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The investigation of the highest surface temperature and damage region of silicon-based photodiodes (PIN) was conducted through irradiation with millisecond (ms) pulse lasers. The convex spots on the surface of the biased photodiode were observed to be diminished by a millisecond pulse laser for the first time. The experimental results presented herein demonstrate the presence of a bump, even in cases where the maximum surface temperature of the damaged area does not exceed the melting point. The mechanism underlying this phenomenon was elucidated through the integration of simulation and experimentation in our study. The irradiation of silicon-based semiconductor detectors with lasers generates internal Joule heat, causing the temperature at the junction depth to initially reach the melting point. The expansion resulting from the Si phase transition induces outward pressure on Si3N4, leading to the eventual formation of a convex morphology. The findings of our study present a novel approach to enhance the security of photodetectors. [ABSTRACT FROM AUTHOR]

A validated method based on Haidinger fringes has been proposed to measure the optical constants for thin-walled glass cells. The method can significantly enhance measurement accuracy by utilizing the reflected spectrum to determine the optical constants of the sample. The reflected light off the inner and the outer surfaces of the cell combined together and formed the interferential pattern (Haidinger fringes) detected by the photodiodes. Taking into account that the sample in our experiment is a sealed cell, we deliberately set the incident angle to a non-zero value. First, the measurement principle has been analyzed, and subsequently, the relevant experimental platform has been established. To reduce random errors, we recalibrated the relationship between the frequency of the laser and the operating temperature. Furthermore, the incident angle has been accurately estimated using the method of non-linear least squares. Finally, the weighted average, considering correlated uncertainties for all measurements, is 1.873 ± 0.005 016 mm, which showcases clear advantages over conventional mechanical methods that risk potential damages. [ABSTRACT FROM AUTHOR]

The photovoltaic signal is an important characteristic of photodetectors, including but not limited to those that are based on p–n or p–i–n photodiodes. In an open-circuit configuration, pulsed excitation of the detector with ultrafast (femto or nanosecond) pulses leads to a photovoltaic signal that decays slowly (micro-second time scale). If the physics in the detector is dominated by the recombination of the photo-excited charge carriers, one expects the signal to decay without changing its sign. However, some experiments using short-pulse excitation have found that photovoltaic signals can undergo a sign change as a function of time following excitation, with positive signals immediately following the excitation, turning to negative signals several microseconds later. Here, we study various physical effects (density, temperature, electrostriction, pressure, photostriction, and bandgap renormalization) and determine their effect on photovoltaic signals. If, following ultrafast excitation, the carrier density and temperature are increased, and during relaxation the system reaches a state sufficiently close to the quasi-thermal equilibrium in which the carrier density is still elevated, but smaller than the intrinsic thermal equilibrium density at the elevated temperature, then the signal can become negative. [ABSTRACT FROM AUTHOR]

Tremendous research efforts are developed to suppress the reverse dark current (Jd) and enhance the responsivity of organic photodiodes (OPDs). The functional layers of traditional OPDs usually follow the principle of energy level alignment to make unobstructed photo‐carriers transport under reverse bias, but this inevitably leads to a large forward Jd. Herein, a universal strategy is proposed to manipulate the carrier dynamics and effectively suppress the forward Jd of OPDs, that is, tuning the energy level and electron traps of the anode interface layers (AILs). The bandgap and electron traps of typical organometallic chelate AIL (PEIE‐Co) can be well controlled by adjusting the component ratio of PEIE and metal ions. The wide bandgap increases the carrier injection barrier under reverse and forward bias, endowing OPD with a much lower Jd; the electron traps induce hole tunneling injection by capturing photo‐generated electrons under forward bias, thereby enabling the photomultiplication effect. The obtained OPD exhibits photoconductive/photomultiplication working mode at reverse/forward bias and the specific detectivity approaches ≈1013/1012 Jones, showing promise for adaptively detecting faint and strong light. This study presents an intelligent strategy to achieve dual‐mode OPDs, paving the way for the multifunctional development of photodetectors. [ABSTRACT FROM AUTHOR]

Iron tris(8-hydroxyquinoline) (Feq3) is thermally stable up to 310 °C. Feq3 thin films are used to fabricate Al/Feq3/p-Si/Al heterojunction diode. Based on the thermal properties, the device is annealed at 210 and 280 °C. In order to understand the diode behavior, as-deposited and annealed films are characterized by X-ray diffraction, transmission electron microscope and spectrophotometric measurements of transmittance. Annealing is found to influence the optical band gap of the films. The current–voltage (I–V) characteristics were measured for as-fabricated and annealed temperatures in dark and under illumination. The dark electrical parameters of diode are investigated, from which the ideality factor (n), potential barrier height (ϕ) and series resistance (Rs) of the as-fabricated and annealed Al/Feq3/p-Si/Al heterojunction are determined. These diode parameters are estimated and discussed in terms of both conventional I–V characteristics and Cheung–Cheung functions. The diode under illumination is found to be influenced by annealing and is found to have photoconduction characteristics in which the photoresponsivity (at − 1 V) of as-fabricated and annealed diode at 280 °C are estimated as 2.77 × 10–4 and 2.55 × 10–3 A/W, respectively. [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]

C14‐alkoxy/alkyl PBTTT‐OR‐R, a derivative of the prototype PBTTT polymer, is relevant for optoelectronic applications because it combines PBTTT‐like intercalation behavior with enhanced charge‐transfer absorption at longer wavelengths. Additionally, fundamental insights are achieved by comparing this alternating conjugated polymer in the presence and absence of homocoupling defects. While the homocoupling‐free oxidative variant, PBTTT‐OR‐R(O), as well as the Stille polymer with 19% homocoupling defects, PBTTT‐OR‐R(S), can both form co‐crystals when stoichiometrically mixed with PC61BM, the co‐crystal of the latter shows properties which are highly dependent on the thermal processing conditions because of the presence of these defects. The PBTTT‐OR‐R(S):PC61BM co‐crystal shows a low thermal stability and PC61BM can progressively be expelled upon heating. In cooling from the melt and depending on the cooling rate, mixtures of PBTTT‐OR‐R(S) and PC61BM show a competition between co‐crystallization (fast cooling) and separate crystallization (slow cooling). The PBTTT‐OR‐R(O):PC61BM co‐crystal is much more stable up to at least 260 °C and is not influenced by the applied cooling rate. These findings also translate to the device level. The performance of PBTTT‐OR‐R:PC61BM photodiodes is severely deteriorated after isothermal annealing in case of PBTTT‐OR‐R(S), whereas the thermally robust co‐crystals of PBTTT‐OR‐R(O) allow a more flexible design of optimized devices. [ABSTRACT FROM AUTHOR]

