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Low-dimensional nanostructures, especially one-dimensional materials, exhibit remarkable anisotropic characteristics due to their low symmetry, making them promising candidates for polarization-sensitive photodetection. Here, we present a chemical vapor deposition synthesis method for tellurium suboxide (TeOx), confirming the practicality of photodetectors constructed from TeOx nanowires (NWs) in high-responsivity, broadband, and polarization-sensitive detection. By precisely controlling the thermodynamics and kinetics of TeOx NWs growth, we achieve large-scale growth of TeOx NWs with highly controllable dimensions and propose a method to induce intrinsic built-in strain in TeOx NWs. Photodetectors based on quasi-one-dimensional TeOx NWs with ohmic contact demonstrate broadband spectral response (638–1550 nm), high responsivity (13 700 mA·W−1), and superior air stability. Particularly, owing to the inherent structural anisotropy of the photodetectors, they exhibit polarization-sensitive photodetection, with anisotropy ratios of 1.70 and 1.71 at 638 and 808 nm, respectively. [ABSTRACT FROM AUTHOR]

We demonstrate the change of the sign from negative to positive of the self-powered photovoltaic photocurrent in core–shell n-InGaN/p-GaN nanowire heterojunctions within the visible to UV wavelength range. Such dual-polarity photodetectors are of broad interest to provide extended functionalities for optoelectronic devices, starting with dual-wavelength photodetectors. The physics of the photocurrent sign reversal is understood by a well-balanced selective absorption and photocarrier generation, photocarrier transfer, and thermal excitation paths in the core–shell n-InGaN/p-GaN nanowire functional absorber with different bandgap energies and opposite inner- and surface energy band bendings. The basic dual-wavelength photodetector operation parameters are given. [ABSTRACT FROM AUTHOR]

Solution-processed organic photodetectors (OPDs) with spectral response in the near-infrared (NIR) region have broad applications such as in industries, spectroscopic/medical instruments, communications, image sensing, and environmental monitoring. OPDs capable of selective spectral response are particularly appealing for applications including secure optical data link and color image sensing systems. Here, we report an organic photodetector with a highly selective spectral response to near-infrared radiation without the use of a color filter. The operation of the OPDs takes advantage of a charge collection narrowing effect, resulting in a narrowband response at 760 nm with a full width at half maximum of 47 nm and an external quantum efficiency of 46%. Owing to the features of the narrowband response in NIR, our organic photodetectors are used as optical signal receivers for an optical communication system, which achieves a data transmission rate of 12.6 kB/s with a low bit error rate on the order of 10−4. We further investigated the response bandwidth in devices with different active layer thicknesses and area size and their response bandwidth under different reverse bias conditions as well. The optimized device shows a −3 dB response bandwidth of 3.02 MHz and a data transmission rate of 1.41 Mbit/s. The results highlight the promising potential of the nonfiltered OPDs for a variety of applications, including light communication, short-range data transmission, and image sensing. [ABSTRACT FROM AUTHOR]

The absorption of a free-standing ultra-thin film supporting a single resonant mode is, in principle, limited to 50%. Based on the degenerate critical coupling (DCC) of dipole modes, silicon Mie resonators can overcome the absorption limit and achieve perfect absorption in the green light range. DCC requires that the radiative loss of each dipole mode matches material loss. Due to the material properties of silicon, the material loss varies with wavelength. Therefore, flexible tuning of radiative loss to match the wavelength-dependent material loss is crucial for realizing DCC-based perfect absorbers. In this study, we propose that a 45-degree rotation of cubic Mie resonators enhances the radiative loss of electric dipole mode. Hence, the DCC-based perfect absorption can be extended to the violet light range. In addition to applications in photodetectors and imaging sensor pixels, the proposed perfect absorber has great potential to become nonlinear elements based on the photothermal effect for photonic neuromorphic computing due to its temperature-dependent scattering. [ABSTRACT FROM AUTHOR]

Hyperdoping Si with transition metals to form intermediate bands for infrared absorption has attracted attention recently for producing sub-bandgap photoconductivity. In particular, Si hyperdoped with Au has been demonstrated to exhibit optoelectronic response at 1550 nm. However, the reported external quantum efficiencies (EQEs) are low, and the device fabrication processes had not been optimized. In this paper, we demonstrate a significant improvement in sub-bandgap EQE through modification of the material and device fabrication processes. By increasing the Si:Au layer thickness, modification of device design, and formation of Ohmic contacts, the EQE was measured to be as high as 0.44% at 1550 nm, nearly two orders of magnitude higher than previous reports from similar devices. Additionally, the EQE was measured to be in the 10-3 range for wavelengths as long as 2.4 μ m. The EQE spectrum showed features that were attributed to defect levels from a substitutional Au acceptor defect. The above bandgap EQE showed gain in one device. Thermal annealing at 300 ° C does not improve the efficiency of Si:Au photodiodes. These results demonstrate the viability of Au-hyperdoped Si for infrared detection below the bandgap of Si. [ABSTRACT FROM AUTHOR]

The acid-resistant tungsten trioxide photoelectrochemical solid–liquid ultraviolet (UV) photodetector uses a thin film of tungsten trioxide as the photoelectrode, forming a stable heterojunction with the electrolyte. This study employed band theory and double electron layer theory to analyze the mechanisms underlying the effect of pH on the redox potential and photocurrent, utilizing the ion product constant of water and the Nernst equation. By applying the principles of energy band theory and the two-electron layer model, the electron transfer process was analyzed and explained. These findings hold significant promise for enhancing solid–liquid heterojunction UV photodetectors. Tungsten trioxide has fast response and high sensitivity under extreme conditions. The device performance of WO3 nanosheets fabricated by annealing at 300 °C for one hour is excellent, including a rise time of 0.7 s, decay time of 6.8 s, photosensitivity of 1.90, and photoresponsivity of 2.31 mA/W. 0.5M sulfuric acid produced the highest photocurrent (5.46 μA) and sensitivity (14.07). This material has potential applications in optoelectronics, catalysis, sensing, water treatment, and air purification. [ABSTRACT FROM AUTHOR]

