最新刊期
卷 40 ， 期 3 ， 2019
- 摘要：Substrate temperature has very important influences on the performance of Cu2ZnSnSe4 (CZTSe) thin film solar cells. In this paper, CZTSe absorbers and solar cells prepared by co-evaporation process at different substrate temperatures are investigated. XRD results show additional reflections of SnSex of films deposited at substrate temperature(380℃). SEM measurements reveal that the quality of crystallization of CZTSe films improves with increasing substrate temperatures; meanwhile the open circuit voltage increases due to decreased grain-boundary recombination. However, J-V tests show that the efficiency of CZTSe solar cells fabricated at 460℃ is lower. The reason might be that CZTSe film growth starts with the formation of ZnSe at higher substrate temperature (460℃). And the ZnSe could form a barrier at the back contact which could reduce the short circuit current and fill factor. The best solar cell with an efficiency of 3.12% is obtained at medium substrate temperature of 420℃(active area 0.34 cm2).关键词：solar cells;CZTSe;co-evaporation;temperature170|98|0更新时间：2020-08-12
- 摘要：Ferroelectric materials have been very active in recent years as the infrared devices of photosensitive films. Their good piezoelectricity, ferroelectric, pyroelectric, photoelectric and nonlinear optical properties, and the integration of semiconductor technology, have a broad application prospect in the field of microelectronics and optoelectronic technology. The experiment combined the ferroelectric material lead zirconate titanate as the photosensitive layer and the GaN base high electron mobility transistor (HEMT). The photosensitive gate GaN based HEMT device was successfully prepared and detected under the light wavelength of 365 nm. After a large number of experimental tests, the light illumination of the device was found in this band. The saturation current reaches 28 mA, and the saturation current is increased by 12 mA compared with that without illumination. In addition, by reasonably changing the size of the device structure, including the gate length and the gate leakage distance, it is found that the saturation output current decreases in turn with the increase of the gate length, while the effect of the gap between the gate leakage distance on the threshold voltage and the saturation current is not significant. It can be seen that changing the device structure parameters can improve the performance of the device and the detection efficiency.关键词：high electron mobility transistor;photo gate;device structure;photovoltaic effect176|505|1更新时间：2020-08-12
- 摘要：Polystyrene(PS) spheres were used as a template, and the metal-assisted etching and wet chemical etching techniques were applied to prepare large-area Si corona-pillar arrays, silver nanoparticles were then grown in-situ to obtain silver-covered Si corona-pillar array(Ag/Si CPA) substrate. The experimental results show that the prepared substrate has excellent surface enhanced Raman scattering(SERS) characteristics, and its electromagnetic enhancement factor is up to 1.81×106. Meanwhile, the rhodamine molecule(R6G)-labeled DNA hairpin probe was immobilized on the surface of Ag/Si CPA substrate, and SERS signal detection was performed for getting the corresponding dose-response curve after complementary hybridization with various concentration of microRNA-106a. The results demonstrate that the detection of miRNA-106a, based on the SERS characteristic of Ag/Si CPA substrate, exhibits the advantages of specificity and high sensitivity with the limit of detection of 0.917 fmol·L-1 in the detection range of 1 fmol·L-1-100 pmol·L-1. In addition, compared with the real-time fluorescence quantitative polynucleotide chain reaction(RT-qPCR) method, not only the detection results are consistent, but the detection method based on SERS spectroscopy has a higher sensitivity.关键词：surface-enhanced Raman scattering;si pillar array;hairpin probe;tumor marker;miRNA158|214|2更新时间：2020-08-12
- 摘要：Radioluminescence isotope batteries have been extensively studied for their small size and long lifetime. The research work on isotope batteries is mainly aimed at improving the output performance. In this study, all-inorganic perovskite quantum dots were selected as fluorescent materials to match different photovoltaic devices with their tunable emission spectra. The maximum output power of the isotope battery is significantly increased after the spectral regulation, and can be increased by 2.51-3.97 times. At the same time, the application value and reference significance of spectral regulation in nuclear detection and nuclear medicine imaging are discussed.关键词：all-inorganic perovskite quantum dots;radioluminescence isotope battery;spectral regulation149|339|1更新时间：2020-08-12