Black germanium (Ge) exhibits exceptional light absorption, holding significant promise for optoelectronic applications. However, achieving self‐powered photodetection performance in black Ge is challenging due to its high surface recombination rate. Herein, this challenge is addressed by demonstrating self‐powered Graphene (Gr)/black‐Ge Schottky photodiodes, achieved through simultaneous nanotexturing and high‐quality self‐passivation. This approach involves utilizing reactive ion etching with Cl2 and BCl3 to achieve Cl‐passivated black Ge. Optical analysis reveals excellent optical characteristics in both Cl2‐treated and BCl3‐treated samples, including a high aspect ratio of 1.9 and a low reflectance of 1.5%. Notably, the Cl2‐treated black Ge exhibits a higher carrier lifetime of 20.4 µs compared to the 11.7 µs lifetime of the BCl3‐treated black Ge, attributed to the self‐passivation induced by Cl2 plasma, effectively mitigating defects. Surface composition analysis further confirms the substantial role of Cl in passivation. Significantly, these improved properties translate into notable advancements in device performance, including an enhancement in responsivity from 21 to 276 mA W−1 when compared to planar Gr/Ge devices. These findings underscore the potential of Cl2 RIE for developing high‐performance Ge‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

The well-known Rule07 is a simple thus efficient way to compare available technologies for IR imaging detectors in terms of dark current. The noise is then often estimated using a shot noise approximation on the dark current. Both II–VI and III–V communities use this rule of thumb as a reference for well-performing IR photodiodes. For HOT applications, a dark current close to this rule07 is considered a necessary condition but not a sufficient one to obtain a high-performance IR imager. Indeed, when limited by shot noise, rule07 describes well the noise behavior of the considered device. However, when considering low-frequency noise, it fails to describe the expected performances. In this paper, we focus on another figure-of-merit, dedicated to detector low-frequency noise rather than dark current. Systemic 1/f noise investigation in an IR detector was first reported by Tobin et al. in 1980. There is today a relative consensus on the fact that measured 1/f noise is proportional to the dark current. The ratio between the amplitude of the 1/f noise and the dark current of the same devices may therefore be used as a figure-of-merit for a given technology. This ratio (called the Tobin factor α T ) therefore appears adequate to compare different technologies as a figure-of-merit qualifying 1/f noise properties. This dimensionless ratio can also be very useful for optimizing a particular technology or process. However, in order to be relevant, this figure-of-merit must be estimated carefully as it appears, for instance, pixel pitch-dependent. Different examples of Tobin coefficient extraction are presented in this paper. We show that, depending on the technologies, the values of the Tobin coefficient can spread over several orders of magnitude. However, only low values result in high-quality IR imagers. Today, the best results we obtained show that α T = 10 - 5 is a state-of-art value to be compared with. [ABSTRACT FROM AUTHOR]

Optoelectronic devices based on geometrically asymmetric architecture have recently attracted attention due to their high performance as photodetectors and simple fabrication process. Herein, a p‐type 2D MoSe2 photodetector based on geometrically asymmetric contacts is reported for the first time. The device exhibits a high current rectification ratio of ≈104 and a large self‐powered photovoltage responsivity of ≈4.38 × 107 V W−1, as well as a maximum photocurrent responsivity of ≈430 mA W−1 along with a response time of ≈2.3 ms under 470 nm wavelength at 3 V bias voltage. The photocurrent responsivity is further enhanced to an ultrahigh responsivity of ≈1615 mA W−1 by applying a gate bias voltage due to the electrostatic modulation of carrier concentration in the MoSe2 channel. The simple fabrication process of the geometrically asymmetric MoSe2 diodes along with their high photodetection and diode rectifying performance make them excellent candidates for electronic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid halide perovskites have emerged as the most promising optoelectronic materials for next‐generation solution‐processed devices, primarily attributed to their distinctive properties such as cost‐effectiveness, facile fabrication process, high light absorption coefficient, tunable bandgap, and relatively high charge carrier mobility. Nevertheless, the presence of Pb elements is inevitable in most high‐performance perovskite optoelectronic devices, posing environmental pollution concerns and impeding their commercialization. In this study, two novel non‐toxic bismuth‐ and antimony‐based perovskite materials with environmentally conscious approaches are developed. Their structures and optoelectronic properties have been systematically characterized. Subsequently, photoconductive‐ and photodiode‐type photodetectors are designed and fabricated. Notably, the photodiode configuration exhibits exceptionally low dark current and noise, superior detection sensitivity, fast response speed, and good device stability. Owing to these superior performance metrics, the devices demonstrate great potential for real applications. Furthermore, this study furnishes a theoretical framework and design perspectives for the solution‐processed semiconductor materials. [ABSTRACT FROM AUTHOR]

A thin magnesium oxide (MgO) layer was inserted at the i-NiO/n-Si interface of p -NiO/i-NiO/n-Si (p-i-n) photodiodes (PDs) to enhance the photo-to-dark current ratio of the prepared ultraviolet (UV) PDs. Both types of p-i-n PDs (with and without the MgO layer) exhibited clear rectifying behaviours. However, the p-i-n PDs with MgO insertion demonstrated an ideality factor (5.3) smaller than that of the p-i-n PDs without MgO (13.9), suggesting that MgO passivated the interface defects between NiO and Si. The p-i-n PDs with the MgO layer exhibited a lower dark current at a low reverse-bias voltage because carriers were blocked by the insulating MgO layer. However, the photo-generated carriers penetrated the thin MgO layer at high reverse-bias voltages. Therefore, the photo-to-dark current ratio was high at both low and high bias voltages. The p-i-n PDs with MgO have a higher photo-to-dark current ratio of approximately 12 times that of p-i-n PDs without MgO at 1-V reverse bias voltage. The detectivity of p-i-n PDs with MgO increased with bias voltage, reaching a peak value of 9.2 x 1013 Jones at a reverse-bias voltage of 8 V. However, the detectivity of the p-i-n PDs without MgO was approximately nine times lower and less dependent on the bias voltage. Carrier transport mechanism showed that at a small forward bias voltage, both the p-i-n PDs exhibited Ohmic conduction. The p-i-n PDs without MgO exhibited a diffusion-recombination model at a high forward bias voltage. In contrast, in the p-i-n PDs with the MgO layer, a space-charge-limited current dominated carrier transport. [ABSTRACT FROM AUTHOR]