In recent years, inorganic lead-free perovskite materials have garnered attention for their non-toxicity, high carrier mobility, and strong light absorption capabilities, showing promising application prospects in photoelectric sensing. CsCu2I3 perovskite has been mentioned as one of the representatives and as a potential material for short-wavelength optoelectronic devices. This study employs a one-step chemical vapor deposition (CVD) process to fabricate CsCu2I3 thin films, which exhibit a vibrant yellow emission at 560 nm. Ultraviolet photodetectors utilizing CsCu2I3 films demonstrate an exceptional responsivity and a detectivity of 1.43 A/W and 1.15 × 1012 Jones (254 nm, 5 V bias), along with rapid response times (trise ≈ 50 ms, tdecay ≈ 70 ms). Moreover, this work examines the factors affecting device performance, including wavelength, operating voltage, and film thickness. It presents a straightforward, ecofriendly CVD method for producing lead-free perovskite films and optoelectronic devices, which has significant implications for the development of lead-free perovskite-based photoelectric technologies. [ABSTRACT FROM AUTHOR]

Light absorption enhancement in a 1.5 μm thick mercury–cadmium–telluride (Hg0.762Cd0.238Te, MCT) layer at room temperature utilizing 1D dielectric grating at mid-wave infrared (MWIR) wavelengths (3–5 μm) has been theoretically investigated. The optimized dielectric grating facilitates light diffraction and scattering into the MCT-absorbing waveguiding layer resulting in an increased lateral optical path. The light absorption was improved from ∼37.5% to ∼71% (TE) and ∼70% (TM) at normal incidence. With enhanced absorption, the photocarrier generation rate in the thin layer would be comparable to a bulk 5 μm thick MCT layer. A ∼3× reduction in the MCT layer thickness without compromising absorption has the potential for realizing infrared photodetectors with improved sensitivity at conventional operating temperatures and/or elevated operating temperatures. [ABSTRACT FROM AUTHOR]

Photomultiplication-type organic photodetectors (PM-OPDs) have been stimulating more and more researchers' interest owing to their extremely high external quantum efficiency (EQE). To prepare high-performance PM-OPDs with a broadband spectral response range from visible to near-infrared and investigate the role of energy levels of the donor and acceptor on its responsiveness, the non-fullerene acceptor Y6 was added into the P3HT:PC71BM system in this work. The photomultiplication phenomenon with the highest EQE has been achieved under both forward and reverse bias when the ratio of Y6 in two acceptors approaches 80 wt. %. The introduction of Y6 not only promotes the formation of moderate hole traps in the active layer but also results in an appropriate amount of low injection barriers to allow more electron injection from the external circuit. Therefore, the spectral response of the device with 80 wt. % Y6 has been broadened from 750 to 950 nm, and the champion EQE of 15 691% at 10 V and 7639% at −20 V at 850 nm was achieved. This work reveals the importance of hole-trapping ability determined by the energy level difference between the donor and the acceptor for the selection of the multiplication system and provides a scheme for the design of high-performance broadband PM-OPDs. [ABSTRACT FROM AUTHOR]

AlN/amorphous Ga2O3 heterojunction photodetectors were fabricated to achieve solar-blind UV detection. The responsivity and detectivity of the photodetector on a native substrate are 150% and 21.8% higher than those on a heterogeneous substrate at a 20 V bias, reaching 8.31 A W−1 and 3.24 × 1014 Jones, respectively. The built-in electric field enables self-powered UV detection without an external power supply. The addition of a nanocolumnar AlN structure significantly improved the performance of the photodetector, achieving a photo-to-dark current ratio and responsivity up to 2.11 × 107 and 9.17 mA W−1 at 0 V bias. The fabricated photodetector has demonstrated self-powered and high-sensitivity UV detection. [ABSTRACT FROM AUTHOR]

This study investigates a photodetector design using the nontoxic, all‐inorganic perovskite material RbGeI3, which is distinguished by its efficient light absorption and excellent photoelectric conversion properties. Incorporating copper bismuth thiocyanate (CBTS) and indium gallium zinc oxide layers, this design enhances charge transport, leading to a photodetector that exhibits exceptional sensitivity across the visible spectrum, along with a peak responsivity of 0.63 A W−1 and a detectivity of 1.37 × 1013 Jones in the near‐infrared (NIR) at 900 nm. The proposed photodetector exhibits wide‐spectrum detection, encompassing both the visible range and the NIR region. These results position RbGeI3 and CBTS as compelling alternatives to traditional photodetector materials such as Si‐Ge, InGaAs, ZnO, and GaN. Validation is achieved through simulations using the SCAPS‐1D simulator, underscoring the potential of perovskite materials for advanced photodetector applications. [ABSTRACT FROM AUTHOR]

The In x Ga 1 − x A s y Sb 1 − y alloy was studied in epilayers and photodiodes grown lattice matched to GaSb across a comprehensive composition range, 0 ⩽ x ⩽ 0.3 , as a promising technology to support the extended short-wave infrared region ∼ 1.7 − 3 µ m. Low background carrier concentrations between 6 × 10 14 and 1 × 10 15 cm − 3 were achieved in all samples, reducing with In fraction. Both the absorption coefficient and external quantum efficiency were found to increase with indium fraction, up to ∼ 10 4 cm − 1 and 70% without an AR coating, respectively. Counter to the fundamental bandgap dependence, leakage current density initially reduced with the addition of low In and As fractions, before rising as the fractions increased and the bandgap reduced further. These properties resulted in specific detectivity reaching a maximum in the sample with x = 0.043, before decreasing towards higher alloy fractions. It is concluded that for moderate In fractions, the InGaAsSb alloy offers clear potential to improve on the disappointing material and photodiode properties of GaSb and support emerging SWIR sensing applications. However, development of fabrication and passivation technology is required to fully exploit this potential. [ABSTRACT FROM AUTHOR]

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]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of portable X‐ray detectors is necessary for diagnosing fractures in unconscious patients in emergency situations. However, this is quite challenging because of the heavy weight of the scintillator and silicon photodetectors. The weight and thickness of X‐ray detectors can be reduced by replacing the silicon layer with an organic photodetectors. This study presents a novel bithienopyrroledione‐based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer (~700 nm), owing to the symmetric backbone and highly soluble molecular structure of bithienopyrroledione. The ability of bithienopyrroledione‐based polymer donor to strongly suppress the dark current density (Jd ~ 10−10 A cm−2) at a negative bias (−2.0 V) while maintaining high responsivity (R = 0.29 A W−1) even at a thickness of 700 nm results in a maximum shot‐noise‐limited specific detectivity of Dsh* = 2.18 × 1013 Jones in the organic photodetectors. Printed organic photodetectors are developed by slot‐die coating for use in X‐ray detectors, which exhibit Dsh* = 2.73 × 1012 Jones with clear rising (0.26 s) and falling (0.29 s) response times upon X‐ray irradiation. Detection reliability is also proven by linear response of the X‐ray detector, and the X‐ray detection limit is 3 mA. [ABSTRACT FROM AUTHOR]

