Calculated and Experimental Research of Sheet Resistances of Laser-Doped Silicon Solar Cells

The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15 Ω/. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.

Photoluminescence spectroscopy of sputtering Er-doped silicon-rich silicon nitride films

Er-doped silicon-rich silicon nitride （SRN） films were deposited on silicon substrate by an RF magnetron reaction sputtering system. After high temperature annealing, the films show intense photoluminescence in both the visible and infrared regions. Besides broad-band luminescence centered at 780 nm which originates from silicon nanocrystals, resolved peaks due to transitions from all high energy levels up to 2H11/2 to the ground state of Er^3＋ are observed. Raman spectra and HRTEM measurements have been performed to investigate the structure of thefilms, and possible excitation processes are discussed.

Photoluminescence Properties of Er-doped SiC Thin Film

Hydrogenated amorphous silicon carbide （a-SixC1-x：H） films were grown on Si substrate by plasma-enhanced chemical vapor deposition. Fixed flow rate of H2 and different flow ratio of SiHJCH4 were used. Er-doped a-SixC1-x ： H （a-SixC1-x-H ：Er） films were prepared by implanting Er into the a- Si,C1-x-H host materials followed by annealing at different temperatures. The structure properties of the films were characterized by X-ray photoelectron spectroscopy （XPS）, Raman spectra. infrared absorption Photoluminescence spectra （IR） and （PL） intensities depending on flow rates and annealing temperatures were studied. High annealing temperature is not favorable for PL because of C-surface segregation. It is shown that thermal quenching of this material is small by comparing the PL intensities of a-SixC1-x-H： Er at room temperature and low temperature.

Precise determination of characteristic laser frequencies by an Er-doped fiber optical frequency comb

Femtosecond optical frequency combs correlate the microwave and optical frequencies accurately and coherently.Therefore,any optical frequency in visible to near-infrared region can be directly traced to a microwave frequency.As a result,the length unit“meter”is directly related to the time unit“second”.This paper validates the capability of the national wavelength standards based on a home-made Er-doped fiber femtosecond optical frequency comb to measure the laser frequencies ranging from visible to near-infrared region.Optical frequency conversion in the femtosecond optical frequency comb is achieved by combining spectral broadening in a highly nonlinear fiber with a single-point frequencydoubling scheme.The signal-to-noise ratio of the beat notes between the femtosecond optical frequency comb and the lasers at 633,698,729,780,1064,and 1542 nm is better than 30 d B.The frequency instability of the above lasers is evaluated by using a hydrogen clock signal with a instability of better than 1×10^(-13)at 1-s averaging time.The measurement is further validated by measuring the absolute optical frequency of an iodine-stabilized 532-nm laser and an acetylenestabilized 1542-nm laser.The results are within the uncertainty range of the international recommended values.Our results demonstrate the accurate optical frequency measurement of lasers at different frequencies using the femtosecond optical frequency comb,which is not only important for the precise and accurate traceability and calibration of the laser frequencies,but also provides technical support for establishing the national wavelength standards based on the femtosecond optical frequency comb.

A Temperature-Insensitive Amplified Spontaneous Emission Broadband Source Based on Er-Doped Fiber

To obtain a stable amplified spontaneous emission（ASE） source for complex environment applications, we design an ASE source and study the output power and spectral characteristics under different ambient temperatures.We optimize the structure of the ASE source to flatten the ASE spectrum, and study the output characteristics in terms of output power and optical spectrum under different pump powers. Then the performance of the ASE source is investigated in the temperature range from-18.9°C to 50°C. A stable-power and flat-spectrum ASE source can be obtained by structural optimization and pump control.

Dispersive Nonlinearity in Er-Doped Optical Fiber

Optical dispersive nonlinearities in Er-doped optical fiber are discussed and measured at the third window wavelength 1.55 μm for optical communications firstly. The experimental method, which is developed by us, is based on dynamic scanning for fixed-point-interference (DSFPI) of two fiber beams. The real part and complex value of the third-order susceptibility at the wavelength are also obtained from the measured Kerr coefficient and nonlinear-absorption coefficient reported elsewhere.

Theoretical modelling of the effect of photon lifetime on the output dynamics of Er-doped distributed feedback fibre lasers

By employing a simple model of describing three-level lasers, we have theoretically investigated the effect of photon lifetime on the output dynamics of Er-doped distributed feedback fibre lasers. And based on the theoretical analysis we have proposed a promising method to suppress self-pulsing behaviour in the fibre lasers.