This research presents a detailed methodology for indoor positioning using visible light communication (VLC) technology, focusing on overcoming the limitations of traditional satellite-based navigation systems. The system is based on an optical positioning framework that integrates trilateration techniques with a semi-spherical array of photodiodes, designed to enhance both positional accuracy and orientation estimation. The system effectively estimates the receiver's position and orientation with high precision by utilizing multiple white-light-emitting diodes (LEDs) as transmitters and leveraging angular diversity. The proposed method achieves an average position error of less than 3 cm and an angular accuracy within 10 degrees, demonstrating its robustness even in environments with obstructed line of sight. These results highlight the system's potential for significant indoor positioning accuracy and reliability improvements. [ABSTRACT FROM AUTHOR]

An array of compact, high-bandwidth (>200 MHz) and low-cost optical photodiodes has been developed and implemented on the PHASe MApping (PHASMA) experiment. Using purpose-built electronics, an array of 16 photodetectors was constructed and used to monitor broadband (1–5 MHz) fluctuations in light intensity emitted by flux ropes undergoing electron-only magnetic reconnection. These measurements reveal a swath of oscillatory behavior, including wave propagation inward toward the diffusion region at approximately the local electron Alfvén speed. Custom 3D-printed collection optics and mounting hardware allow quick reconfiguration of the array for radial or axial measurements. The electronics design is flexible enough to be used with other current-sourcing transducers, such as avalanche photodiodes; silicon photomultipliers; and infrared, x-ray, and UV photodiodes. A noise-rejecting electrical layout allows for low-noise operation close to pulsed plasma discharges. A 16-channel, 64-pixel tomographic array was constructed and initial reconstructions are presented. [ABSTRACT FROM AUTHOR]

This research presents a frequency reconfigurable antenna analysis for wireless applications using multiple light sources. The antenna is constructed on a Roger substrate with (44×28) mm2 dimensions. The antenna comprises two parallel tuner arrangements in addition to a V-shaped radiating section. Two optical PIN photodiodes are connected to the two parallel monopole tuners, which serve as the antenna's switching component and are utilized to adjust the resonant frequency. These two PIN photodiode switches work in the 600-1050 nm wavelength range. To analyze the antenna performance, four different optical sources are used. They are white colour LED lamp, 650 nm optical fiber, red LEDs, and IR LEDs. In every case, the antenna performance analysis is carried out for all the four logic states of the switches (00, 01, 10, 11). Under white lamp test conditions, the antenna's maximum gain is 6 dBi, and when red LEDs are employed as the optical source, its maximum bandwidth is 21%. The antenna reconfigurable frequencies are 3.5 GHz and 5-5.8 GHz (5, 5.2, 5.5, 5.8 GHz). [ABSTRACT FROM AUTHOR]

CdS, CdTe, Hg0.1Cd0.9Te, CdTe, and Ag films were progressively electrodeposited on ITO-coated soda–lime glass to manufacture a short- and mid-wavelength infrared photodetector. A distinctive feature of the applied electrodeposition method is the use of a non-aqueous solution containing ethylene glycol (EG) as the electrolyte in a traditional three-electrode configuration for every film deposition. Using EG as a supplementary electrolyte and using the same deposition conditions with a potential below 0.75 V for all film coatings reduces their environmental incompatibility and offers a low-cost and low-energy route for fabricating the reported photodetector. The produced photodetector has a sensitivity of up to ≈957 nm with a detectivity (D*) of 2.86 × 1012 cm Hz1/2 W−1 and a dark current density (Jdark) of 10−6 mA cm−2. Furthermore, the manufactured photodiode exhibits self-powered performance because Voc and Jsc are self-generated, unlike previously reported photodiodes. The presented all-layer electrodeposition assembly approach can easily be adapted to fabricate sensing devices for different applications. [ABSTRACT FROM AUTHOR]

In this research, the impact of the different zinc (Zn) concentrations on the physical and optoelectronic properties of Bi2S3 nanorods as self‐powered and photodiode applications was investigated. The performance of P‐N junction photodiodes has been for decades since they are crucial in energy applications. The structure, degree of crystallinity, and shape of Zn‐doped Bi2S3 nanorods of various doping percentages formed onto the indium tin oxide (ITO) substrates by the dip coating technique are investigated using X‐ray powder diffraction (XRD) and SEM. With increasing illumination time, the current–voltage (I–V) graphs demonstrate a rise in photocurrent. The diode's idealist factor was estimated using the I–V technique under 30 min of light illumination. [ABSTRACT FROM AUTHOR]

Abstract 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.

Although enhanced performance of photovoltaic devices by embedding metal nanoparticles in charge transport layer, doping into active layer bulk, decorating the active layer surface, and inserting at the interface between semiconductor and the electrode were reported, the effect of incorporating metal NPs at the interface of single crystal semiconductor and perovskite is rarely tackled. Herein the effects of incorporating Ag nanoparticals (AgNPs) at p-Si/MAPbI3 perovskite interface on the photodiode performance were investigated. The results showed that compared with the reference device (without AgNPs) the photoresponsivity of the device incorporating AgNPs is greatly improved with the exception of light with wavelengths falling in the spectral range where AgNPs have strong optical absorption. This effect is extremely significant for relatively shorter wavelengths in the visible region, and a maximal improvement of around 10.6 times in photoresponsivity was achieved. The physical origin of the exception for spectral range that AgNPs have strong optical absorption is the cancelation of scatter resulted enhancement through AgNPs by band-to-band absorption resulted reduction of photocurrent, in which the generated electron has energy near the fermi level and the hole has large effective mass, which relax by nonradiative recombination, thus making not contribution to the photocurrent. More importantly, the AgNP decorated device showed much faster photo response speed than the reference device, and a maximal improvement of around 7.9 times in rise and fall time was achieved. These findings provide a novel approach for high responsive and high speed detection for weak light. [ABSTRACT FROM AUTHOR]