Researchers have created a modern infrared (IR) sensor that is both super-sensitive and highly flexible. This remarkable device possesses impressive properties of exceptional sensitivity (24,000%), high responsiveness (1.25 A/W), and fast response time (3 ms). This innovation stands out for its unique construction: an ultrathin layer of lead sulfide (PbS) deposited on a standard Whatman filter paper. This design achieves a photo-current 32 times greater than previous record-holding PbS thin films. The key advantage is its unmatched flexibility. This sensor can bend and flex without breaking, maintaining its IR detection capabilities even after enduring extreme bending cycles. This breakthrough paves the way for a new era of wearable IR photo sensors, flexible electronics, and medical applications. [ABSTRACT FROM AUTHOR]

Efficient photoelectrochemical photodetectors based on WSe2/rGO have been fabricated using an annealing process. The initial performance enhancement of these devices was primarily attributed to the improved bandgap structure of WSe2 and the high carrier mobility of rGO, which facilitated an efficient transition of valence band electrons to the conduction band. Upon this understanding, a comparison between bulk WSe2 and WSe2 nanosheets (WSe2 NSs) was conducted. It was found that, at a bias voltage of 0.6 V, the photocurrent density of WSe2 NSs devices was 76% higher than that of similar bulk WSe2 devices, reaching 0.044 μA/cm2. Owing to the significant advantages of rGO, extensive testing of various WSe2 to rGO ratios was performed, identifying the precise composition that optimized photoelectric performance. Notably, under conditions of 0.5 M Na2SO4 electrolyte, 120 mW/cm2 irradiance, and 0.6 V bias potential, the devices achieved a photocurrent density of 0.64 μA/cm2, which is approximately 25.72 times higher than that of bulk WSe2 and 14.61 times more than WSe2 NSs. Moreover, the photoresponse trended upward with increasing irradiation intensity. Specifically, when the irradiation intensity was increased to 160 mW/cm2 and the bias voltage was raised from 0 V to 0.6 V, the photoresponsivity increased by 5.8 times, from 1 μA/W to 5.8 μA/W. The photodetectors constructed using the optimal WSe2/rGO ratio exhibited no significant performance degradation during a 4000-s cyclic on/off test, demonstrating their robustness under operational conditions. This study highlights the substantial potential of WSe2/rGO hybrids in enhancing the performance of photoelectrochemical photodetectors. [ABSTRACT FROM AUTHOR]

The photomultiplication type organic photodetectors (PM‐OPDs) are prepared with structure of ITO/PNDIT‐F3N/F8BT/Y6‐1O:P3HT (100:3, wt/wt)/Al, containing hole traps formed with P3HT surrounded by Y6‐1O in active layers. The PM‐OPDs exhibit external quantum efficiency (EQE)>100% in the spectral response range from 310 to 910 nm, resulting from electron tunneling injection assisted by trapped hole near ITO electrode. The incorporation of F8BT buffer layers can induce the markedly decreased dark current density (JD) due to the large electron injection barrier. The light current density (JL) of PM‐OPDs exhibits slightly decreased by inserting F8BT buffer layers due to the enhanced electron tunneling injection assisted by the more trapped holes near ITO electrode. The signal‐to‐noise ratio (SNR) of PM‐OPDs achieves over 40‐fold increment by inserting appropriate thickness of F8BT buffer layers, resulting from the markedly decreased JD and reasonably high JL. The optimal PM‐OPDs exhibit excellent photodetection capability with EQE of 4200% at 360 nm and 6600% at 850 nm, associated with the specific detectivity of 3.9 × 1011 Jones at 360 nm and 9.7 × 1011 Jones at 850 nm. [ABSTRACT FROM AUTHOR]

Graphene electrodes draw considerable attention in solar‐blind ultraviolet (SBUV) detection owing to their unique features including high ultraviolet (UV) transparency and superior intrinsic carrier mobilities. However, their adoption comes with challenges, as the most commonly used preparation technique, i.e., the dry transfer process, is challenging to achieve mass production. In this work, graphene/β‐Ga2O3 heterojunction photodetectors processed by wet transfer are reported. Benefiting from the UV‐transparent electrode and heterojunction, both the responsivity and response speed are improved. The characteristic of the graphene/β‐Ga2O3 interface is analyzed by the current–voltage (I–V) and capacitance–voltage (C–V) curves, featuring a high‐quality junction. Operated at zero bias, the photodetector exhibits a low dark current of less than 1 pA and a high response speed of less than 1 ms. An excellent UV‐C/visible rejection ratio is also achieved. Importantly, the photodetector performs excellent reproducibility and performance stability. This results provide a new perspective for the mass production of graphene/Ga2O3 integrated devices, enabling high‐performance Ga2O3 photodetector arrays. [ABSTRACT FROM AUTHOR]

Self‐powered photodetectors (PDs) have gained significant attention in recent years due to their ability to operate without external power. Strengthening the built‐in electric field (Ebi) of these devices is crucial for efficient carrier separation and transport. However, the disordered energy level arrangement within mixed halide perovskites (MHP) often conflicts with the energy levels constructed by the external interface, weakening the Ebi and thus affecting the performance of self‐powered PDs. In this study, a bias‐induced gradient bandgap of bulk MHP is proposed for high‐performance self‐powered photodetectors. The vector superposition of the bias‐induced gradient bandgap with the interface electric field significantly boosts the Ebi of the device, providing a powerful driving force for the separation and transport of photogenerated carriers. The obtained device exhibits exceptional performance, including an ultra‐fast response time of 1.14/1.75 µs, a large specific detectivity of 7.27 × 1012 cm Hz1/2 W−1, an ultra‐high responsivity of 0.49 A W−1, and an external quantum efficiency of 93.5% at 0 V bias. Furthermore, this strategy is also demonstrated in lateral structure photodetector. This work offers valuable guidance for achieving high‐performance MHP‐based self‐powered PDs through bias‐induced gradient bandgap optimization. [ABSTRACT FROM AUTHOR]

