that the possibility of its application in many fields such as: Clinical, Laboratory, Industrial and Fuel fields. This designation, applied to estimate Barium Sulphate in turbidity method. The analytical results show high accuracy and repetition, also the linearity ranges from (4-180) ppm. At the detection limit (0.05) ppm. With correlation coefficient (0.9992), as well as using volume ratio percents (ethanol-glycerin) equal to (10-90) %.

Cadmium sulfide is a valuable material for solar cells, photovoltaic, and radiation detectors. It is thus important to evaluate the material damage mechanisms and damage threshold in response to irradiation. Here, we simulate the ultrafast XUV/X-ray irradiation of CdS with the combined model, XTANT-3. It accounts for nonequilibrium electronic and atomic dynamics, nonadiabatic coupling between the two systems, nonthermal melting and bond breaking due to electronic excitation. We find that the two phases of CdS, zinc blende and wurtzite, demonstrate very close damage threshold dose of ∼0.4-0.5 eV per atom. The damage is mainly thermal, whereas with increase of the dose, nonthermal effects begin to dominate leading to nonthermal melting. The transient disordered state is a high-density liquid, which may be semiconducting or metallic depending on the dose. Later recrystallization may recover the material back to the crystalline phase, or at high doses create an amorphous phase with variable bandgap. The revealed effects may potentially allow for controllable tuning of the band gap via laser irradiation of CdS.

Lutetium oxide (Lu2O3), an ultrawide bandgap (UWB) (5.5–6.2 eV) rare-Earth oxide, has been proposed as a potential material for constructing vacuum-ultraviolet (VUV) photodetectors. In this work, an ultrathin (4 nm) aluminum oxide (Al2O3) layer is deposited at the interface of Lu2O3/GaN heterojunction to fabricate a Lu2O3 VUV photovoltaic detector with high performance. At 0 V bias and under VUV illumination, the Lu2O3/Al2O3/GaN photodetector presents a photoresponsivity of 17.2 mA/W (at 192 nm), a decay time of 54.9 ms, and a detectivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.2\times 10^{{12}}$ </tex-math></inline-formula> Jones. The excellent performance of the device comes from the ultrathin Al2O3 layer deposited at the heterojunction interface, which not only acts as a buffer layer but also as a hole-blocking layer, improving the quality of the photosensitive layer and the separation efficiency of photo-generated carriers. Furthermore, with an increase in the thickness of the Al2O3 layer (>4 nm), a deterioration of optoelectronic properties of the Lu2O3/Al2O3/GaN device can be observed, which is attributed to an increase in the transport distance of the photo-generated carrier and a reduction in the probability of electron tunneling. This work can provide a reference for the preparation of high-performance Lu2O3-based VUV photovoltaic detectors in the future.

Broad band photodetectors are found to be the inevitable component both in scientific and industrial fields. Here, PbSe colloidal QDs prepared by a simple, inexpensive hot injection method were used to fabricate ultra-broadband photodetectors with visible to near-infrared sensing capabilities. The as-fabricated photodetector has a wide spectral response and a stable photoelectric response to lasers with wavelengths ranging from 405 nm to 1550 nm. The responsivity of the photovoltaic detector is 1.43 mA W-1 at 405 nm, 4.67 mA W-1 at 980 nm and 0.2 mA W-1 at 1550 nm. The device with the optimized structure provides the maximum V oc of 250 mV under 780 nm light illumination and 100 mV even under 1550 nm illumination. Specifically, the detectivity value reaches up to 4.54 × 109 Jones under 1550 nm laser illumination with an intensity of 0.41 mW cm-2. As a result, the current study's findings serve as the foundation for the creation of a broad band photodetector that can detect light in the visible to near infrared range.

Photovoltaic panel defect detection presents significant challenges due to the wide range of defect scales, diverse defect types, and severe background interference, often leading to a high rate of false positives and missed detections. To address these challenges, this paper proposes the LEM-Detector, an efficient end-to-end photovoltaic panel defect detector based on the transformer architecture. To address the low detection accuracy for Crack and Star crack defects and the imbalanced dataset, a novel data augmentation method, the Linear Feature Augmentation (LFA) module, specifically designed for linear features, is introduced. LFA effectively improves model training performance and robustness. Furthermore, the Efficient Feature Enhancement Module (EFEM) is presented to enhance the receptive field, suppress redundant information, and emphasize meaningful features. To handle defects of varying scales, complementary semantic information from different feature layers is leveraged for enhanced feature fusion. A Multi-Scale Multi-Feature Pyramid Network (MMFPN) is employed to selectively aggregate boundary and category information, thereby improving the accuracy of multi-scale target recognition. Experimental results on a large-scale photovoltaic panel dataset demonstrate that the LEM-Detector achieves a detection accuracy of 94.7% for multi-scale defects, outperforming several state-of-the-art methods. This approach effectively addresses the challenges of photovoltaic panel defect detection, paving the way for more reliable and accurate defect identification systems. This research will contribute to the automatic detection of surface defects in industrial production, ultimately enhancing production efficiency.