- 摘要：In modern agricultural production, Light emitting diode(LED) is often used as a plant lighting source to supplement the agricultural crops. In order to improve the uniformity of the light source of LED plant lighting array, a new design method based on improved particle swarm optimization(PSO) of LED plant illuminated array light source is proposed in this paper. The mathematical modeling of the red and blue light LED plant light source array is carried out by MATLAB, and the red and blue light LED coordinates are found under the condition of high uniformity using the particle swarm optimization algorithm, and the red and blue light LED arrangement array in the two-dimensional case is designed. The stochastic inertia weight particle swarm optimization(random inertia particle swarm optimization) algorithm is used to design the three-dimensional scheme, and the two design schemes are verified with Tracepro and compared with the traditional red and blue light LED. The results show that, compared with the uniformity of the optical quantum flux density(Photosynthetic photon flux density,PPFD) designed by the common line by line array LED array, the uniformity of the two-dimensional design scheme is 88.7% by PSO optimization method, and the design is improved by 9.1% compared with the line by line arrangement. The PPFD uniformity of the 3D design is 92.6%, which is 3.9% higher than that of the two-dimensional design, and 13% higher than that of the equal spacing row by row arrangement. This experiment proves the feasibility of using PSO to design the light source of LED plant lighting array in two-dimensional and three-dimensional space, and improves the work efficiency at the same time in the simple design process.关键词：particle swarm optimization;light emitting diode;optical design;uniformity;plant factory184|153|2更新时间：2020-08-12
- 摘要：In order to investigate the influence of different luminous half angles on the radiation characteristics of circular LED array, the formula of illuminance, radius of spot and divergence angle of circular array are derived by using the illuminance formula of single LED chip. The Tracepro software is used to simulate the circular LED arrays with different luminous half angles, and MATLAB is used to fit the function values. The results show that, under the effective light spot area, with the increase of the single LED luminescence half angle, the central illuminance value of the circular array decreases gradually. The rate of the decrease is approximately linear, the radius of the spot and the divergence angle increase gradually, and the change first increases and then decreases. The radiation uniformity increases with the increase of the single LED luminescence half angle, and then keeps stable. The radiation uniformity of the circular array is the best when the single LED luminescent half angle is 60°, and the smaller the area of the receiving surface is, the higher the uniformity is. These conclusions provide a quantitative reference and theoretical basis for realizing the circular LED array lighting design.关键词：luminous half angle;circular array;effective spot radius;divergence angle;irradiation uniformity149|261|1更新时间：2020-08-12
- 摘要：A tunable single-dual wavelength erbium-doped fiber laser is proposed and demonstrated. The finer filtering is generated by compound filtering effect which is produced by cascaded fiber Bragg gratings(Cascaded FBGs) combined with Sagnac loop, the birefringence effect is introduced by adjusting polarization controller(PC) in Sagnac loop, and then the tunable fiber laser is obtained. Based on the coupled mode theory and transmission matrix, the characteristics of the structure are analyzed, experimental system is established, and the correctness of theoretical analysis is verified. The experimental results show that, by adjusting PC, the adjustable laser range is about 1 555.644~1 556.112 nm, the wavelength spacing of dual-wavelength is about 0.108~0.452 nm, the side mode suppression ratio (SMSR) of single-and dual-wavelength is more than 40 dB. In the stability test, the maximum wavelength drift of single-and dual-wavelength fiber laser is less than 0.008 nm. The proposed method has the advantages of simple structure, convenient tuning, easy implementation and high fineness, which can be applied in fields such as dense wavelength division multiplexing(DWDM) and all-optical communication systems.关键词：cascaded FBGs;Sagnac loop;birefringence effect;tunable wavelength;erbium-doped fiber laser202|268|5更新时间：2020-08-12
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Extraordinary Optical Transmission Coupled to A Gain Medium Based on The Subwavelength Nanostructure