Materials with low‐dimensional (1D–2D) structures hold significant promise for electronic and optoelectronic applications owing to their distinctive structural features and inherent properties. These characteristics render them of substantial interest across various scientific domains, particularly in applications related to energy storage, such as supercapacitors and lithium‐ion batteries. Due to their high surface‐to‐volume ratios and unique geometric properties, low‐dimensional materials have attracted considerable attention in developing advanced broadband photodetectors (PDs) with enhanced performance capabilities. In this study, for the first time, the study reports self‐powered broadband PDs based on vertical‐core‐shell niobium diselenide (NbSe2)‐ZnO nanorods (ZNRs), which are produced using a hydrothermal method. Remarkably, the NbSe2(3 ml) doped ZNRs‐based device exhibits outstanding responsivity of 0.62, 23.21, 5.35, 1.11, 0.30 AW−1, detectivity of 2.15 × 1010, 4.10 × 1011, 1.62 × 1011, 8.83 × 1010, 1.42 × 1011 Jones, and high sensitivity of 8.74 × 104%, 5.78 × 105%, 2.71 × 105%, 2.79 × 105%, 1.43 × 105% at wavelengths of 365, 456, 532, 632, and 850 nm, respectively, at zero bias. The NbSe2(3ml)‐ZNRs device showed a rapid response and fall times of 37 ms and 40 ms, enabled by NbSe2 superconductivity. The concept introduced in this study is strongly believed to possess significant potential and can be extensively applied in developing next‐generation integrated optoelectronic, clean energy technology, and photodetection devices based on 1D/2D nanostructures. [ABSTRACT FROM AUTHOR]

Light propagation in complex media results in strong scattering. While wavefront shaping (WFS) enables the focusing of light at depth, its speed is mainly limited by the frame rate of the area‐array detectors. The photodetector has been used to achieve fast focusing, but it cannot record sufficient speckle information, limiting its applications in multi‐point focusing and non‐invasive focusing. Here, a method for invasively or non‐invasively focusing through scattering media is proposed by using 1D speckle signals as feedback for wavefront shaping. Experimentally, not only invasive multi‐point focusing can be realized, but also by maximizing the contrast of linear fluorescent 1D speckle signals, non‐invasive focusing can be achieved, suggesting the effectiveness of the proposed method. This approach can be generalized to the utilization of linear array detectors in WFS and may hold interesting prospects for rapid focusing light within deep biological tissues. [ABSTRACT FROM AUTHOR]

Over the past several decades infrared (IR) photodetectors have received wide attention due to their important applications. 2D materials, distinguished by their unique electronic structures, ultimate dimensional confinement, and robust light‐matter interactions, provide a promising candidate for fabricating future IR photodetectors. However, there is a lack of reports concerning the practical industrial applications of these 2D photodetectors, despite that some of these 2D photodetectors have demonstrated performance exceeding that of commercial photodetectors. In this work, a case study on 2D Bi2O2Se nanoplate near‐infrared photodetectors from the perspective of practical applications is presented. With the characterization method used for nano detectors, the 2D Bi2O2Se photodetector exhibits a responsivity of 212.5 A W−1, a specific detectivity of 4.99 × 1011 Jones and an external quantum efficiency of 26 887.68% at wavelength of 980 nm, while with the traditional characterization method the photodetector shows a responsivity of 0.13 A W−1 and a specific detectivity of 2.26 × 106 Jones and an external quantum efficiency of 17.87% at wavelength of 900 nm. The Bi2O2Se nanoplate photodetector also presents good passive imaging quality in the near‐infrared wavelength region. These results suggest the great potential of Bi2O2Se nanoplate photodetectors for practical applications. [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]

Anisotropic wet etching of silicon (Si) has been known for decades, but the extraordinary capabilities of this technology to provide highly ordered microphotonic arrays have received limited attention in previous studies. It is shown that these capabilities include: i) a unique self‐terminating etching nature − crucial for achieving uniform arrays over centimeter‐scale wafers, ii) an extraordinary smoothness of the slow‐etching (111) planes, and iii) a precise geometry control including the extent micropyramids or micropyramidal voids are truncated. The combination of these properties transforms this technology into a versatile platform for novel detector and emitter applications in Si photonics. The optical properties of such arrays are studied by finite‐difference time‐domain modeling in two realms represented by different boundary conditions (BCs). Periodic BCs result in Talbot self‐images experimentally observed in this work. Perfectly matched layer BCs describe mesoscale interference effects resulting in the subwavelength focusing properties of micropyramids. Enhancements in the performance of mid‐wave infrared (MWIR) focal plane arrays are demonstrated by monolithic integration of Si micropyramids with silicon‐platinum silicide Schottky barrier photodetectors. Finally, it is shown that Si micropyramidal arrays can be used to enhance light extraction and directionality of quantum sources and infrared scene projectors. [ABSTRACT FROM AUTHOR]

Ascribing to the low power consumption, self‐powered photodetectors (SPPDs) have promising applications in optical communication and photoelectric imaging. Aiming to improve the performance of SPPDs, many efforts have been devoted to exploring the semiconductor‐heterojunction candidates. However, key parameters of SPPDs, especially the responsivity and response time, still lag behind those of the standard photodetectors. Here, with the modification of the transport behavior, ultra‐high‐performance SPPDs are fabricated based on the reported Sb2Se3/ZnO heterojunction. Keeping the broadband detection from infrared to UV region, the SPPDs achieve increased responsivity and detectivity of 0.38 A W−1 and 1.40 × 1013 Jones, respectively. Especially, according to the cut‐off frequency measurements, the response time is improved to 93.5/75.0 ns, which is in a microsecond, even millisecond level for most of the current SPPDs. These studies further reveal the mechanism of the performance modification and indicate that this method can be applied to fabricate imaging arrays. With the combination of the experimental results, we provide an effective method for enhancing the performance of SPPDs toward their applications. [ABSTRACT FROM AUTHOR]

2D/3D van der Waals heterostructures provide an excellent platform for high-performance optoelectronic systems by combining the intrinsic properties of 2D and 3D materials. In this study, we fabricate and study a type II ReS2/Si van der Waals 2D/3D vertical heterojunction with multi-mode photodetection. In the dark, the heterojunction exhibits diode-like behavior with a low reverse current and a high rectification ratio of ∼103. Under illumination, the device shows a linear response to the light intensity. The ReS2/Si photodetector exhibits stable and repeatable switching behavior and can be operated in self-powered mode with a responsivity of about 0.10 mA/W at 10 mW incident power and a time response of 300 μs. Based on first-principles calculations, we propose a model to elucidate the photoconduction mechanisms occurring in the ReS2/Si heterostructure. [ABSTRACT FROM AUTHOR]

