通讯机构：
[Ma, HC ] W;Wuhan Univ, Sch Remote Sensing & Informat Engn, Wuhan 430079, Peoples R China.
关键词：
LiDAR;Boundary point extraction;Outline extraction;Dominant direction detection;Contextual topological optimization
摘要：
It is challenging to extract satisfactory building outlines from LiDAR data due to the unorganized point cloud and complex building shapes. To solve the issues, a method using adaptive tracing alpha shapes (ATAS) and contextual topological optimization is proposed. First, the ATAS method is used to extract sequential boundary points. After that, a method based on point cloud distribution analysis is developed to obtain building dominant directions and line segments of outlines. Finally, regularized outlines are obtained by adjusting all line segments simultaneously under the framework of global energy optimization that considers the geometric errors and contextual geometric relationships between adjacent line segments. Experimental results verify that the proposed ATAS method can efficiently extract sequential boundary points with a minimum 98.49% correctness. In addition, the extracted outlines are attractive and the minimum values of the RMSE, PoLiS, and RCC metrics of the extracted outlines are 0.48 m, 0.44 m, and 0.31 m, respectively, showing the effectiveness of the proposed method.
作者机构：
[Zhang, Deng-Wei] Luoyang Inst Sci & Technol, Dept Math & Phys, Luoyang 471023, Peoples R China.;[Zheng, Li-Li] Jianghan Univ, Key Lab Optoelect Chem Mat & Devices, Minist Educ, Wuhan 430074, Peoples R China.;[Wang, Mei] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430040, Peoples R China.;[Zhou, Yuan] Hubei Univ Automot Technol, Sch Elect & Informat Engn, Hubei Key Lab Energy Storage & Power Battery, Shiyan 442002, Peoples R China.;[Lu, Xin-You] Huazhong Univ Sci & Technol, Sch Phys, Wuhan 430074, Peoples R China.
通讯机构：
[Zheng, LL ] J;Jianghan Univ, Key Lab Optoelect Chem Mat & Devices, Minist Educ, Wuhan 430074, Peoples R China.
摘要：
We investigate theoretically the chaotic dynamics in an optomechanical system composed of coupled optical resonators. We find that introducing additional loss through a nanotip can induce chaotic motion. The underlying reason for this unconventional phenomenon lies in steering the system parameters via an additional loss that can bring the system to the vicinity of a chaotic regime, which dynamically enhances the optomechanical nonlinearity and suppresses the negative influence of loss, giving rise to the emergence of chaotic motion. Our work may open a different avenue for designing and developing chaotic systems in optomechanics and provide theoretical guidance for chaotic secure communication.
摘要：
In the last few decades, nanoparticles have been a prominent topic in various fields, particularly in agriculture, due to their unique physicochemical properties. Herein, molybdenum copper lindgrenite Cu(3)(MoO(4))(2)(OH)(2) (CM) nanoflakes (NFs) are synthesized by a one-step reaction involving α-MoO(3) and CuCO(3)⋅Cu(OH)(2)⋅xH(2)O solution at low temperature for large scale industrial production and developed as an effective antifungal agent for the oilseed rape. This synthetic method demonstrates great potential for industrial applications. Infrared spectroscopy and X-ray diffraction (XRD) results reveal that CM samples exhibit a pure monoclinic structure. TG and DSC results show the thermal stable properties. It can undergo a phase transition form copper molybdate (Cu(3)Mo(2)O(9)) at about 300°C. Then Cu(3)Mo(2)O(9) nanoparticlesdecompose into at CuO and MoO(3) at 791°C. The morphology of CM powder is mainly composed of uniformly distributed parallelogram-shaped nanoflakes with an average thickness of about 30nm. Moreover, the binding energy of CM NFs is measured to be 2.8eV. To assess the antifungal properties of these materials, both laboratory and outdoor experiments are conducted. In the pour plate test, the minimum inhibitory concentration (MIC) of CM NFs against Sclerotinia sclerotiorum (S. sclerotiorum) is determined to be 100ppm, and the zone of inhibiting S. sclerotiorum is 14mm. When the concentration is above 100nm, the change rate of the hyphae circle slows down a little and begins to decrease until to 200ppm. According to the aforementioned findings, the antifungal effects of a nano CM NFs solution are assessed at different concentrations (0ppm (clear water), 40ppm, and 80ppm) on the growth of oilseed rape in an outdoor setting. The results indicate that the application of CM NFs led to significant inhibition of S. sclerotiorum. Specifically, when the nano CM solution was sprayed once at the initial flowering stage at a concentration of 80ppm, S. sclerotiorum growth was inhibited by approximately 34%. Similarly, when the solution was sprayed once at the initial flowering stage and once at the rape pod stage, using a concentration of 40ppm, a similar level of inhibition was achieved. These outcomes show that CM NFs possess the ability to bind with more metal ions due to their larger specific surface area. Additionally, their semiconductor physical properties enable the generation of reactive oxygen species (ROS). Therefore, CM NFs hold great potential for widespread application in antifungal products.