摘要：As a focus on the study of metamaterials, the gain medium attracts a wide range of attention due to its excellent amplification characteristics. However, high external energy is needed to excite the gain material to compensate loss or create laser, which greatly limits the practical application of the gain materials. We investigate a computational scheme allowing for a self-consistent treatment of periodic arrays of subwavelength apertures coupled to a gain material incorporated into the nanostructure. Taking advantage of the amplification of extraordinary optical transmission(EOT) phenomena, the resonant electric-field intensity is enhanced associated with the effect of surface plasmon polariton(SPP). We present a simulation framework allowing for EOT coupled to gain media, which enables complete Ohmic loss compensation by using a moderate pump intensity level. The active gain media is represented with four-level atomic system by solving the semiclassical electronic rate equations. Finite-difference time-domain (FDTD) method incorporated with auxiliary differential equation is used to simulate electromagnetic field. Our results can be used as instruction for the realistic experiments, and provide a deep insight into the interaction between nanostructure and gain materials.关键词：gain material;finite-difference time-domain(FDTD) method;extraordinary optical transmission155|135|0更新时间：2020-08-12
Device Fabrication and Physics
- 摘要：A novel imidazole derivative L with electron-donating ability was designed and synthesized via the reactions of Debus-Radziszewski, Suzuki-Miyaura and Knoevenagel and characterized by FT-IR, 1H NMR. The photophysical properties in different polar solvents and density functional theory calculation results demonstrated that L exhibited typical intramolecular charge transfer(ICT) effect. The UV-Vis spectra and fluorescence spectra showed that L exhibited aggregation-caused quenching(ACQ) properties. The test results show that L can achieve the detection for PA(picric acid) in THF/H2O solution, and the limit of detection for PA is 3.7×10-6 mol/L.关键词：imidazole derivative;fluorescence chemosensor;picric acid (PA);solvatochromism effect120|203|0更新时间：2020-08-12
- 摘要：In this study, carbon dots(CDs) were synthesized by hydrothermal method using chitosan(CTs) as carbon source. The influences of hydrothermal temperature, hydrothermal time and chitosan mass fraction on the fluorescence intensity of carbon dots were investigated. The optical properties, chemical structure, crystal structure, and morphology of CDs were characterized by using ultraviolet spectrophotometer(UV-vis), fluorescence spectrophotometer, atomic force microscope(AFM), Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS) and X-ray diffractometer(XRD). The results showed that the quantum yield of CDs was 32.86% at a hydrothermal temperature of 200℃, a hydrothermal time of 9 h and a chitosan mass fraction of 2%. The carbon dots show a spherical shape with a main size of 3 to 10 nm. When the carbon dots excited at a wavelength of 335 nm, the emission peak is located at 410 nm and presents blue light. The selective analysis of metal ions shows that the fluorescence quenching effect of Fe3+ on the CDs is the most significant, indicating that the carbon dots have good sensitivity and high selectivity for Fe3+. The fluorescence quenching efficiency exhibits a linear response when Fe3+ concentration in the range of 0~100 μmol/L, which makes it possible to use the carbon dots as a fluorescent probe for the detection and characterization of Fe3+.关键词：carbon dots;chitosan;fluorescence probe;hydrothermal method;Fe3+298|466|3更新时间：2020-08-12
- 摘要：The theoretical analysis and numerical calculations of C@H2O composite particle's light scattering characteristics were carried out by using Mie scattering theory. The distribution of scattering intensity and polarization with scattering angle under different parameters were both presented. The relationship between optical section and particle's radius was also given. The results showed that the forward scattering intensity was more greatly influenced by each parameters than that by the back-scattering. The larger wavelength is, the weaker the intensity is. The forward scattering increases with the C core radius and water film thickness while the back-scattering is substantially retained. As for the polarization, linear polarized light appears at various angles, the larger incident wavelength is, the bigger carbon nucleus radius is, the thicker water film thickness is, the more polarization peaks. The scattering cross section and extinction cross section posses a peak value when carbon nucleus radius is approximately 0.1 μm.关键词：optical transmission;Mie scattering theory;C@H2O composite particle;scattering characteristics126|63|0更新时间：2020-08-12