Photodetectors are now indispensable in our daily lives, and there is a pressing need to explore new materials and mechanisms that can push the boundaries of device performance. Two-dimensional (2D) van der Waals (vdW) semiconductors have emerged recently as a promising material platform with exceptional optoelectronic properties, making them particularly suitable for high-performance photodetectors. However, photoinduced carrier generation in conventional 2D vdW photodetectors are usually limited, and new mechanisms need to be introduced to enhance device performance. Herein, we report a high-performance avalanche photodetector based on selenium (Se) nanoflakes. Our device achieves a high photoresponsivity (R) and specific detectivity (D*) of 361 A·W−1 and 2.4 × 1012 Jones, respectively. These figures of merit are two orders of magnitude higher than that in conventional Se photoconductive photodetectors. As a large bandgap vdW semiconductor, the Se channel allows the application of an extremely large bias voltage across it, and the resulting high electric field leads to the avalanche multiplication of carriers, which lays the groundwork for the improved device performance. [ABSTRACT FROM AUTHOR]

Polarization‐sensitive solar‐blind ultraviolet (UV) photodetectors are essential in both civilian and military applications. 1D perovskites derivative Rb2CuCl3 holds promise for polarization‐sensitive solar‐blind UV photodetectors due to its wide direct bandgap, anisotropic crystal structure, and long carrier lifetime. However, no studies on the polarization properties of Rb2CuCl3 are reported. Here, the electronic structural anisotropy of Rb2CuCl3 is confirmed by calculating the partial charge density distribution in the ac‐plane and bc‐plane. Then, the Raman‐active modes and corresponding atomic vibration modes are explored within the bc‐plane through joint experimental and theoretical Raman spectroscopy. Besides, angle‐resolved Raman, photoluminescence, and absorption spectroscopy reveal the intriguing anisotropic photoelectric characteristics of Rb2CuCl3 microwires (MWs). By using single Rb2CuCl3 MW as the photoactive layer, a polarization‐sensitive solar‐blind UV photodetector is fabricated, showing high photoresponsivity of 78 mA W−1 and photocurrent anisotropy ratio of ≈1.7 at 265 nm. Importantly, the proposed photodetectors without encapsulation exhibit excellent stability in ambient air, retaining the original photocurrent after two months, showcasing practical applicability. This study underscores the promise of Rb2CuCl3 for high‐performance polarization‐sensitive solar‐blind UV photodetectors, contributing valuable insights into its electronic structure, photoelectric properties, and practical applicability. [ABSTRACT FROM AUTHOR]

Short‐wave infrared (SWIR) photodetectors utilizing quantum dot (QD) material systems, harnessed through the quantum confinement effect to tune the absorption wavelength, offer an attractive avenue for the development of cost‐effective and solution‐processed photodetectors compared to the relatively expensive compound semiconductor photodetectors. However, the pores between the QDs and poor chemical stability after surface modification have impeded the practical application of quantum‐dot‐based photodetectors. In this study, high‐gain SWIR photodetector is demonstrated and achieved by incorporating PbS QD into the Cs2AgBiBr6 halide‐based double perovskite matrix, as confirmed by X‐ray diffraction, transmission electron microscope, and energy dispersive spectrometer. The thin film structure and detailed local structure are revealed by 2D grazing‐incidence wide and small‐angle X‐ray scattering. The resulting PbS@Cs2AgBiBr6‐based SWIR photodetector exhibits remarkable performance with a responsivity and detectivity of 15000 A W−1 and 1.31 × 1012 cm Hz1/2 W−1, respectively. This study offers valuable insights into the design of composite materials for high‐gain SWIR photodetectors. [ABSTRACT FROM AUTHOR]

Photodetectors play a critical role in space lidars designed for scientific investigations from orbit around planetary bodies. The detectors must be highly sensitive due to the long range of measurements and tight constraints on the size, weight, and power of the instrument. The detectors must also be space radiation tolerant over multi-year mission lifetimes with no significant performance degradation. Early space lidars used diode-pumped Nd:YAG lasers with a single beam for range and atmospheric backscattering measurements at 1064 nm or its frequency harmonics. The photodetectors used were single-element photomultiplier tubes and infrared performance-enhanced silicon avalanche photodiodes. Space lidars have advanced to multiple beams for surface topographic mapping and active infrared spectroscopic measurements of atmospheric species and surface composition, which demand increased performance and new capabilities for lidar detectors. Higher sensitivity detectors are required so that multi-beam and multi-wavelength measurements can be performed without increasing the laser and instrument power. Pixelated photodetectors are needed so that a single detector assembly can be used for simultaneous multi-channel measurements. Photon-counting photodetectors are needed for active spectroscopy measurements from short-wave infrared to mid-wave infrared. HgCdTe avalanche photodiode arrays have emerged recently as a promising technology to fill these needs. This paper gives a review of the photodetectors used in past and present lidars and the development and outlook of HgCdTe APD arrays for future space lidars. [ABSTRACT FROM AUTHOR]

The self‐plasticization, i.e., the increase in the polymer chains' mobility by including its monomer, has a major impact on a polymer's structural, thermal, and mechanical properties. In this study, differential scanning calorimetry (DSC), optical and Raman microscopies, thermo‐mechanical analysis (TMA), size exclusion chromatography equipped with a multi‐angle light scattering detector (SEC‐MALS), and X‐ray diffraction analysis (XRD) are used to investigate the effect of thermally induced self‐plasticization of poly‐(p‐dioxanone), PDX, on the crystal growths from the amorphous and molten states. Significant changes in the crystallization behavior and mechanical properties of PDX are found only for samples self‐plasticized at the depolymerization temperature (Td) above 150 °C. The intense self‐plasticization leads to the decrease of the crystallization temperature, increase of the crystal growth rapidity, disappearance of the distinct α→α' polymorphic transition, reduction of the overall melting temperature, and segregation of the redundant monomer. Although the morphology of the crystalline phase has a major impact on the mechanical properties of PDX, the self‐plasticization itself does not seem to result in any major changes in the magnitude, localization, or morphology of formed crystallites (these are primarily driven by the temperature of crystal growth). The manifestation of the variable activation energy concept is discussed for the present crystallization data. [ABSTRACT FROM AUTHOR]