基于In Silicon模拟消化的北极虾DPP-Ⅳ抑制肽活性分析

北极虾具有很高的营养价值,在食品领域已引起越来越多的关注。对北极虾蛋白进行In Silicon模拟消化获得寡肽,通过PeptideRanker活性评分及理化性质分析,从中筛选出具有潜在生物活性的寡肽。使用ToxinPred分析和BIOPEP-UWM生物活性预测,发现部分寡肽具有二肽基肽酶-Ⅳ(dipeptidyl peptidase-Ⅳ,DPP-Ⅳ)抑制活性,最终确定WFP(一种三肽,Trp-Phe-Pro)具有最优的DPP-Ⅳ抑制活性肽。分子对接表明,WFP和DPP-Ⅳ能够形成稳定的复合物,其结合能为-6.93 kcal/mol,进一步研究表明,WFP通过与DPP-Ⅳ S1、S2、S3三个活性口袋中的9个氨基酸残基发生相互作用而抑制其活性。本研究为阐释北极虾营养价值及生物活性肽的开发提供了理论依据。

Innovative Solutions for High-Performance Silicon Anodes in Lithium-Ion Batteries:Overcoming Challenges and Real-World Applications

Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity degradation.Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle resistance.This review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous coatings.Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency.We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss.Our review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical discussions.It offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial feasibility.In conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.

Observation of 550 MHz passively harmonic mode-locked pulses at L-band in an Er-doped fiber laser using carbon nanotubes film

We demonstrate a passively harmonic mode-locked（PHML） fiber laser operating at the L-band using carbon nanotubes polyvinyl alcohol（CNTs-PVA） film. Under suitable pump power and an appropriate setting of the polarization controller（PC）, the 54^（th） harmonic pulses at the L-band are generated with the side mode suppression ratio（SMSR） better than 44 dB and a repetition frequency of 503.37 MHz. Further increasing the pump power leads to a higher frequency of 550 MHz with compromised stability of 38.5 dB SMSR. To the best of our knowledge, this is the first demonstration on the generation of L-band PHML pulses from an Er-doped fiber laser based on CNTs.

Chirp Extraction of Self-Similar Pulses in a Passively Mode-Locked Er-doped Fiber Laser

In this paper, we adopt cloud computing in a specific scientific computing field for its virtualization, distribution and dynamic extendibility as follows: We obtain high-energy parabolic self-similar pulses by numerical simulation using our non-distributed passively mode-locked Er-doped fiber laser model. For researching characteristics of these wave-breaking-free self-similar pulses, chirp of them must be extracted. We propose several time-frequency analysis methods adopted in chirp extraction of ultra-short optical pulses for the first time and discuss the advantages and disadvantages of them in this particular application.

Using Reduced Graphene Oxide to Generate Q-Switched Pulses in Er-Doped Fiber Laser

Using the reduced graphene oxide（rGO） as a saturable absorber（SA） in an Er-doped fiber（EDF） laser cavity,we obtain the Q-switching operation. The rGO SA is prepared by depositing the GO on fluorine mica（FM） using the thermal reduction method. The modulation depth of rGO/FM is measured to be 3.2%. By incorporating the rGO/FM film into the EDF laser cavity, we obtain stable Q-switched pulses. The shortest pulse duration is3.53 μs, and the maximum single pulse energy is 48.19 nJ. The long-term stability of working is well exhibited.The experimental results show that the rGO possesses potential photonics applications.

Silicone oil as a corneal lubricant to reduce corneal edema and improve visualization during

AIM:To evaluate the efficacy and safety of silicone oil(SO)as a corneal lubricant to improve visualization during vitrectomy.METHODS:Patients who underwent vitreoretinal surgery were divided into two groups.Group 1 was operated on with initial SO(Oxane 5700)as a corneal lubricant.Group 2 was operated on with initial lactated ringer’s solution(LRS)and then replaced with SO as required.Fundus clarity was scored during the surgery.Fluorescein staining was performed to determine the damage to corneal epithelium.RESULTS:Totally 114 eyes of 114 patients were included.Single SO use maintained a clear cornea and provided excellent visualization of surgical image.In group 1,the fundus clarity was grade 3 in 41/45 eyes and grade 2 in 4/45 eyes.In group 2,corneal edema frequently occurred after initial LRS use.The fundus clarity was grade 3 in 19/69 eyes,2 in 37/69 eyes and 1 in 13/69 eyes(P<0.05).SO was applied in 29 eyes of initial LRS use with subsequent corneal edema,which eliminated the corneal edema in 26 eyes.Corneal fluorescein staining score in group 1 was 0 in 28 eyes,1 in 11 eyes and 2 in 6 eyes,and 40,20 and 9,respectively,in group 2(all P>0.05).CONCLUSION:The use of SO as a corneal lubricant is effective and safe for preserving and improving corneal clarity and providing clear surgical field during vitrectomy.