- 摘要：The interaction of Mn doped ZnS quantum dots with malachite green and its metabolites residues leucomalachite green were studied. Firstly, chitosan coated ZnS:Mn quantum dots were prepared and characterized. Then, the interactions of the quantum dots to malachite green and leucomalachite green were investigated by ultraviolet-visible and fluorescence spectra. It was found that the quantum dots have a photocatalytic degradation effect on malachite green. After illumination for 60 min, the removal efficiency of malachite green with initial concentration of 20 mg·L-1 by 200 mg·L-1 quantum dots reached nearly 82%. The process kinetics can be successfully fitted to the first order kinetics of Langmuir-Hinshelwood model. The fluorescence intensity of leucomalachite green was quenched by the quantum dots. The dominating quenching mechanism belongs to dynamic quenching. Hydrogen bonding and van der Waals force play major role; binding processes are spontaneous. The results show that the quantum dots are promising candidates for applications in photocatalytic degradation of malachite green and non-toxic detecting leucomalachite green.关键词：quantum dots;malachite green;leucomalachite green;interaction146|137|2更新时间：2020-08-12
Synthesis and Properties of Materials
- 摘要：In order to study the evolutionary characteristics of thermal radiation generated by hypervelocity impacting on 2A12 aluminum plate, the measuring system was set up for characteristic measurement of thermal radiation caused by hypervelocity impacting. The methods of experimental measurement and theoretical calculation were adopted to obtain evolutionary processes of flash radiant intensity, flash radiant temperature, spectral radiant energy, radiant source area and luminous efficiency at close impact velocities(about 3 km/s) and different incident angles(the angle between the incident trajectory and the plate). The results indicate that flash radiant intensity, flash radiant temperature and spectral radiant energy all show the evolutionary characteristics of slow fading after rising sharply to the peak value, and decrease with the increase of incident angle. While the radiant source area continues to rise after the flash radiant temperature reaching the peak, the luminous efficiency increases with the decrease of incident angle, and it is in the order of 10-5 in this paper.关键词：hyperelocity impact;flash radiant intensity;flash radiant temperature;spectral radiant energy;luminous efficiency119|219|2更新时间：2020-08-12
- 摘要：The method and theory of extracting the sample optical constants with terahertz time domain system(THz-TDS) based on Fresnel formulas were demonstrated, the effect on the uncertainty of THz-TDS due to the thickness error was analyzed, and the uncertainty model was established. The measurement experiment of THz-TDS was designed, the refractive index of silicon wafer in terahertz band was extracted and the effect of error on extracting refractive index of sample was computed. Experimental results indicate that the measurement deviation increases with the thickness error increasing. For thicker samples, it has less effect on the measurement result carried by the same thickness error. The deviation of the refractive index measured by the system under 1 μm thickness error is 0.001 2 when the thickness of the sample is 994 μm, which is close to the simulation value of the model. Experimental results verify the availability of thickness error uncertainty model in measurement process, show the influence of thickness error on the measurement result, and have certain guiding significance on measure process and result analysis.关键词：terahertz time domain system(THz-TDS);optical constants;thickness error;uncertainty;monocrystalline silicon128|460|0更新时间：2020-08-12
- 摘要：Soluble solid content(SSC) is one of the important reference attributes for judging the internal quality of apples. The hyperspectral technique was used to obtain the reflectance spectrum of the region of interest of the apple, and using the Savitzky-Golay smoothing and direct orthogonal signal correction algorithms(DOSC) to perform gradient preprocessing on the spectral data.Backward interval partial least squares method(Bipls) prefers selecting 16 sub-intervals of 3, 5, 6, 7, 8, 9, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23 for a total of 177 wavelengths. Combined with the competitive adaptive reweighted sampling algorithm(CARS) for further screening, 7 characteristic wavelengths such as 449.6, 512.9, 544.8, 547.2, 594.3, 596.8, 928.2 nm were extracted. Partial least squares algorithm was used to develop SSC determination model based on characteristic wavelengths. The model was evaluated as Rc=0.906 2, RMSEC of 0.482 2, Rp=0.871 6 and RMSEP of 0.614 0. The performance of the model with Bipls and Bipls-SPA is more excellent, the effectiveness of Bipls combined with CARS algorithm in improving the detection accuracy of apple soluble solids content was proved.关键词：soluble solid content;backward interval partial least squares(Bipls);competitive adaptive reweighted sampling(CARS);partial least squares(PLS)153|128|8更新时间：2020-08-12
