Improvement Detecting Method of Optical Axes Parallelism of Shipboard Photoelectrical Theodolite Based on Image Processing

An improvement detecting method was proposed according to the disadvantages of testing method of optical axes parallelism of shipboard photoelectrical theodolite (short for theodolite) based on image processing. Pointolite replaced 0.2'' collimator to reduce the errors of crosshair images processing and improve the quality of image. What’s more, the high quality images could help to optimize the image processing method and the testing accuracy. The errors between the trial results interpreted by software and the results tested in dock were less than 10'', which indicated the improve method had some actual application values.

Significant photoelectrical response of epitaxial graphene grown on Si-terminated 6H-SiC

Photoelectrical response characteristics of epitaxial graphene （EG） films on Si- and C-terminated 6H-SiC, and transferred chemical vapor deposition （CVD） graphene films on Si-terminated 6H-SiC have been investigated. The results show that upon illumination by a xenon lamp, the photocurrent of EG grown on Si-terminated SiC significantly increases by 147.6%, while the photocurrents of EG grown on C-terminated SiC, and transferred CVD graphene on Si-terminated SiC slightly decrease by 0.5% and 2.7%, respectively. The interfacial buffer layer between EG and Si-terminated 6H-SiC is responsible for the significant photoelectrical response of EG. Its strong photoelectrical response makes it promising for optoelectronic applications.

Electric field and photoelectrical effect bi-enhanced hydrogen evolution reaction

Molybdenum disulfide （MoS2） is an earth-abundant and low-cost hydrogen evolving electrocatalyst with the potential to replace traditional noble metal catalysts. The catalytic activity can be significantly enhanced after modification due to higher conductivity and enriched active sites. However, the underlying mechanism of the influence of the resistance of electrode material and contact resistance on the hydrogen evolution reaction （HER） process is unclear. Herein, we present a systematic study to understand the relationship between HER performance and electrode conductivity, which is bi-tuned through the electric field and photoelectrical effect. It was found that the onset overpotential consistently decreased with the increase of electrode conductivity. In addition, the reduction of the contact resistance resulted in a quicker electrochemical reaction process than enhancing the conductivity of the MoS2 nanosheet. An onset overpotential of 89 mV was achieved under 60 mW/cm^2 sunlight illumination （0.6 sun） and a simultaneous gate voltage of 3 V. These physical strategies can also be applied to other catalysts, and offer new directions to improve HER catalytic performance of semiconductor materials.

Printed thin film transistors with 10^(8)on/off ratios and photoelectrical synergistic characteristics using isoindigo-based polymers-enriched(9,8)carbon nanotubes

Monochiral single-walled carbon nanotubes(SWCNTs)can enable high-performance carbon-based electronic devices and integrated circuits.However,their fabrication often requires complex SWCNT purification and enrichment.Herein,we showed that isoindigo-based polymer derivatives(PDPPIID and PFIID)directly enriched(9,8)nanotubes from as-synthesized SWCNT powders selectively and efficiently to yield high concentration(9,8)nanotube inks.The selective wrapping mechanism was elucidated by classical full-atomistic molecular dynamic(MD)simulations.Thin-film transistors(TFTs)were fabricated by depositing the SWCNT ink into device channels using aerosol jet printing.TFT performance was strongly influenced by polymer residues,the deposition condition(humidity),and ink concentration.Optimized TFTs showed excellent device-to-device uniformity with 108 on/off ratios.Further,optoelectronic transistors were fabricated,and their photoelectrical neuromorphic characteristics,storage,memory,and logic functions were characterized under the pulsed light and voltage stimulations,demonstrating excellent application potentials.

InGaZnO-based photoelectric synaptic devices for neuromorphic computing

Photoelectric synaptic devices could emulate synaptic behaviors utilizing photoelectric effects and offer promising prospects with their high-speed operation and low crosstalk. In this study, we introduced a novel InGaZnO-based photoelectric memristor. Under both electrical and optical stimulation, the device successfully emulated synaptic characteristics including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), long-term potentiation (LTP), and long-term depression (LTD). Furthermore, we demonstrated the practical application of our synaptic devices through the recognition of handwritten digits. The devices have successfully shown their ability to modulate synaptic weights effectively through light pulse stimulation, resulting in a recognition accuracy of up to 93.4%. The results illustrated the potential of IGZO-based memristors in neuromorphic computing, particularly their ability to simulate synaptic functionalities and contribute to image recognition tasks.