Regulation of 2-acetyl-1-pyrroline and grain quality in early-season indica fragrant rice by nitrogen and silicon fertilization under different plantation methods

Fragrant rice has a high market value,and it is a popular rice type among consumers owing to its pleasant flavor.Plantation methods,nitrogen(N)fertilizers,and silicon(Si)fertilizers can affect the grain yield and fragrance of fragrant rice.However,the core commercial rice production attributes,namely the head rice yield(HRY)and 2-acetyl-1-pyrroline(2-AP)content of fragrant rice,under various nitrogen and silicon(N-Si)fertilization levels and different plantation methods remain unknown.The field experiment in this study was performed in the early seasons of 2018 and 2019 with two popular indica fragrant rice cultivars(Yuxiangyouzhan and Xiangyaxiangzhan).They were grown under six N-Si fertilization treatments(combinations of two levels of Si fertilizer,0 kg Si ha^(−1)(Si0)and 150 kg Si ha^(−1)(Si1),and three levels of N fertilizer,0 kg N ha^(−1)(N0),150 kg N ha^(−1)(N1),and 220 kg N ha^(−1)(N2))and three plantation methods(artificial transplanting(AT),mechanical transplanting(MT),and mechanical direct-seeding(MD)).The results showed that the N-Si fertilization treatments and all the plantation methods significantly affected the HRY and 2-AP content and related parameters of the two different fragrant rice cultivars.Compared with the Si0N0 treatment,the N-Si fertilization treatments resulted in higher HRY and 2-AP contents.The rates of brown rice,milled rice,head rice,and chalky rice of the fragrant rice also improved with the N-Si fertilization treatments.The N-Si fertilization treatments increased the activities of N metabolism enzymes and the accumulation of N and Si in various parts of the fragrant rice,and affected their antioxidant response parameters.The key parameters for the HRY and 2-AP content were assessed by redundancy analysis.Furthermore,the structural equation model revealed that the Si and N accumulation levels indirectly affected the HRY by affecting the N metabolism enzyme activity,N use efficiency,and grain quality of fragrant rice.Moreover,high N and Si accumulation directly promoted the 2-AP content or affected the antioxidant response parameters and indirectly regulated 2-AP synthesis.The interactions of the MT method with the N-Si fertilization treatments varied in the fragrant rice cultivars in terms of the HRY and 2-AP content,whereas the MD method was beneficial to the 2-AP content in both fragrant rice cultivars under the N-Si fertilization treatments.

Numerical Simulation on Broad-band Er-doped Superfluorescent Fiber Source Filter Using Long Period Chirped Fiber Grating

Given is an analysis of broad-band Er-doped superfluorescent fiber source(EDSFS)filter using long period chirped fiber grating by transmission matrix method.For our EDSFS attenuated amplitude demand and the flattened wavelength range demand,proposed are the key factors of designing such filters of high performances.The simulation result demonstrates that such type filters have an enough attenuation to flatten the dramatic increase in output amplified spontaneous emission(ASE)in the wavelength range of 1529nm^1535nm by choosing conformable fiber filter parameters such as chirped degree,original period,induced index change,length of the fiber filter,and then broad-band EDSFS could be achieved.

Double Clad Er-doped Fiber Amplifier

Presented is a theoretical study of double-clad Er-doped fiber power amplifier(EDFA). Two kinds of double clad fibers(DCF) with rectangular and "flower" inner clad shapes are studied, and these fibers have different coupling constants and propagation losses. We calculate the effective pump power absorption ratio along the fiber with different coupling constants from the first cladding to the doped core and with different propagation losses for the power in the inner cladding. Then the gains of the double clad Er-doped fiber amplifiers versus fiber lengths are calculated using the EDFA model based on propagation and rate equations of a homogeneous, two-level medium.

Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries

Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.