- 摘要：In order to compare the change of the pH value of mutton at 4℃ and 15℃ storage temperature, the optimal model of mutton during the storage period was optimized. The pH values of the samples were measured by pH acidity meter, the zero-order and first-order models of the traditional kinetics were established under two storage temperatures. The spectral data of mutton at two storage temperatures were acquired by near-infrared hyperspectral imaging(900-1 700 nm), and the spectral pretreatment was carried out after removing outlier. The feature wavelength is extracted by successive projection algorithm(SPA), and the partial least squares(PLSR) prediction model of full wavelength and feature wavelength is established. The optimal spectral model was combined with the kinetic model, and the spectral kinetic model of mutton was determined. The results show that the correlation coefficients of the conventional kinetic models at 4℃ and 15℃ were 0.502 and 0.912, respectively. The original spectrum was the best after modeling by PLSR at 4℃, and the correlation coefficient Rc was 0.821, Rp was 0.863. After the SG-S(3,7)+De-trending(4) pretreatment, the model was optimized by PLSR at 15℃. The correlation coefficient Rc was 0.876 and Rp was 0.819. It is feasible to detect the pH value of mutton by hyperspectral and traditional kinetic model, and the model can predict the storage period of mutton at 15℃.关键词：near-infrared hyperspectra;pH;kinetic model;storage temperature;PLSR146|184|5更新时间：2020-08-12
- 摘要：In order to detect the concentration accurately, Savitzky-Golay polynomial smoothing method is proposed to remove the redundant information of the three-dimensional fluorescence spectral data. The parallel factor analysis(PARAFAC) and alternating penalty trilinear decomposition(APTLD) are respectively adopted to decompose the spectrum data. The detection experiment of polycyclic aromatic hydrocarbons is designed in this paper. Fluorescence spectrum properties of ANA, NAP and their mixture are analyzed. We found that the main characteristic florescence peak of FLU exists in λex/λem=302/322 nm, and there is a continuous side peaks. The two characteristic florescence peaks which exist in ANA are λex/λem=290/322 nm and λex/λem=290/336 nm. When the excitation wavelength is 200~370 nm and the emission wavelength is 240~390 nm, the fluorescence spectra of FLU and ANA overlap seriously.The experimental results show that both algorithms can all distinguish FLU and ANA, both of them have a high average recovery rate. However, the APTLD algorithm has a better detection result.关键词：polycyclic aromatic hydrocarbons;fluorescence spectra;concentration detection;Savitzky-Golay;APTLD algorithm167|128|2更新时间：2020-08-12
- 摘要：In order to detect the rot disease of postharvest blueberries quickly, effectively and accurately, the rot disease of postharvest blueberries was detected by hyperspectral imaging technology with different detection models. According to analyse the difference of the spectral relative reflectance between the normal blueberries and the disease blueberries, the spectral Information segmentation(SIS) was proposed to segment the disease regions of blueberries to solve the problem that the conventional threshold segmentation method is difficult to accurately segment blueberry disease regions due to the indistinct color characteristics of the normal blueberries regions and the disease blueberries regions. According to the difference of spectrum in 450 nm to 1 000 nm, the regional feature selection(RFS) was put forward that divided the spectral relative reflectance(450-1 000 nm) into the two regions. The first region was in visible spectrum ranges 450-780 nm and the second region in near infrared ranges 780-1 000 nm.Then CARS and SPA were used to extract the characteristic wavelengths from spectral data in two regions. Finally, relevance vector machines(RVM) model and radial basis function(RBF) model were used to detect the rot disease of blueberries. By comparing the detection effects of different models, the CARS-RBF model in the combined regions of first region and second region had best detection effect and the characteristic wavelengths were 655.8, 710.9, 752.2, 759.9, 761.2, 866.5, 969.7 nm. The detection accuracy of the normal blueberries and the disease blueberries in the training sets and the testing sets were 98.3%, 98.6% and 97.5%, 98.75%, respectively. According to the result of the detection,we can draw a conclusion that the spectral information segmentation(SIS) and regional feature selection(RFS) were used to detect blueberry diseases effectively, which provide a new reference method for on-line detection and sorting of blueberries.关键词：hyperspectral imaging;rot disease of postharvest blueberries;spectral information segmentation;regional feature selection;nondestructive detection143|241|3更新时间：2020-08-12
Luminescence Applications and Interdisciplinary Fields
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