The rapidly evolving communication field demands higher data capacity, faster transmission speeds, and improved anti-interference capabilities. However, the physical limitations of silicon-based photonics technology hinder the realization of photodetectors and other active devices. The discovery of two-dimensional (2D) materials, such as graphene, has opened promising opportunities for on-chip photodetection, showcasing distinctive physical and chemical properties and ultrathin nature. In this review, we first describe several representative 2D materials, including graphene, black phosphorus, and transition metal dichalcogenides (TMDCs). These materials offer diverse band structures and properties, presenting a plethora of options for varied applications. Then we highlight the utilization of these 2D materials in the development of high-performance photodetection devices, including photodiodes, field-effect transistors, and photodetectors. Furthermore, we delve into the practical applications of photodetectors, including room-temperature imaging, visual sensors, spectrometers, ranging, and other optoelectronic integrated systems. These real-world applications vividly demonstrate the versatility and potential of 2D materials across diverse fields. Overall, the unique structures and properties of 2D materials offer new possibilities for applications across various domains. Future research should be devoted to further explore the properties and applications of 2D materials to advance their development in the field of science and technology. [ABSTRACT FROM AUTHOR]

The field of compact optical microcavities has received significant research in the past decades, and a broad range of cavity‐based micromechanical sensors has been demonstrated. The present approach replaces the frequently employed, complex etched cantilever and membrane structures with a simple thin‐film system based on a compressible photonic microcavity to achieve pressure‐sensitive wavelength shifting of resonant modes. The effects of a topological dielectric mirror architecture on the light propagation in the system are extensively investigated. Topologically improved light‐matter interaction is experimentally demonstrated for systems where thin‐film devices are mounted on one side of the photonic cavity due to mechanical constraints. Coupled topological states are examined under the aspect of mode splitting and exhibit advantageous splitting tunability compared to non‐topological systems. The findings are complemented by the proposal of a simple spectral evaluation method allowing significant improvement in the precision of integrated Fabry‐Pérot sensors. The readout concept of the presented sensor allows a scalable improvement of the measurement precision by evaluating the resonant‐mode order in the deformable cavity. The experimental results and conceptual advancements provide pathways for significant improvements addressing the efficiency of light‐matter interaction in Fabry‐Pérot cavities and the readout precision of sensors incorporating thin‐film photodiodes in multimode photonic cavities. [ABSTRACT FROM AUTHOR]

Homojunctions are key elements in many mainstream electronic devices. However, conventional dopant‐based "pn" homojunctions are not easily achievable in new material families, such as the 2D materials. Several recent 2D material studies have shown that lateral pn homojunctions can instead be electrostatically induced using back gates localized to either the source or drain contacts. Here, a hBN‐encapsulated black phosphorus dual‐gate device containing a lateral pn homojunction, whose orientation can be switched via application of back gate voltages, is demonstrated. Importantly, this study extends the state‐of‐the‐art for this architecture by characterizing the photoresponse under infrared (λ = 2.2 µm) illumination. It is shown that when biased to form a homojunction, the device exhibits the photovoltaic effect, resulting in a specific detectivity of 8.5 × 108 cm Hz1/2 W−1 at 77 K under short‐circuit conditions, and an open circuit photovoltage up to 175 mV at 77 K. Further, it is shown that the device can be operated in photoconductive mode, allowing a high responsivity of 0.55 A W−1. This device is thus highly reconfigurable as it can be switched between photovoltaic and photoconductive modes of operation to prioritize low noise and fast response or high responsivity. [ABSTRACT FROM AUTHOR]

When an electromagnetic (EM) wave propagates in a medium whose properties are varied abruptly in time, the wave experiences refractions and reflections known as time-refractions and time-reflections, both manifesting spectral translation as a consequence of the abrupt change of the medium and the conservation of momentum. However, while the time-refracted wave continues to propagate with the same wave-vector, the time-reflected wave propagates backward with a conjugate phase despite the lack of any spatial interface. Importantly, while time-refraction is always significant, observing time-reflection poses a major challenge – because it requires a large change in the medium occurring within a single cycle of the EM wave. For that reason, time-reflection of EM waves was observed only recently. Here, we present the observation of microwave pulses at the highest frequency ever observed (0.59 GHz), and the experimental evidence of the phase-conjugation nature of time-reflected waves. Our experiments are carried out in a periodically-loaded microstrip line with optically-controlled picosecond-switchable photodiodes. Our system paves the way to the experimental realization of Photonic Time-Crystals at GHz frequencies. Time-reflected waves are a critical feature of time-crystals, yet their properties are historically difficult to measure. Here, the authors experimentally demonstrate time-reflected electromagnetic waves including direct evidence of their phase conjugate nature. [ABSTRACT FROM AUTHOR]

Light‐emitting diodes and photodiodes, often acting as transmitters and receivers, are two key optical components for constructing an optical communication system. Recently, solar‐blind optical wireless communication (SB‐OWC) has emerged as a promising free‐space communication platform due to its unique advantages, including low background noise, high security, and non‐line‐of‐sight ability. However, the development of deep ultraviolet (DUV) emitters and detectors is still in its early stages with relatively low efficiency and poor detection capability, which hampers the further progress of SB‐OWC. Herein, a triangular‐shaped micro‐sized diode (T‐μ‐diode) is reported that can significantly boost its DUV emission and detection performance compared with a regular circular‐shaped micro‐diode (C‐μ‐diode) due to improved current injection and enhanced light extraction/absorption behavior. Specifically, the T‐μ‐diodes demonstrate superior light output power with a −3 dB modulation bandwidth over 566 MHz operating at an extremely high current density of 2 kA cm−2 while possessing a higher photo‐responsivity of ≈160 mA W−1 with a faster response speed of 5.1 ns, surpassing the traditional C‐μ‐diodes in both light emitting and detecting modes. Importantly, a bidirectional on‐chip data transmission system is realized by simply switching the operation mode of two T‐μ‐diodes monolithically fabricated on the same platform with boosted emission and detection functionalities. [ABSTRACT FROM AUTHOR]