关键词：
air decomposition pollutants;MoS2;ZnO;TiO2;gas sensor;DFT
摘要：
When partial discharges occur in air-insulated equipment, the air decomposes to produce a variety of contamination products, resulting in a reduction in the insulation performance of the insulated equipment. By monitoring the concentration of typical decomposition products (CO, NO, and NO(2)) within the insulated equipment, potential insulation faults can be diagnosed. MoS(2) has shown promising applications as a gas-sensitive semiconductor material, and doping metal oxides can improve the gas-sensitive properties of the material. Therefore, in this work, MoS(2) has been doped using the popular metal oxides (ZnO, TiO(2)) of the day, and its gas-sensitive properties to the typical decomposition products of air have been analyzed and compared using density functional theory (DFT) calculations. The stability of the doped system was investigated using molecular dynamics methods. The related adsorption mechanism was analyzed by adsorption configuration, energy band structure, density of states (DOS) analysis, total electron density (TED) analysis, and differential charge density (DCD) analysis. Finally, the practical application of related sensing performance is evaluated. The results show that the doping of metal oxide nanoparticles greatly improves the conductivity, gas sensitivity, and adsorption selectivity of MoS(2) monolayer to air decomposition products. The sensing response of ZnO-MoS(2) for CO at room temperature (25 °C) reaches 161.86 with a good recovery time (0.046 s). TiO(2)-MoS(2) sensing response to NO(2) reaches 3.5 × 10(6) at 25 °C with a good recovery time (0.108 s). This study theoretically solves the industrial challenge of recycling sensing materials and provides theoretical value for the application of resistive chemical sensors in air-insulated equipment.
摘要：
Two-dimensional transition metal disulfides (TMDs) heterojunction is a very promising non-precious metal catalyst that has been widely used as a catalyst for hydrogen evolution reactions. In this paper, the effects of different positions of Se vacancies on the electronic structure and hydrogen evolution reaction electrocatalyst of MoSe2/WSe2 heterojunction are investigated by first-principles calculations. After the introduction of vacancy, defect states appear between the conduction band bottom and the Fermi energy level of the heterojunction. This is more favorable for the electron transfer between H and the substrate. The results of the density of states calculations indicate that the defect states appear because the d orbitals of the transition metal atoms containing the Se vacancy layer hybridize with the p orbitals of the Se atoms. The differential charge density indicates that the Se vacancies promote the charge transfer of MoSe2/WSe2. In addition, calculations of the Gibbs free energy for the hydrogen evolution reaction of heterojunctions show that Se vacancies (especially the outer vacancies) enhance the electrocatalytic hydrogen precipitation performance of heterojunctions. The results provide a new way to regulate the hydrogen evolution properties of MoSe2/WSe2 heterojunctions.
通讯机构：
[Chen, RS ; Ren, XH ] W;Wuhan Univ Sci & Technol, Inst Adv Mat & Nanotechnol, Sch Chem & Chem Engn, State Key Lab Refractories & Met, Wuhan 430081, Peoples R China.;Wuhan Univ Sci & Technol, Minist Educ, State Key Lab Refractories & Met & Resources Utili, Key Lab Ferous Metalurgy, Wuhan 430081, Peoples R China.;Wuhan Univ Sci & Technol, Fac Mat, Hubei Prov Key Lab New Proc Ironmaking & Steel mak, Wuhan 430081, Peoples R China.