Pressure-Induced Structural Transition and Enhanced Photoelectric Properties of Tm_(2)S_(3)

Rare earth sesquisulfides have drawn growing attention in photoelectric applications because of their excellent electronic and photoelectric properties upon compression.We investigate the structural,electrical,and photoelectric properties of Tm_(2)S_(3) under high pressure through electrical impedance,UV-vis absorption,Raman spectroscopy,x-ray diffraction,and photoelectric measurements.It is found that δ-Tm_(2)S_(3) transforms into high-pressure𝛼-phase around 5GPa,accompanied by a substantial reduction in atomic distance,bandgap,and resistivity.Consequently,the photocurrent density and responsivity of Tm_(2)S_(3) exhibit dramatic increase behavior,achieving five orders of magnitude enhancement in α-phase compared with the initial δ-Tm_(2)S_(3).Moreover,α-phase maintains a high photocurrent responsivity of three orders of magnitude after unloading.This work demonstrates significant enhancement of the photoelectric properties of Tm_(2)S_(3) by applying pressure,which paves the way for improving the performance of future photoelectric devices.

Paths on breaking 20% efficiency of transport-layer-free perovskite solar cells

In the perovskite photovoltaic community, sandwiched device configurations such as n-type transport layer-perovskite-p-type transport layer (n-i-p, regular) or p-i-n (inverted) are research mainstreams for higher power conversion efficiencies (PCEs)[1].One of the important functions of these transport layers (TLs) is the construction of built-in-electric fields (BFs) for carrier directional diffusion [2].

Regulating Effect of Substrate Temperature on Sputteringgrown Ge/Si QDs under Low Ge Deposition

The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectroscopy,and photoluminescence(PL)tests.The experimental results indicate that temperatures higher than 750℃effectively increase the crystallization rate and surface smoothness of the Si buffer layer,and temperatures higher than 600℃significantly enhance the migration ability of Ge atoms,thus increasing the probability of Ge atoms meeting and nucleating to form QDs on Si buffer layer,but an excessively high temperature will cause the QDs to undergo an Ostwald ripening process and thus develop into super large islands.In addition,some PL peaks were observed in samples containing small-sized,high-density Ge QDs,the photoelectric properties reflected by these peaks were in good agreement with the corresponding structural characteristics of the grown QDs.Our results demonstrate the viability of preparing high-quality QDs by magnetron sputtering at high deposition rate,and the temperature effect is expected to work in conjunction with other controllable factors to further regulate QD growth,which paves an effective way for the industrial production of QDs that can be used in future devices.

Improved efficiency and stability of inverse perovskite solar cells via passivation cleaning

Amidst the global energy and environmental crisis,the quest for efficient solar energy utilization intensifies.Perovskite solar cells,with efficiencies over 26%and cost-effective production,are at the forefront of research.Yet,their stability remains a barrier to industrial application.This study introduces innovative strategies to enhance the stability of inverted perovskite solar cells.By bulk and surface passivation,defect density is reduced,followed by a"passivation cleaning"using Apacl amino acid salt and isopropyl alcohol to refine film surface quality.Employing X-ray diffraction(XRD),scanning electron microscope(SEM),and atomic force microscopy(AFM),we confirmed that this process effectively neutralizes surface defects and curbs non-radiative recombination,achieving 22.6%efficiency for perovskite solar cells with the composition Cs_(0.15)FA_(0.85)PbI_(3).Crucially,the stability of treated cells in long-term tests has been markedly enhanced,laying groundwork for industrial viability.