One of the characteristic features of PbTe is an uncommon growth of bandgap with increasing temperature, which is quite opposite to the bandgap behavior of the semiconductors commonly used in electronics, for example, Si, Ge, GaAs, and InSb. This specificity allows one to increase the operating temperature of photodiodes fabricated using PbTe up to about 150 K. At the first stage of development, we prepared infrared (IR) photodiodes on the base of bulk single crystalline PbTe. To this end, the ingots with a diameter of about 40 mm were grown by the Czochralski technique. Then, the PbTe p–n junctions were fabricated by using indium donor diffusion to diffuse indium into the PbTe samples. Current–voltage and capacitance–voltage characteristics and spectral detectivity were measured over a wide temperature range and analyzed. The dark saturation current density at T = 100 K was of the order of 10−7 A/cm2. Finally, the unique solid-state multi-stage thermoelectric cooler operated at temperatures up to 150 K was developed. The present study would pave the way to creating a module for efficient photodetection in the mid-wave IR range combining two solid-state devices, namely, the p–n photodiode and thermoelectric cooler, while the latter supports the former. [ABSTRACT FROM AUTHOR]

Phototransistors are three-terminal photodetectors that usually have a higher photocurrent gain than photodiodes due to the amplification of the gate electrode. In this work, a broad spectral phototransistor based on copper phthalocyanine (CuPc) and a Cs3Bi2I9 (CBI) heterojunction is fabricated by the full vacuum evaporation method. Due to the complementary UV–visible absorption of CuPc and CBI, the device exhibits superior performance under three different types of visible light illumination. The experimental results show that the structure of the organic/perovskite heterojunction active layer has the characteristics of good compatibility and a simple process. Meanwhile, by utilizing the superior light-absorption characteristics of perovskite materials and the strong exciton dissociation efficiency of a hetero-type heterojunction interface, the CuPc/CBI-PT exhibits a higher photoresponsivity, photosensitivity, specific detection rate, and lower operating voltage than the CuPc reference device. The stability test shows that the CuPc/CBI-PT can still obtain a 0.73 A/W photoresponsivity under 660 nm light illumination after being stored in the air for 360 h without any packaging. This indicates that the organic/perovskite heterojunction PT may be a good choice for the preparation of high-performance photodetectors. [ABSTRACT FROM AUTHOR]

In this study, the contact characteristics of graphene quantum dots (GQDs) formed on n‐type GaN semiconductors are investigated. Blue‐luminescent GQDs prepared using a hydrothermal method are sprayed onto a GaN wafer, and the electrical and optical properties of the fabricated contacts are investigated. The GQD/GaN contacts exhibit rectifying behavior with a typical Schottky barrier height of 0.64 eV. A metal–semiconductor–metal (MSM) photodiode with interdigitated GQD contacts on n‐type GaN is fabricated and provides an extremely low dark current. The spectral photoresponse of the GQD/GaN MSM photodiode includes a sharp increase in responsivity at wavelengths shorter than 375 nm. The responsivity of the MSM photodiode is remarkably improved with increasing the GQD reduction temperature (up to 800 °C), showing a good photoresponse in the ultraviolet region. [ABSTRACT FROM AUTHOR]

This paper proposes a new technique for a single-direction solar tracker. The proposed design is based on a sun sensor system that controls the position of the solar panel. The sun sensors of the proposed design contain four photodiodes that are placed on the solar panel in specific angles and directions. The proposed system has several advantages such as the simplicity of implementing the system. This system combines the real-time tracking of sunlight and the low cost of applying a single-direction tracker. The prototyping experiment and Simulink MATLAB were applied to show the advantages of applying a single-direction tracker by following the angle of sunlight during the day. Real-time sun position and irradiation data were applied. The experimental results show that the proposed single-axis sun sensor PV tracker system generates around 20 more electric power than a fixed-structure PV system. [ABSTRACT FROM AUTHOR]

Metal halide perovskite photodiodes have garnered extensive attention owing to their favorable optoelectronic properties, rendering them attractive for visible, near‐infrared, and X‐ray sensors. However, their predominant reliance on solution‐processing deposition techniques poses challenges for seamless integration into existing industrial processes. In this study, this limitation is addressed by developing fully vacuum‐processed perovskite photodiodes with varying hole transport layers (HTL). These findings underscore the critical role of HTL selection in influencing the dark and noise current characteristics of the diodes. With an optimized HTL, photodiodes are obtained with low noise current (≈3 10−14 A Hz−1/2) and high specific detectivity (≈1012 Jones at 710 nm at −0.5 V). The photodiodes are also tested as X‐ray detectors and are found to be stable under X‐ray radiation, with state‐of‐the‐art sensitivity of 33 ± 4 µC Gy−1 cm−2 and a low limit of detection of 2.0 ± 1.6 µG s−1. These insights contribute to the development of perovskite photodiodes with improved performance and broader industrial applicability. [ABSTRACT FROM AUTHOR]

The paper proposes the technology of silicon p-i-n mesa-photodiodes, which allows to exclude one high-temperature operation from the technological route. Reducing the number of thermal operations reduces the degree of degradation of the electro-physical characteristics of silicon during heat treatment, which also contributes to reducing the density of surface states at the SiSiO2 interface. It is proposed to etch the mesa-profile by the method of chemical-dynamic polishing using a gold masking coating. The obtained photodiodes are cheaper than serial samples made by diffusion-planar technology and have higher sensitivity. [ABSTRACT FROM AUTHOR]

The photoelectric properties of n-GaAs – p-(GaAs)1–x–y(Ge2)x(ZnSe)y heterostructures have been investigated both in photodiode and photovoltaic modes. It has been revealed that the spectral dependence of the photocurrent covers a wide range of energy intervals, ranging from 1.07 eV to 3 eV. It has been demonstrated that as the temperature of the crystallization onset (Toc) increases, the peaks of the spectral dependencies of the photoelectromotive force (photo-EMF) shift towards shorter wavelengths. It has been observed that as the crystallization onset temperature (Toc) of the solid solution layer (GaAs)1–x–y(Ge2)x(ZnSe)y increases, the lifetime of photo carriers increases from 10-7 s at Toc=650°C to 5ꞏ10-5 s at Toc=730°C. It is demonstrated that the peaks of the intrinsic photoluminescence band shift towards shorter wavelengths with an increase in the temperature of the crystallization onset. Additionally, the study of the intrinsic spectral region of photoluminescence in samples across the thickness of the epitaxial layer confirms the variability of the obtained structures. [ABSTRACT FROM AUTHOR]