关键词：
CO2RR;Copper-based catalyst;Pyridine;Modification;Surface active sites
摘要：
Copper -based catalysts have been extensively investigated for electrocatalytic reduction of CO2 owing to their unique capabilities. To our notice, organic molecules can be employed as molecular modifiers to tailor the CO2 reduction selectivity of Cu -based catalysts. Herein, three kinds of molecular modifiers, pyridine, triethylamine, and potassium hydroxide have been utilized for fabricating Cu -based electrocatalysts. Experimental investigations reveal that pyridine as molecular modifiers have the ability to alter the surface active sites of the Cubased catalysts. The modification can facilitate the conversion of CO2 into HCOOH. Notably, the highest Faradaic efficiency achieved in our tests for HCOOH can reach to an impressive value of 80.2 %. Moreover, the catalyst maintains its structure and performance with high stability that exceeding 10 h at a current density of 30 mA cm -2 (-1.1 V vs. RHE). Based on structural characterization and theoretical calculations, we propose that the pyridine molecule can facilitate CO2 accumulation, and the pyridine modification of the CuO/Cu(OH)2 surface active site can reduce the reaction energy barrier for the electrocatalytic reduction of CO2 to HCOOH.
摘要：
While highly sensitive elastic strain sensors have been widely investigated, the time-dependent stress sensitivity of viscoelastic MWCNT/polyethylene nanocomposite stress sensors remains to be explored. In this paper, we develop an electromechanically coupled homogenization scheme to reveal the time-dependent stress sensing performances of viscoelastic MWCNT/polyethylene nanocomposite sensors. In the time-dependent context, the complex moduli and electrical conductivity are selected as the dual homogenization parameters. The time-dependent stress sensitivity is illustrated through the viscoelastic imperfect interface connection and stress-induced tunneling distance. The predicted stress sensing capacities of viscoelastic MWCNT/polyethylene nanocomposite stress sensors are shown to be consistent with the experiments under the constant stress loading. It reveals that the stress sensitivity factor increases with the loading time under constant stress. The optimal MWCNT aspect ratio for high sensing capacities exhibits an increasing trend regarding the MWCNT volume fraction. The uncovered sensing characteristics can provide microstructural design guidance in high-performance nanocomposite stress sensors.
关键词：
Air discharge pollutants;Single-walled CNT;Geometric structure;Gas adsorption;DFT
摘要：
Air is a good insulating medium under normal conditions. The insulation performance of many electrical equipment is closely related to air. The detection of air decomposition pollutants is considered to be one of the effective ways to diagnose the fault of air insulated power equipment. Based on the first-principles, the adsorption and sensing characteristics of Single-walled CNT modified by transition metal clusters (Crn) for air discharge pollutants (CO, NOx) were analyzed. Firstly, through the modeling and analysis of different doping sites, four most stable models of Crn doped SWCNT are obtained, and their resistance is briefly analyzed. On the basis of these four configurations, the most stable adsorption configurations were found. The corresponding adsorption energy, adsorption distance and transfer charge are obtained. Then, the differential charge density, frontier molecular orbitals, adsorption selectivity and desorption properties of each system were analyzed. The result is that Crn-SWCNT surface has a good adsorption capacity for pollutants. The theoretical recovery time is not ideal at room temperature. However, CO can be rapidly desorbed from the surface of Crn-SWCNT at extremely high temperatures. Interestingly, Crn-SWCNT can be used as solid adsorption materials for purifying CO, NOx. This work provides a new idea for clean air to treat air discharge pollutants.
通讯机构：
[Fang, C ] W;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.