Sensitive high‐energy photon detection from UV to X‐ray and high‐resolution array imaging are critical for medical diagnosis, space exploration, and scientific research. The key challenges for high‐performance photodetector and imaging arrays are the effective material and device design strategies for the miniaturization and integration of the device. Here, photon‐controlled diodes (i.e., the detector has rectifying characteristics only under light irradiation) are proposed for high‐resolution and anti‐crosstalk array imaging applications without integrating the switching element. Based on ultra‐wide bandgap semiconductor Ga2O3, the sensitive DUV/X‐ray photon‐controlled diodes are realized by the design of high‐resistance Ga2O3 film and high‐barrier contact. The device exhibits remarkable detection performance, including high photo‐responsivity (168 A W−1) and specific detectivity (1.45 × 1015 Jones) under DUV illumination, as well as a high sensitivity (1.23 × 105 µC Gyair−1 cm−2) under X‐ray light. Moreover, the low dark current and excellent rectification characteristics are obtained. Furthermore, its potential for high‐density and anti‐crosstalk array imaging applications is verified. These results not only bring forth new insights in the implementation of high‐performance DUV/X‐ray photodetector, but also pave a feasible way to realize high pixel density detector array through the simplified fabrication process for high‐resolution imaging applications. [ABSTRACT FROM AUTHOR]

Films with honeycomb‐like structures have became ideal network structures for the development of flexible photodetectors due to their superior mechanical stability and merits in large active surface area, high carrier transport efficiency and well light absorption capacity. In this work, a honeycomb‐like Bi2S3 film with centimeter‐scale (2 cm × 2 cm) is synthesized on an ultrathin flexible fluorophlogopite mica substrate, which consists of a well‐stabilized arrangement of triangular unit structures forming an interconnected network structure. Based on the as‐grown honeycomb‐like Bi2S3 film, a flexible photodetector with a broadband response from ultraviolet to infrared is constructed, which displays the highest responsivity (Rλ) of 611.2 mA W−1 and specific detectivity (D*) of 4.77 × 1010 Jones. And at 850 nm light illumination, there is nearly no deterioration in Rλ and D* of the Bi2S3 flexible photodetector after successive multiple bends, benefiting from the excellent structural stability of the triangular honeycomb network structure. Notably, the device maintains excellent detection performance after 1 week of prolonged bending in air without any encapsulation, and its photocurrent can still reach 90.39% of the initial photocurrent. In addition, the device also exhibits favorable durability, cycle stability, as well as high‐definition imaging ability in bending state and after bending recovery. [ABSTRACT FROM AUTHOR]

Long‐wave infrared photodetectors play an indispensable role in a variety of fields such as science, technology, engineering, and medicine. However, to date, most conventional long‐wave infrared photodetectors need to be operated under low temperature to meet the performance requirements. This can lead to a series of problems such as large device volume and high operating cost. Therefore, it is urgent to explore novel long‐wave photosensitive materials. In recent years, the development of nanotechnology has opened a new door for long‐wave infrared photodetection. Herein, pulsed‐laser deposition is successfully applied to the preparation of Ge‐doped BiTe (GBT) thin films. Importantly, the corresponding GBT photodetector exhibits excellent long‐wave infrared photosensitivity. Specifically, upon 10.5 µm illumination, the responsivity, external quantum efficiency, and detectivity reach 1.41 mA W−1, 0.017%, and 1.96 × 106 Jones, respectively. Moreover, a fast response rate with the rise/decay time down to 42.5/41.1 µs is realized. On this basis, the GBT photodetector is used as the receiving unit for optical signals to achieve proof‐of‐concept long‐wave optical information transmission application. On the whole, this study provides a new material platform for long‐wave optoelectronic sensing. [ABSTRACT FROM AUTHOR]

Photodetectors with good polarization detection ability are promising in many applications, such as remote sensing imaging and environmental monitoring. However, the traditional polarization detection systems fall short in meeting integration demands of the integrated‐circuits field due to additional optical elements. The emerging 2D materials with in‐plane anisotropic structures provide a possible method to fabricate remarkable polarization detectors. Modulating the band structure by gate voltage is an important strategy for developing optoelectronic devices. Herein, a polarized photodetector based on PdSe2/MoS2 out‐of‐plane heterojunction is fabricated. Due to its unique out‐of‐plane heterostructure, the device exhibits excellent photoresponse characteristics and polarization sensitivity, including an excellent responsivity of 10.19A/W, an extremely high external quantum efficiency of 2429%, a fast rise/decay time of 68/192 µs, and a high photocurrent anisotropy ratio of 3.09. Based on the adjustment of the built‐in electric field through gate voltage, the performance of the device can be accordingly modulated. As the gate voltage increases from −30 to 30 V, the responsivity gradually increases from 7.5 to 13A/W and the detectivity increases from 1.53 to 2.63 × 109Jones. Finally, its olarization imaging ability is demonstrated at different polarization angles. The findings indicate that PdSe2/MoS2 devices exhibit significant potential for polarized photoelectric detection. [ABSTRACT FROM AUTHOR]

At the interface of 2D heterostructures, the presence of defects and their manipulation play a crucial role in the interfacial charge transfer behavior, further influencing the device functionality and performance. In this study, the impact of deliberately introduced photo‐active defects in the h‐BN layer on the interfacial charge transfer and photoresponse performance of a metal‐insulator‐semiconductor type heterostructure device is explored. The formation and concentration of defects are qualitatively controlled using an inductive coupled plasma treatment method, as evidenced by enhanced h‐BN defect emission and more efficient optically induced doping of graphene at the graphene/h‐BN interface. Besides, the use of the h‐BN layer between graphene and WS2 not only suppresses charge carriers in the dark state, but also promotes the separation of photo‐generated electron‐hole pairs and interfacial charge transfer due to the existence of defect levels, leading to orders of magnitude improvement in the light on/off ratio and self‐driving performance of the heterostructure photodetector. This strategy of controlling defect states in the insulating layer provides a new approach to optimize the charge transfer processes at the 2D interfaces, so as to expand its potential applications in the fields of electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Colloidal quantum dots (CQDs) with tunable bandgaps in the NIR‐SWIR range are highly valued for infrared applications including LiDAR, interactive displays, and biometrics. Particularly, for environmental considerations, photodetectors (PDs) using InAs CQDs are actively being explored. However, their performance still lags behind that of Pb‐based devices. Herein, an effective strategy to improve the photodetection characteristics of InAs CQD PDs by enhancing the incident photon usage is presented. By engineering the solvent of InAs CQD ink to increase volatility, the controllable range of absorber layer thickness is substantially extended. Then, the thickness‐ and bias‐dependent performance of InAs CQD PDs are systematically studied, guided by optical simulations. Under optimal conditions, an external quantum efficiency (EQE) of 79%, a responsivity of 0.6 AW−1–the highest reported for InAs CQD photodiodes, and a detectivity of 3.1 × 1011 Jones at 940 nm are achieved. Furthermore, it is found that increasing the absorber layer thickness reduces device capacitance, resulting in a faster response time of 46 ns. This study provides optical and electrical insights into how absorber layer thickness affects InAs CQD PD performance and outlines design principles for high‐performance optoelectronic devices with specified light‐absorbing layers, paving the way for the development of advanced optoelectronic devices. [ABSTRACT FROM AUTHOR]