Process monitoring systems, e.g., systems based on photodiodes, could be used in laser-based powder bed fusion (PBF-LB/M) to measure various process parameters and process signatures to eventually allow for a local, detailed analysis of the produced parts. Here, simple statements only concerning the occurrence of defects in parts are sufficient in many cases, especially with respect to industrial application. Therefore, a pragmatic approach to rapidly infer the occurrence of defects and their types based on in situ data obtained by commercially available process monitoring systems is introduced. In this approach, a color distribution in form of a histogram is determined for each produced part using layer-wise screenshots of the visualized data provided by the monitoring software. Assessment of the histograms of AlSi10Mg samples, which were processed with different parameter combinations, revealed characteristics depending on the prevailing defect types. These characteristics enable the prediction of the occurring defect types without the necessity to apply conventional downstream testing methods, and thus, a straightforward separation of parts with good quality from defective components. Since the approach presented uses the data visualization of the monitoring software, it can be used even when direct access to the raw data is not provided by the machine manufacturer. [ABSTRACT FROM AUTHOR]

The resolution of Si complementary metal–oxide–semiconductor field-effect transistor (C-MOSFET) image sensors (CISs) has been intensively enhanced to follow the technological revolution of smartphones, AI devices, autonomous cars, robots, and drones, approaching the physical and material limits of a resolution increase in conventional Si CISs because of the low quantum efficiency (i.e., ~40%) and aperture ratio (i.e., ~60%). As a novel solution, a hybrid organic–Si image sensor was developed by implementing B, G, and R organic photodiodes on four n-MOSFETs for photocurrent sensing. Photosensitive organic donor and acceptor materials were designed with cost-effective small molecules, i.e., the B, G, and R donor and acceptor small molecules were Coumarin6 and C_60, DMQA and MePTC, and ZnPc and TiOPc, respectively. The output voltage sensing margins (i.e., photocurrent signal difference) of the hybrid organic–Si B, G, and R image sensor pixels presented results 17, 11, and 37% higher than those of conventional Si CISs. In addition, the hybrid organic–Si B, G, and R image sensor pixels could achieve an ideal aperture ratio (i.e., ~100%) compared with a Si CIS pixel using the backside illumination process (i.e., ~60%). Moreover, they may display a lower fabrication cost than image sensors because of the simple image sensor structure (i.e., hybrid organic–Si photodiode with four n-MOSFETs). [ABSTRACT FROM AUTHOR]

Perovskite semiconductors have achieved great success during the last decades in the application of solar cells, light-emitting diodes, and photodiodes. Developing strategies to pattern perovskites with high-resolution is crucial to broaden the application scenarios of perovskite displays and on-chip lighting. However, the widely used lithography procedure has the problem of high-cost and complexity. In this study, we demonstrate a method to pattern a luminescent perovskite-acrylic polymer composite that is prepared by direct injection at room temperature. This strategy uses standard photoresists and UV lithography at room temperature, and then the pattern in the photoresists can be easily transferred to the perovskite-acrylic polymer composite. Finally, we can obtain high-quality micron-scale features. Furthermore, we demonstrate the universality of this strategy by adapting perovskite with different color emissions into the composite and patterning it using the same procedure. Another advantage of this patternable perovskite-acrylic polymer composite is its superb water-repellent properties, which are believed to be of great potential in underwater applications. [ABSTRACT FROM AUTHOR]

Different approaches have been introduced to raise the response speed of bulk heterojunction‐based organic photodiodes (OPDs), with the best‐performing devices now having speeds in the MHz range. In most organic photodiodes, the response speed is commonly assumed to be due to transit time of charge carriers. Upon investigating fluence‐dependent photoresponse of different OPDs, it is found here that bimolecular recombination dictates the response speed at higher fluence levels. Herein, four different organic blend based photodiode systems and their response speed to a range of incident optical fluences are reported. A steep variation in response speed, depending upon the blend system is observed. Using experimental and theoretical studies, the intensity‐dependent response speeds are attributed to differences in the suppressed recombination factor. A high factor enables faster response times in the regime of higher light intensity. This new approach to high‐speed detections has implications for the design of high‐speed organic photodetectors, especially in applications where the speed of the photodetector is most important irrespective of the intensity of the incident signal. [ABSTRACT FROM AUTHOR]

Chalcogenide semiconductors have emerged as promising candidates for optoelectronic applications due to their unique properties, including low toxicity, fabrication cost, superior stability, and decent charge transport properties. In particular, Bi-based chalcogenides, e.g., AgBiS2 and Bi2S3, have been extensively studied for photovoltaic and photodetection applications. AgBiS2 exhibits relatively high photoconversion efficiency but large dark current. On the other hand, Bi2S3 possesses relatively low dark current but limited charge transport. In this study, we introduce zinc ion within the Bi2S3 precursor and fabricate phase-pure ZnBi2S4 semiconductor, which showed improved optoelectronic properties. The fundamental properties of ZnBi2S4 are fully characterized, and we also demonstrated photodiodes with excellent device performance, suggesting great potential for photodetection. [ABSTRACT FROM AUTHOR]

Underwater optical wireless communication (UOWC) has gained interest in recent years with the introduction of autonomous and remotely operated mobile systems in blue economic ventures such as offshore food production and energy generation. Here, we devised a model for estimating the received power distribution of diffused line-of-sight mobile optical links, accommodating irregular intensity distributions beyond the beam-spread angle of the emitter. We then used this model to conduct a spatial analysis investigating the parametric influence of the placement, orientation, and angular spread of photodiodes in array-based receivers on the mobile UOWC links in different Jerlov seawater types. It revealed that flat arrays were best for links where strict alignment could be maintained, whereas curved arrays performed better spatially but were not always optimal. Furthermore, utilizing two or more spectrally distinct wavelengths and more bandwidth-efficient modulation may be preferred for received-signal intensity-based localization and improving link range in clearer oceans, respectively. Considering the geometric implications of the array of receiver photodiodes for mobile UOWCs, we recommend the use of dynamically shape-shifting array geometries. [ABSTRACT FROM AUTHOR]