Rational design of photofunctional dyes BODIPYs/aza-BODIPYs and applications for photocatalysis, photoelectric conversion and thermochromic materials

4,4-Difluoro-4-bora-3a,4a-diaza-sindacene (BODIPY) is a sort of photofunctional dye which possesses advantages including strong light-capturing property, high photon-resistance, etc. Meso-N substituted aza-BODIPY is a crucial derivative of BODIPY scaffold that has the favorable optical properties and a significant spectral redshift. The photophysical properties can be tuned by molecular design, and the attenuation path of the excited state energy release of absorbed light energy can be well controlled via structural modifications, enabling tailored application. It has been extensively employed in life medicine fields including fluorescence imaging diagnosis, photodynamic therapy photosensitizer and photothermal therapy reagent and so forth. Extensive research and review have been performed in these areas. However, BODIPYs/aza-BODIPYs have a significant role in energy, catalysis, optoelectronics, photo-responsive materials and other fields. Nevertheless, there are relatively few studies and reviews in these fields on the modification and application based on BODIPY/aza-BODIPY scaffold. Herein, in this review we summarized the application of BODIPY/aza-BODIPY in the aforementioned fields, with the molecular regulation of dye as the foundation and the utilization in the above fields as the objective, in the intention of providing inspiration for the exploration of innovative BODIPY/aza-BODIPY research in the field of light resource conversion and functional materials.

Facile Preparation, Characterization of Flexible Organic Solar Cells Using P3HT-MWCNTS Composite Photoactive Layer

Multiwalled carbon nanotubes (MWCNTs) mixed in poly(3-hexylthiophene) (P3HT) were used as a photoactive layer for organic solar cells (OSC). The flexible OSCs of a structure of PET/rGO-P3HT/P3CT/PCBM/LiF-Al were prepared by spincoating. The UV-Vis absorption spectra of the photoactive films and current-voltage characteristics of the OSCs showed the advantage of the composite devices above the pristine-polymeric ones. Under illumination of light with a 100 mW/cm2-powerdensity, the photoelectrical conversion efficiency (PCE) of the OSCs with 3.0 wt% MWNCTs embedded in the photoactive layer possess a value as large as 2.35%. The obtained results suggest further useful applications of the flexible large-area solar cells.

Memristive Artificial Synapses for Neuromorphic Computing

Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary units.Mimicking synaptic functions with these devices is critical in neuromorphic systems.In the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic functions.In this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical signals.The working mechanisms of the devices are analyzed in detail.This is followed by a discussion of the progress in mimicking synaptic functions.In addition,existing application scenarios of various synaptic devices are outlined.Furthermore,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.

Performance evaluation and optimization design of photoelectric pyrometer detection optical system

The measurement and control of high temperature play very important roles in national defense,military,scientific experiments,industrial and agricultural production.Photoelectric pyrometer is one of the important radiation thermometers for non-contact temperature measurement.It has an important application in the field of high temperature measurement,and its performance directly affects the accuracy of temperature measurement.By improving the design of the detection optical system of the photoelectric pyrometer,the imaging performance of the photoelectric pyrometer can be improved effectively,and the temperature measurement accuracy can be improved.In this paper,the temperature measurement principle of photoelectric pyrometer,the wo rking principle of the detection optical system and the composition of the system are introduced.The optical components that affect the imaging of the optical system of the photoelectric pyrometer are analyzed.The optical pyrometer detection optical system is simulated by ZEMAX software,based on the analysis results,the Modulation Transfer Function(MTF)and the spot Diagram are used as the main evaluation criteria to optimize the design of the objective lens of the photoelectric pyrometer detection optical system.The imaging performance of the photoelectric pyrometer detection optical system and the accuracy of temperature measurement of the photoelectric pyrometer are improved by optimization design of the detection optical system.

Research progress in terahertz quantum-cascade lasers and quantum-well photodetectors

As semiconductor devices,the terahertz quantum-cascade laser is a coherent source based on intersubband transitions of unipolar carriers while the terahertz quantum-well photodetector is a kind of detector which matches the laser frequency.They are solid-state,electrically operated,and can be easily integrated with other components.This paper reviews the state of the art for the design,working performance,and future directions of the two devices.Their applications in photoelectric characterization and imaging are also discussed.