关键词：
Flowering plants;Feature extraction;Image color analysis;Convolutional neural networks;Computational modeling;YOLO;Real-time systems;Image recognition;Agricultural products;Tomato flower fruit recognition;C3Faster;convolutional neural networks;lightweight
摘要：
In order to monitor the growth and development of tomatoes, and improve the efficiency of flower and fruit thinning and tomato picking, this paper constructs a tomato flower and fruit dataset and proposes a TF-YOLOv5s model for the detection of tomato flowers and fruits in natural environments. Based on the YOLOv5s model, a C3Faster module is introduced to reduce the number of parameters and calculations while maintaining detection accuracy. The regular convolution is replaced by depth-wise separable convolution (DWConv) to avoid parameter redundancy. To improve the convergence and accuracy of the model, this paper replaces Complete Intersection over Union (CIoU) loss with Efficient Intersection over Union (EIoU) loss. The Squeeze-and-Excitation (SE) module is added to improve the model’s sensitivity to the features of the tomato flowers and fruits. Compared with the baseline model, the number of parameters is reduced by 54.5%, the weight file is reduced by 52.8%, the Floating-point Operation Per second (FLOPs) is reduced by 48.7%. The detection accuracy of tomato flowers and fruits mAP@0.5 has improved by 1.4% and 1.2% respectively. TF-YOLOv5s is used to detect three types of targets: tomato flowers, red tomatoes, and green tomatoes, and mAP@0.5 of which can reach as high as 95.2%. Furthermore, the improved algorithm is deployed on two edge computing devices to verify its effectiveness. Experimental results show that the algorithm in this paper can achieve high detection with less computational resources. This algorithm has the potential value of application in practical tomato production.
摘要：
This paper presents a stepped electromagnetic bandgap(EBG) hosted on the T-shaped stepped stub with an inverted H-shaped slot etched on the ground to enhance bandwidth and improve isolation for a compact UWB-MIMO antenna developed from our previous design. The characteristic mode analysis is used to offer physical insight into the operation phenomena taking place in the evolution of antenna. The proposed antenna has a compact size of $27\times 22\times 0.8$ mm and realize bandwidth from 3.07 GHz to 11.1 GHz, keeping the isolation more than 20 dB. Key parameters evaluating the antenna performance like radiation pattern, gain, radiation efficiency above 75% and envelope correlation coefficient below 0.05 are investigated. The simulated and measured results agree well, testifying the proposed MIMO antenna is a suitable candidate for UWB applications.
关键词：
Cr2 dimer;g-CN;Gas adsorption;Gas-sensitive;Green gas
摘要：
Currently, CF3SO2F shows great potential as a green insulating gas to replace SF6 in the electrical industry to support the dual-carbon program. However, it has the potential to undergo partial discharges and thus decomposition under the operating voltage of the power grid, and the gas -sensitive detection technique is an effective method to diagnose this problem. In this work, the gas -sensitive properties of the Cr2@g-CN interface for each harmful gas molecule were investigated from a microscopic point of view, using the harmful gases (SO2, HF, SO2F2, CF4) that may be produced by CF3SO2F as the detection targets. Then, the performance of Cr2@g-CN interface as a gas sensor material in practical applications was predicted. The final results revealed that the Cr2@g-CN interface is most suitable as a potential gas -sensitive material for SO2 gas sensors. The exploration of humidity effects suggests that Cr2@g-CN remains a promising SO2 gas sensing material for practical applications in specific humidity environments. This work reveals the origin of the excellent properties of Cr2@g-CN as a gas sensor material and provides new ideas for the detection of CF3SO2F decomposition products.
期刊：
Digital Signal Processing,2024年144:104288 ISSN：1051-2004
通讯作者：
Ou, WH
作者机构：
[Xiong, Jiahao; Ou, Weihua; Ou, WH; Chen, Longbao; Han, Jie] Guizhou Normal Univ, Sch Big Data & Comp Sci, Guiyang 550025, Peoples R China.;[Zeng, Wu] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430000, Peoples R China.;[Gou, Jianping] Southwest Univ, Coll Comp & Informat Sci, Coll Software, Chongqing 400715, Peoples R China.
通讯机构：
[Ou, WH ] G;Guizhou Normal Univ, Sch Big Data & Comp Sci, Guiyang 550025, Peoples R China.
关键词：
Face video;Heart rate;Remote photoplethysmography;Group sparse representation
摘要：
Non-contact heart rate measurement based on face video is rapidly developed due to its comfort and wide application. However, it is difficult to extract the pulse signals for non-contact heart rate measurement due to the various interference factors, such as illumination variation, head motion and face expression. In this paper, we propose group sparse representation to reconstruct the pulse signals, then estimate the heart rate based on the fact that the real heart rate is consistent at the same time from different sub-regions. Specifically, we formulate the reconstruction of pulse signals as group sparse representation problem and require the raw signals of all the sub-regions to be similar sparse representation. Firstly, we use the face detection algorithm to obtain the region of interest (ROI) and divide it into sub-regions, followed by the distortion compensation of color signals from different sub-regions. Then we extract the sub-region chrominance signals and select the high-quality chrominance signals to construct the raw pulse signals matrix. After that, we construct a mixed pulse dictionary containing discrete cosine bases and wavelet bases considering the periodicity and pulsatility of the pulse signals. Finally, we conduct group sparse representation to reconstruct the pulse signals and estimate the heart rate via spectral analysis based on the reconstructed pulse signals. Experimental results on three public datasets show that this method outperforms most existing heart rate measurement methods.