The cooling requirement for long-wave infrared detectors still creates significant limitations to their functionality. The phenomenon of minority-carrier exclusion and extraction in narrow-gap semiconductors has been intensively studied for over three decades and used to increase the operating temperatures of devices. Decreasing free carrier concentrations below equilibrium values by a stationary non-equilibrium depletion of the device absorber leads to a suppression of Auger generation. In this paper, we focus on analyzing exclusion and extraction effects separately, based on experimental and theoretical results for a HgCdTe photodiode. To carry out an experiment, the n+-P+-π-N+ heterostructure was grown by metal organic chemical vapor deposition on CdTe-buffered GaAs substrate. In order to separate the extraction and exclusive junctions, three different devices were evaluated: (1) a detector etched through the entire n+-P+-π-N+ heterostructure, (2) a detector made of the P+-π photoconductive junction and (3) a detector made of the π-N+ photodiode junction. For each device, the dark current density–voltage characteristics were measured at a high-temperature range, from 195 K to 300 K. Next, the carrier concentration distribution across the entire heterostructure and individual junctions was calculated using the APSYS simulation program. It was shown that when the n+-P+-π-N+ photodiode is reverse biased, the electron concentration in the π absorber drops below its thermal equilibrium value, due to the exclusion effect at the P+-π junction and the extraction effect at the π-N+ junction. To maintain the charge neutrality, the hole concentration is also reduced below the equilibrium value and reaches the absorber doping level (NA), leading to the Auger generation rate's reduction by a factor of 2ni/NA, where ni is the intrinsic carrier concentration. Our experiment conducted for three separate detectors showed that the exclusion P+-π photoconductive junction has the most significant effect on the Auger suppression—the majority of the hole concentration drops to the doping level not only at the P+-π interface but also deep inside the π absorber. [ABSTRACT FROM AUTHOR]

Silicene is a 2D monoatomic sheet of silicon and can be used for various applications such as degradation, therapy, and biosafety. Polyaniline (PANI) is a conducting polymer employed for electronic devices. In this study, we synthesized PANI–silicene composites and operated as an external interfacial layer between Al and different type substrates of p-Si and n-Si to compare Schottky-type photodiodes of PANI–silicene/n-Si and PANI–silicene/p-Si. The silicene structures were investigated using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques. Also, the light power intensity dependent of PANI–silicene/n-Si and PANI–silicene/p-Si photodiodes carried out in the range 0–100 mW/cm2 and I–t measurements utilized to determine the response time of the photodiodes. Basic parameters of devices such as ideality factors barrier, height, and series resistance were obtained by Norde and Cheung methods and thermionic emission (TE) theory from I–V graphs. While the PANI–silicene/n-Si exhibited high ideality factor values of 5.49, the PANI–silicene/p-Si photodiodes showed a low ideality factor of 1.48. The photodiode parameters such as detectivity and responsivity were calculated as 6.40 × 109 Jones and 38.9 mA/W for n-Si substrate and 78.2 mA/W and 8.81 × 109 Jones for p-Si substrate. The case of basic electrical properties for PANI–silicene composite interlayer-based photodiodes was analyzed in detail. [ABSTRACT FROM AUTHOR]

Selenium as one of the most historical semiconductors has been used for photovoltaics and photodetection, thanks to its excellent optoelectronic properties, superior stability, facile and low‐cost fabrication. However, commercialized Se‐based devices are mainly based on its amorphous state, which significantly limits the charge transport and requires relatively large bias voltage. The charge carrier dynamics of high‐performance crystalline Se thin films are barely reported, and related photodiodes have not been realized mainly limited by the large dark current and slow response speed. Here, poly‐crystalline Se thin films via vacuum evaporation, in situ thermal annealing, and engineered the interfaces with various metal electrodes are fabricated, which resulted in enhanced charge transport properties and reduced device leakage. The optimized Se photodiodes exhibited excellent performance metrics, including extremely low dark current density, decent specific detectivity, and superior stability. Furthermore, the optimized Se photodetectors are also introduced for single‐pixel imaging, which demonstrates excellent sensitivity and great potential for real applications. [ABSTRACT FROM AUTHOR]

In this study, a layer of isonicotinohydrazide and pyrene-based Schiff base (PyMIs) was formed on the front side of a p-Si semiconductor using the spin coating method, and an Al/PyMIs/p-Si/Al diode was fabricated. The I-V characteristics of the fabricated diode were measured under dark and from 20 to 100 mW/cm2 illumination intensities for both forward and reverse bias. Diode parameters, including saturation current (), ideality factor (n), and barrier height () were investigated for all measurements based on thermionic emission theory. The values n changed from 2.51 to 2.05, and the changed from 0.77 eV to 0.86 eV as light intensity increased from dark to 100 mW/cm2. The series resistance () values of the diode were investigated using the modified Norde's function and Cheung's functions. An analysis of the forward plot of Al/PyMIs/p-Si (MOmS)-type diode specified the carrier transport domination by ohmic conduction in the lower bias regions, by the space-charge-limited current (SCLC) at medium bias regions and the trap-charge limit current (TCLC) transport mechanism at higher bias regions. The fabricated diode exhibited typical photodiode behavior with reverse current values increasing from 9.13 × 10− 6 A to 1.05 × 10− 4 A, respectively. Furthermore, characteristics illuminated from 20 to 100 mW/cm2 were also studied, and they indicated that the Al/PyMIs/p-Si diode could operate in a photovoltaic regime. [ABSTRACT FROM AUTHOR]

We developed a flexible imager comprising low‐temperature polycrystalline silicon thin‐film transistors and organic photodiodes. The developed flexible imager has high‐resolution and high‐speed readout characteristics. Owing to these characteristics, pulse wave signals can be measured, and the images of fingerprints and veins can be obtained. Furthermore, we developed three‐axis tactile pressure sensors by integrating flexible optical components. The sensors can detect both normal and tangential pressures. [ABSTRACT FROM AUTHOR]