Ultrafast dynamics of femtosecond laser-induced high spatial frequency periodic structures on silicon surfaces

Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than the diffraction limit,making it a useful method for efficient nanomanufacturing.However,compared with the low-spatial-frequency LIPSS(LSFL),the structure size of the HSFL is smaller,and it is more easily submerged.Therefore,the formation mechanism of HSFL is complex and has always been a research hotspot in this field.In this study,regular LSFL with a period of 760 nm was fabricated in advance on a silicon surface with two-beam interference using an 800 nm,50 fs femtosecond laser.The ultrafast dynamics of HSFL formation on the silicon surface of prefabricated LSFL under single femtosecond laser pulse irradiation were observed and analyzed for the first time using collinear pump-probe imaging method.In general,the evolution of the surface structure undergoes five sequential stages:the LSFL begins to split,becomes uniform HSFL,degenerates into an irregular LSFL,undergoes secondary splitting into a weakly uniform HSFL,and evolves into an irregular LSFL or is submerged.The results indicate that the local enhancement of the submerged nanocavity,or the nanoplasma,in the prefabricated LSFL ridge led to the splitting of the LSFL,and the thermodynamic effect drove the homogenization of the splitting LSFL,which evolved into HSFL.

Effect of Silicon Amendment on Growth and Nitrogen Status of Common Landscaping Plants

Agriculture and natural vegetations in South Florida face with significant environmental threats such as heat and saltwater intrusion. This study aimed to investigate how silicon application could improve growth parameters and plant health of landscaping plants under extreme temperatures, influenced by global climate changes. Cocoplum (Chrysobalanus icaco), cabbage palm (Sabal palmetto), satinleaf (Chrysophyllum oliviforme), and wild coffee (Psychotria nervosa) plants received an initial slow-release fertilizer of 15 g/pot with an 8N-3P-9K composition. Silicon was applied as a 1% silicic acid solution, with concentrations ranging from 0 g/pot to 6 g/pot of 7.5 L. Evaluations were carried out every 30 days, continuing until 180 days after the treatment was completed. Phenotypic traits, including leaf count and plant height, were assessed alongside measurements from handheld optical non-destructive sensors. These measurements included the normalized difference vegetation index (NDVI), SPAD-502, and atLEAF chlorophyll meters. Application of 4 g/pot and 6 g/pot of silicon significantly improved NDVI values (0.78). Conversely, cocoplum plants exhibited greater plant height (79.6) at 0 g/pot silicon compared to other treatments. In wild coffee samplings, the control group showed the highest plant height and SPAD readings (93.49) compared to other treatments. Interestingly, the control treatment also demonstrated a superior atLEAF value as compared to other treatments, while the tallest samplings were observed with 6 g/pot of silicon (62.82) in cabbage palm plants. The findings indicate that silicon application positively influenced plant growth, particularly evident in cabbage palms. However, cocoplum and wild coffee exhibited a negative correlation between plant height and silicon concentrations.

‘Jelly to Joule’:Direct laser writing of sustainable jellyfish-based ‘graphenic silicon’ anodes for environmentally remediating high-performance lithium-ion batteries

The ramifications of global climate change and resource scarcities have made it imperative to re-examine the definition of sustainable energy-storage systems.It is crucial to recognize that not all renewable resources are inherently sustainable,and their full impact on the environment must be assessed.With the proliferation of invasive jellyfish species wreaking havoc on marine ecosystems and economies worldwide,utilizing overabundant jellyfish as a carbon source presents an opportunity to create energy-storage systems that are both financially beneficial and environmentally remediating.Accordingly,a comprehensive approach to sustainability also requires eco-friendly solutions throughout the entire lifecycle,from material sourcing to battery production,without compromising highperformance requirements.Currently,most electrode syntheses for lithium-ion batteries(LIBs) employed are energy-intensive,multiple-steps,complex,and additive-heavy.In response,this work pioneers the straightforward use of low-energy laser irradiation of a jellyfish biomass/silicon nanoparticle blend to encapsulate the silicon nanoparticles in-situ within the as-forming conductive carbonized matrix,creating sustainable and additive-free composite anodes.The self-standing anode is directly synthesized under ambient conditions and requires no post-processing.Here,a laser-synthesized conductive threedimensional porous carbon/silicon composite anode from raw jellyfish biomass for LIBs is presented,displaying outstanding cyclic stability(>1000 cycles),excellent capacity retention(>50% retention after1000 cycles),exceptional coulombic efficiency(>99%),superb reversible gravimetric capacity(>2000 mAh/g),and high rate performance capability(>1.6 A/g),paving a new path to future sustainable energy production.