The paper shows III-V InAs/InAsSb type-II superlattice (T2SL) very long wavelength (VLWIR, 100% cut-off wavelength, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{\textit {cut}-\textit {off}}~\sim ~16.5~\mu $ </tex-math></inline-formula>m at 330 K) interband cascade photodetector designed to operate >300 K. The device circumvents the low quantum efficiency (QE) and resistance issues of the conventional “thick absorber” photovoltaic detectors designed for high operating temperature (HOT, >300 K) conditions. The 3-stage detector was grown by molecular beam epitaxy (MBE) on the lattice-mismatched GaAs substrates and GaSb buffer layer where stages were connected by the highly doped typical n+/p+ tunnel junctions. The time constant of the unbiased device reaches ~2.83 ns (210 K) and ~0.5 ns (330 K).

Hybrids combining with different materials, dimensions, and intrinsic characters have brought promising opportunities for new physics and device functions. In this work, the semimetal (1T′-MoTe2), p-type (WSe2), and n-type (MoS2) 2-D semiconductors have been integrated layer-by-layer, enabling the dual-junction photovoltaic detectors comprising of Schottky and p-n junction at the 1T′-MoTe2/WSe2 and WSe2/MoS2 heterogeneous interface, respectively. Due to the synergistic effect of the dual junction, the photo-excited electrons and holes can be efficiently separated and collected, resulting in a high photodetection performance with a responsivity (R) of 102 mA/W, detectivity (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${D}^{\ast } $ </tex-math></inline-formula>) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7 \times 10^{{10}}$ </tex-math></inline-formula> Jones, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {on}}$ </tex-math></inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {off}}$ </tex-math></inline-formula> ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.2 \times 10^{{4}}$ </tex-math></inline-formula> at zero bias under 635-nm illumination; all these parameters are much improved compared to that in single-junction-based device. Significantly, the values of R and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} _{\text {on}}$ </tex-math></inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} _{\text {off}}$ </tex-math></inline-formula> ratio of 1T′-MoTe2/WSe2/MoS2 are improved by about 20 times compared to 1T′-MoTe2/WSe2. This work proposes a dual-junction device architecture by connecting Schottky and p-n junctions in series, favorable for the improvement in photodetection performance.

A smart correction method for FTIR acquired response spectra of mid-infrared photovoltaic detectors

Multiplexed MHz-rate mid-infrared laser absorption spectroscopy for simultaneous in-chamber CO, CO2, H2O, temperature, and pressure in a rotating detonation rocket engine

Cutting-edge mid-wavelength infrared (MWIR) sensing technologies leverage infrared photodetectors, memory units, and computing units to enhance machine vision. Real-time processing and decision-making challenges emerge with the increasing number of intelligent pixels. However, current operations are limited to in-sensor computing capabilities for near-infrared technology, and high-performance MWIR detectors for multi-state switching functions are lacking. Here, we demonstrate a non-volatile MoS2/black phosphorus (BP) heterojunction MWIR photovoltaic detector featuring a semi-floating gate structure design, integrating near- to mid-infrared photodetection, memory and computing (PMC) functionalities. The PMC device exhibits the property of being able to store a stable responsivity, which varies linearly with the stored conductance state. Significantly, device weights (stable responsivity) can be programmed with power consumption as low as 1.8 fJ, and the blackbody peak responsivity can reach 1.68 A/W for the MWIR band. In the simulation of Faster Region with convolution neural network (CNN) based on the FLIR dataset, the PMC hardware responsivity weights can reach 89% mean Average Precision index of the feature extraction network software weights. This MWIR photovoltaic detector, with its versatile functionalities, holds significant promise for applications in advanced infrared object detection and recognition systems.

We demonstrate a quantum ratchet detector, which is a high-resistance photovoltaic mid-infrared detector based on an engineered spatial arrangement of subbands. In photovoltaic quantum-well photodetectors, in which unidirectional photocurrent is generated by asymmetric quantum-well structures, maximization of device resistance by suppressing undesired electron transports is crucial for minimizing noise. A semi-quantitative guideline suggests the significance of spatial separation between wavefunctions for reducing the conductance from the ground state. Here, we employ a step quantum well made of a shallow floor and a deep well. Photoexcited electrons are quickly transferred to a separated location from the ground state through fast resonant tunneling and phonon scattering, and then they are allowed to flow in only one direction. This architecture is made possible by the use of a GaAs/AlGaAs material system, and it achieves a resistance as high as 6.0 × 104 Ωcm2 with a single-period structure. Combined with optical patch antennas for responsivity enhancement, we demonstrate a maximum background-limited specific detectivity of 6.8 × 1010 cmHz1/2/W at 6.4 μm, 77 K for normal incidence, and a background-limited-infrared-photodetector temperature of 98 K.

This paper presents an innovative and simple method of high-frequency thermal impedance measurement using infrared (IR) technique. The method is based on the Fourier transformation of the input power signal and the thermal response of the object after supplying the heat source with square-wave current of different frequencies. The experiment was carried out using a single-detector, low-cost infrared system equipped with a photovoltaic detector module to measure the thermal impedance of an SMD thick-film resistor. Both the simulation using a compact thermal model and the measurement results are discussed.