This work reports on the fabrication of ZnO polymer-based hybrid ultraviolet (UV) photodiodes with a configuration of ITO/ZnO-nanorod/F8BT/PEDOT:PSS/Ag. The diode was fabricated by spin-coating p-type F8BT and PEDOT:PSS polymers on hydrothermally grown n-type ZnO nanorods. The growth of ZnO nanorods was carried out by varying seed layer alcohols, viz., methanol, ethanol, isopropanol, and aqueous ethanol (70% alcohol). These solvents influenced the nanorod diameter, surface coverage, and surface defects. Herein, we demonstrate that the uniformity and defects in ZnO nanorods govern the electrical properties, photoresponse, and figures of merit of the photodiodes. In particular, the photodiodes are evaluated on their rectification ratio, ideality factor (η), responsivity (R), external quantum efficiency (EQE), and response time (Tdecay). The photodiode fabricated with ZnO nanorods grown on the methanol seeding layer has demonstrated the best performance, owing to the uniform surface coverage of the nanorods. It also presented the highest rectification ratio of ∼640, a Tdecay of 108 s, a η of 2, an EQE of ∼2760%, and an R of ∼8.14 A/W at −2 V. [ABSTRACT FROM AUTHOR]

The surface leakage in InAs/GaSb type-II superlattice (T2SL) is studied experimentally and theoretically for photodiodes with small sizes down to 10 × 10 μm2. The dependence of dark current density on mesa size is studied at 110 and 200 K, and surface leakage is shown to impact both generation–recombination (GR) and diffusion dark current mechanisms. A quasi-3-dimensional model to simulate the fabrication process using surface traps on the pixel's sidewall is presented and is used to accurately represent the dark current of large and small pixels with surface leakage in the different temperature regimes. The simulations confirmed that the surface leakage current has a GR and diffusion component at low and high temperature, respectively. Finally, the surface leakage current has been correlated with the change in minority carrier concentration at the surface due to the presence of donor traps. [ABSTRACT FROM AUTHOR]

The perovskite single crystals (PSC) produced by solution‐processed metallic ions doping have a thick p–n junction (greater than 10 µm). Meanwhile, to achieve high responsivity, the carrier drift length (µτE) has to be larger than the dimensions of the detector. If the p–n junction is quite thick, a high bias voltage is required. For the practical application of photodiode, it is imperative to find a means to generate a thin p–n junction. A productive technique is suggested for forming a thin p–n junction by diffusing metallic ions, resulting in a longer drift length of the carrier than the depletion width. Thinner p–n junction leads to reduced dark current density (0.5 µA cm−2), low trap density (5.71 × 108 cm−3), high mobility (417 cm2 V−1 s−1), and hence increased responsivity (77.69 A W−1) for 30 µW cm−2 UV illumination under a low applied voltage of −15 V. A quick response time with a rise/fall duration of 22 ms/30 ms under 0 V and long‐term stability for over 3 months in ambient airis achieved. To comprehend the performance with the thinner p–n junction‐based photodiodes, the results under UV–Vis illumination are examined and compared. The outcomes hint at a method that holds promise for producing efficient photodiodes. [ABSTRACT FROM AUTHOR]

In this study, we present a complex investigation for miniaturizing perovskite photodiodes (PPDs) in various geometries with the use of ultraviolet laser scribing (UV-LS). Employing a 355 nm (3.5 eV) pulsed laser at 30 kHz, we manufactured PPDs with pixel configurations of 70 × 130, 520 × 580, and 2000 × 2000 μm2. The utilization of UV-LS has a proven efficiency in achieving relevant diode characteristics, such as low dark currents and high shunt resistance, as well as ultrafast response. The multi-step scribing cycle provided precise patterning of PPDs in a string design. The dark current densities demonstrated exceptional uniformity, ranging from 10−10 A/cm2 for 2000 × 2000 μm2 pixelated PPDs to 10−9 A/cm2 for the 70 × 130 μm2 configuration. The string PPDs, consisting of 10 pixels per string, displayed homogenous dark current values, ensuring effective isolation between devices. Under green light illumination (540 nm), all PPD types exhibited a broad linear dynamic range (LDR). Specifically, LDR values reached 110, 117, and 136 dB for 70 × 130, 520 × 580, and 2000 × 2000 devices, respectively, spanning an illumination intensity range from 2 × 10−3 to 2 mW/cm2. High responsivity values up to 0.38 A/W, depending on the PPDs' geometry, highlight the potential of laser scribing devices for sensing in the visible range. The calculated specific detectivity performance (from 1011 to 1013 Jones) surpasses commercial analogs, while the sub-microsecond response of 70 × 130 and 520 × 580 μm2 miniaturized devices underscores their suitability for precise time resolution detection systems. [ABSTRACT FROM AUTHOR]

Poly(3,4‐ethylenedioxythiphene):poly(styrene sulfonate) (PEDOT:PSS) is widely used as hole transport layer in photodiodes due to its deep work function, flexibility, low cost, and commercialization potentials. However, organic photodetectors (OPDs) using commercial PEDOT:PSS (C‐PEDOT:PSS) interlayers usually suffer from high noise currents. Here, a simple dilution‐induced strategy is proposed for constructing an ultrathin self‐assembled PEDOD:PSS layer (D‐PEDOT:PSS). Dilution‐induced chain disentanglement leads to smaller grain sizes, which is beneficial to reduce defects and enhances selective charge transport. This enables the fabrication of near‐infrared PM6:Y6 organic photodetectors with three orders of magnitude lower ultra‐low dark current (<1.5×10−10 A cm−2) and one order of magnitude lower spectral‐noise density (2.1×10−14 A Hz−1/2) compared to devices using untreated PEDOT:PSS, at ‐0.1 V applied bias. With low dark current and enhanced responsivity, the shot‐noise‐limited detectivity increases by 35 times. An imaging system using OPDs as a sensing pixel has achieved high‐contrast images, demonstrating the imaging potential of the OPDs. The universality of this strategy to enhance the performance of OPDs is further demonstrated through three additional donor‐acceptor blends. This study presents a simple and effective strategy to reduce the noise current of PEDOT:PSS‐based OPDs and provides insights into the correlation between interfacial properties and the performance of OPDs. [ABSTRACT FROM AUTHOR]