Nanomaterials have superior electronic, optical, and mechanical properties making them highly suitable for a range of applications in optoelectronics, biomedical fields, and photonics. Nanomaterials‐based IR detectors are rapidly growing due to enhanced sensitivity, wide spectral range, and device miniaturization compared to commercial photodetectors. This review paper focuses on the significant role of nanomaterials in infrared detection, an area critical for enhancing night vision and health monitoring technologies. The latest advancements in IR photodetectors that employ various nanomaterials and their hybrids are discussed. The manuscript covers the operational mechanisms, device designing, performance optimization strategies, and material challenges. This review aims to provide a comprehensive overview of the current developments in nanomaterial‐based IR photodetectors and to identify key directions for future research and technological advancements. [ABSTRACT FROM AUTHOR]

Low-symmetry two-dimensional (2D) materials have attracted significant attention for polarization-sensitive photodetection due to the optoelectronic anisotropy. Here, we demonstrated the strong in-plane anisotropy of In2Te5 through electron density distribution calculations based on density functional theory and developed a polarization-sensitive photodetector. The photodetector shows a responsivity of 171.16 mA/W and a response time of 0.42 s under visible light illumination. Additionally, it presents a polarization-sensitive photoresponse with a dichroic ratio of 1.34. Our work reveals the anisotropic optoelectronic properties of In2Te5, potentially stimulating research interest in Group III-VI 2D materials (Pentatelluride M2Te5, M = Al, Ga, In, etc.). [ABSTRACT FROM AUTHOR]

2D Ruddlesden─Popper (RP) halide perovskites are attracting increasing research interest due to their enhanced stability compared to 3D perovskites. However, the quantum confinement effect of bulk organic spacers hinders the separation and transport of photo‐generated carriers. Here, a multiple aromatic ring spacer, 3‐benzothiophene methylammonium (BTMA), is developed for a new 2D RP perovskite. The BTMA spacer is demonstrated, with a significant dipole moment, can impair the influence of the quantum confinement effect, and the presence of S atoms or thiophene is favorable for enhancing the interaction between organic spacers and inorganic sheets, improving the stability of perovskites. The perovskite photodetector with BTMA as spacers displays higher device performance than the control sample with 1‐naphthalene methylammonium (NMA) as spacers. Importantly, the outstanding stability of BTMA‐based perovskite films and devices is also confirmed under moisture, heat, and illumination conditions. Combining the asymmetric coplanar nanogap electrode architecture, the photodetectors' enhanced responsivity, detectivity, and external quantum efficiency of 314 A W−1, 3.4 × 1013 Jones, and 865%, respectively, are demonstrated. Importantly, the nanogap photodetectors display promising self‐power characteristics, which makes them attractive for numerous energy‐efficient applications. The work highlights a new route toward developing high‐performance 2D RP perovskite‐based photodetectors with excellent long‐term stability. [ABSTRACT FROM AUTHOR]

Current commercial shortwave infrared (SWIR) photodetectors typically necessitate deep cooling to mitigate random fluctuations induced by carrier thermal excitation. Developing high‐sensitivity SWIR photodetectors operating at room temperature is imperative for reducing equipment size and operational expenses. Leveraging the channel depletion mechanism of 2D semiconductors holds promise in suppressing dark current. Another concern lies in the limited choice of infrared absorbing materials and the difficulty in flexibly adjusting the response wavelength region. Here, a high‐sensitive exceptionally low‐noise SWIR photodetector operated is reported at room temperature based on few‐layer WSe2/TCNQ molecules charge transfer complex. Experiments and Calculations results exhibit the low‐frequency (0.6 eV) SWIR absorption stems from the intermolecular charge transfer transition at the interface of heterojunctions. The hybrid photodetector can achieve response efficiently from visible to SWIR (0.6–1.6 µm) with a decent gain 7.7 × 104 and an ultralow dark current noise spectral density (Sn) 1.95 × 10−16 A/Hz0.5 under a channel deplete state at room temperature. The peak specific detectivity is 2.5 × 1013 Jones at 0.7 µm and 7.4 × 1012 Jones at 1.2 µm, (Vgs = 80 V). This work has opened up a new pathway for the development of high‐sensitivity SWIR photodetectors at room temperature. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV), visible, and near‐infrared (NIR) broadband organic photodetectors are fabricated by sequential solution‐based thin film coatings of a polymer electron blocking layer (EBL) and a polymer photoactive layer. To avoid damage to a preceding polymer EBL during a subsequent solution‐based film coating of a polymer photoactive layer due to lack of solvent orthogonality, 2‐(((4‐azido‐2,3,5,6‐tetrafluorobenzoyl)oxy)methyl)−2‐ethylpropane‐1,3‐diyl bis(4‐azido‐2,3,5,6‐tetrafluorobenzoate) (FPA‐3F) is used as a novel organic cross‐linking agent activated by UV irradiation with a wavelength of 254 nm. Solution‐processed poly[N,N′‐bis(4‐butylphenyl)‐N,N′‐bis(phenyl)‐benzidine] (poly‐TPD) films, which are cross‐linked with a FPA‐3F photocrosslinker, are used for a preceding polymer EBL. A ternary blend film composed of PTB7‐Th, COi8DFIC, and PC71BM is used as a NIR‐sensitive organic photoactive layer with strong photosensitivity in multispectral (UV–visible–NIR) wavelengths of 300–1,050 nm. Poly‐TPD films are successfully cross‐linked even with a very small amount of 1 wt% FPA‐3F. Small amounts of FPA‐3F have little detrimental effect on the electrical and optoelectronic properties of the cross‐linked poly‐TPD EBL. Finally, organic NIR photodetectors with a poly‐TPD EBL cross‐linked by the small addition of FPA‐3F (1 wt%) show the detectivity values higher than 1 × 1012 Jones for the entire UV–visible–NIR wavelengths from 300 nm to 1050 nm, and the maximum detectivity values of 1.41 × 1013 Jones and 8.90 × 1012 Jones at the NIR wavelengths of 900 and 1000 nm, respectively. [ABSTRACT FROM AUTHOR]