Preparation of polypyrrole/polyvinylalcohol(PPy/PVA)composite foam electrode material

Polypyrrole/polyvinylalcohol（PPy/PVA） foam was prepared by direct foam polymerization in water and then it was coated on the indium-tin oxide transparent conductive glass（ITO） to form conventional three-electrode cell.FTIR and UV-vis spectra were adopted to characterize the molecular structure and the absorption spectra of foam material,respectively.The porous structure of PPy/PVA foams and their photoelectric conversion behaviors were studied.The dimension of the pores is bigger than 100μm in diameter.Compared with the smooth film,the V_（oc） and I_（sc） of the foam film enhanced by 1.58-fold and 5.59-fold,respectively.

Damage Detection of Composite Material Intelligent Structure with a New Photoelectric System

A kind of photoelectric system that is suitable to measuring and to testing the damage of the composite material intelligent structure was presented. It can measure the degree of damage of the composite intelligent structure and it also can tell us the damage position in the structure. This system consists of two parts ： software and hardware. Experiments of the damage detection and the analysis of the composite material structure with the photoelectric system were performed, and a series of damage detection experiments was conducted. The results prove that the performance of the system is well and the effects of the measure and test are evident. Through all the experiments, the damage detection technology and test system are approved to be real-time, effective and reliable in the damage detection of the composite intelligent structure.

Photoelectric detection technology of laser seeker signals

The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals.

Performance of a plastic scintillation fiber dosimeter based on different photoelectric devices

The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal.Its features directly determine the overall performance of the dosimeter.For a plastic scintillation fiber dosimeter(PSFD)with a current readout mode,systematic studies of the stability and light-dose response were performed for the photomultiplier tube(PMT),silicon photomultiplier(SiPM),avalanche photodiode(APD),and photodiode(PD).The temperature stability,long-term stability,repeatability,signal-to-noise ratio(SNR),and current dose response of the PSFD with the abovementioned photoelectric devices were studied using a pulsed LED light source and the Small Animal Radiation Therapy platform.An exponential relationship between the dark/ne current and temperature was obtained for all the devices.I is shown that the APD is the most sensitive device to temperature,with a current dependence on temperature reaching 6.5%C^(-1)at room temperature,whereas for the other devices this dependence is always<0:6%C^(-1).In terms of long-term stability,the net current of PD can change by up to 4%when working continuously for 8 h and 2%when working intermittently for 32 h,whereas for the other devices,the changes are all<1%.For the dose response,the PMT and SiPM exhibit excellent linear responses and SNRs within the range of 0.1-60 Gy/min For the PSFD with a current readout mode,the performance of the PMT and SiPM is concluded to be better than that of the other devices in the study.In particular,the SiPM,which has a compact size,low bias voltage,and antimagnetic interference,has great advantages for further applications.

Experimental Investigation of Solar Panel Cooling by a Novel Micro Heat Pipe Array

A novel micro heat pipe array was used in solar panel cooling. Both of air-cooling and water-cooling conditions under nature convection condition were investigated in this paper. Compared with the ordinary solar panel, the maximum difference of the photoelectric conversion efficiency is 2.6%, the temperature reduces maximally by 4.7℃, the output power increases maximally by 8.4% for the solar panel with heat pipe using air-cooling, when the daily radiation value is 26.3 MJ. Compared with the solar panel with heat pipe using air-cooling, the maximum difference of the photoelectric conversion efficiency is 3%, the temperature reduces maximally by 8℃, the output power increases maximally by 13.9% for the solar panel with heat pipe using water-cooling, when the daily radiation value is 21.9 MJ.

Two‑Dimensional Platinum Diselenide:Synthesis,Emerging Applications,and Future Challenges

In recent years,emerging two-dimensional(2D)platinum diselenide(PtSe2)has quickly attracted the attention of the research community due to its novel physical and chemical properties.For the past few years,increasing research achievements on 2D PtSe2 have been reported toward the fundamental science and various potential applications of PtSe2.In this review,the properties and structure characteristics of 2D PtSe2 are discussed at first.Then,the recent advances in synthesis of PtSe2 as well as their applications are reviewed.At last,potential perspectives in exploring the application of 2D PtSe2 are reviewed.