Two-dimensional Cs2Pb(SCN)2I2 perovskite has an ultra-small interlayer spacing, inducing a series of interesting semiconductor properties, such as efficient interlayer carrier transport as well as lower exciton binding energy compared to perovskites with long alkylammonium cations. The prepared Cs2Pb(SCN)2I2 photodetector achieves a high on/off ratio of 2.1 × 104 with a specific detectivity of 6.2 × 1011 jones to 450 nm visible light, and a high sensitivity of 2747 μC Gyair−1 cm−2 to X-rays. [ABSTRACT FROM AUTHOR]

Inorganic semiconductor‐based nano/micro‐membranes are of great interest and can be used as active materials for high‐performance and flexible electronics, due to their unique and stable physical or chemical properties. However, the creation of high‐quality and single‐crystalline semiconducting membranes, particularly germanium (Ge) membranes, remains a significant challenge. In this study, a wet etching approach is developed to thin bulk Ge into soft Ge membranes, which are further used to fabricate flexible and stretchable photodetectors. The thickness of the obtained Ge membranes can be precisely controlled, with a minimum thickness of ≈1.6 µm. Investigations on the surface morphology, surface chemical composition, and Raman shifts indicate that the prepared Ge membranes are single‐crystalline and suitable for the following device fabrication. As an example, flexible and stretchable Ge photodetectors, of which the stretchability is realized by a meshed‐structure design, are demonstrated. Bending (with a minimum radius of 4 mm and a bending cycle of 10 000 times) and stretching (with a stretching strain of up to 10%) tests result in negligible variations in the device performance, revealing good flexibility, and stretchability, as well as the significant potentials of the prepared Ge membranes as candidates for flexible electronics. [ABSTRACT FROM AUTHOR]

Laboratory measurements of reflectance spectra of rocks and minerals at multiple viewing geometries are important for interpreting spacecraft data of planetary surfaces. However, efficiently acquiring such measurements is challenging, as it requires a custom goniometer that can accommodate multiple, bulky samples beneath a movable light source and detector. Most spectrogoniometric laboratory work to date has focused on mineral mixtures and particulates, yet it is also critical to characterize natural rock surfaces to understand the influence of texture and alteration. We designed the Three‐Axis N‐sample Automated Goniometer for Evaluating Reflectance (TANAGER) specifically to rapidly acquire spectra of natural rock surfaces across the full scattering hemisphere. TANAGER has its light source and the spectrometer's fiber optic mounted on rotating and tilting arcs, with a rotating azimuth stage and six‐position sample tray, all of which are fully motorized and integrated with a Malvern PanAnalytical ASD FieldSpec4 Hi‐Res reflectance spectrometer. Using well‐characterized color calibration targets, we have validated the accuracy and repeatability of TANAGER spectra. We also confirm that the system introduces no discernible noise or artifacts. All design schematics and control software for TANAGER are open‐source and available for use and modification by the larger scientific community. Plain Language Summary: To interpret spacecraft data sets of planetary surfaces, it is important to have similar data sets of rocks and minerals from Earth for comparison. Reflectance spectroscopy is a common technique in planetary science, and spacecraft make spectral reflectance measurements at multiple viewing geometries (with different positions of the sun relative to the planet's surface); therefore, it is important for laboratory spectral reflectance measurements to use multiple viewing geometries as well. However, such measurements are difficult, as they require custom instrumentation (a "goniometer") to control the angles of the light source and spectrometer detector. Most goniometers are designed for measuring small quantities of grains and particulates, but we have designed a new goniometer specifically for measuring the surfaces of bulky, natural rocks: the Three‐Axis N‐sample Automated Goniometer for Evaluating Reflectance (TANAGER). Using motorized, rotating and tilting arcs, TANAGER allows us to rapidly acquire reflectance spectra for multiple samples across a full range of viewing geometries. We have validated the accuracy and repeatability of TANAGER data, and we confirm that the system introduces no discernible noise or artifacts. All design schematics and control software for TANAGER are open‐source and available for use and modification by the larger scientific community. Key Points: Three‐Axis N‐sample Automated Goniometer for Evaluating Reflectance (TANAGER) is an automated goniometer designed to rapidly acquire reflectance spectra of rock surfaces across the full scattering hemisphereWe validated the accuracy and repeatability of TANAGER spectra and confirm that the system introduces no discernible noise or artifactsTANAGER's design schematics and control software are open‐source and available for use and modification by the scientific community [ABSTRACT FROM AUTHOR]

The authors aim to build a theoretical system for calibrating the position detection of a single quadrant photodiode (QPD) attached to 2D rotators and to suppress noise using a Sugeno‐type fuzzy inference system. According to the results, if the original ANFIS network (NWo) is trained under the conditions of resolution (rso), traing samples (No), and the possibility of random noise (po) and presented as {original, rso, No, po}, with the #X testing case presented as {case #X, rsx, Nx, px}, case #X is expected to be the all‐pass case of the two root‐mean‐squared error criteria under the conditions of rsx ≥ rso and px ≤ po. Thus, the measurement accuracy is improved without tracking historical data. Furthermore, the two conditions indicate the limitations of the proposed ANFIS‐based method. These conditions can be employed to save time and money. If a company produces many types of QPD rotators with different values of rs, the engineers can optimise the design to train the ANFIS network with only one case with the smallest rs and a larger p for all types of QPD rotators with any value of rs and p. This demonstrates the potential industrial application of the proposed method. The cover image is based on the Article ANFIS‐based controlled spherical rotator with quadrant photodiode to improve position detection accuracy by Bing‐Yuh Lu et al., https://doi.org/10.1049/ote2.12127. [ABSTRACT FROM AUTHOR]

Detecting extremely low light signals is the basis of many scientific experiments and measurement techniques. For many years, a high-voltage photomultiplier has been the only practical device used in the visible and infrared spectral range. However, such a solution is subject to several inconveniences, including high production costs, the requirements of a supply voltage of several hundred volts, and a high susceptibility to mechanical damage. This paper presents two detection systems based on avalanche photodiodes, one cooled and the second operating at room temperature, in terms of their potential application in thermoluminescent dosimeter units. The results show that the detection system with an uncooled photodiode may successfully replace the photomultiplier tube commonly used in practice. [ABSTRACT FROM AUTHOR]