摘要：
The magnetization and magnetostriction properties of Mn1_xMgxV2O4 (x = 0.00, 0.10, 0.15, 0.20) single crystals have been investigated under both static and pulsed magnetic fields, in which the magnetization and magnetostriction behaviors exhibit field-sweep-rate dependence, which are related to the spin-orbital-lattice coupling in these systems. Especially, anomalous enhancement of spin-orbital correlation was observed for x = 0.15. We attribute this enhancement to the tuning on the canting angle of V3+ ions by Mg2+-ions substitution. Furthermore, while the inter-vanadium distance RV-V is important to determine the evolution of the properties in the doped cases proposed by many studies, our result suggests that RV-V is not always dominant, the spin-orbital correlation effect can survive from the disordering induced by the variation of RV-V and even be enhanced at proper doping level.
摘要：
Wireless sensor networks (WSNs) are mostly used for monitoring the environment; however, they are usually powered by non-rechargeable batteries with limited energy. Solar energy harvesting is an attractive solution to the limit by charging the sensor nodes; however, the harvested solar energy is easily affected by weather conditions. Based on the characteristics of uncertainty and intermittency of solar energy, this paper proposes a plus-profile solar energy prediction algorithm. This algorithm makes the prediction of future available solar energy by finding the data in the dataset that is most similar to the data of the day and combining it with recent weather trend. According to the predicted result, the paper further proposes an adaptive energy management scheme to suit the harvested energy. In the scheme, sensor nodes can adaptively adjust task scheduling to achieve energy neutrality. The simulation results show that compared with other algorithms, the prediction accuracy of the proposed prediction algorithm is improved by 17.7 and 22.4%, respectively, and the proposed energy management scheme reduced energy loss by 6.2 and 46.8%, respectively.
作者：
Fang, Chao;Chen, Xiqu;Zhang, Juanjuan;Xia, Xiaodong;Weng, George J.
期刊：
Journal of Physics D: Applied Physics,2023年56(4):045301 ISSN：0022-3727
通讯作者：
George J Weng
作者机构：
[Fang, Chao; Chen, Xiqu] Wuhan Polytech Univ, Dept Elect & Elect Engn, Wuhan 430023, Hubei, Peoples R China.;[Zhang, Juanjuan] Lanzhou Univ, Key Lab Mech Environm & Disaster Western China, Minist Educ China, Lanzhou 730000, Gansu, Peoples R China.;[Zhang, Juanjuan] Lanzhou Univ, Coll Civil Engn & Mech, Dept Mech & Engn Sci, Lanzhou 730000, Gansu, Peoples R China.;[Xia, Xiaodong] Cent South Univ, Sch Civil Engn, Changsha 410083, Peoples R China.;[Weng, George J.] Rutgers State Univ, Dept Mech & Aerosp Engn, New Brunswick, NJ 08903 USA.
通讯机构：
[George J Weng] D;Department of Mechanical and Aerospace Engineering, Rutgers University, New Brunswick, NJ 08903, United States of America
关键词：
graphene films;EMI shielding;electromagnetic plane wave;path;wrinkles;Monte Carlo
摘要：
In this paper, the electromagnetic interference shielding effectiveness (EMI SE) of multilayer graphene films is studied by the Monte Carlo (MC) method. First, we use the transfer matrix method to study the transmission and reflection of electric fields of the incident light passing through the graphene plane and the dielectric interface, and then determine the reflection and transmission probability of the light. In this way, the path of light can be obtained by the MC method. From the distance and emission direction of a large number of lights passing through the film, the expected value of the emitted light field is calculated and the EMI SE is determined. The obtained results of SE are shown to be in good agreement with several sets of experimental data. This model also takes into account the influence of wrinkles of graphene. It is found that EMI SE first increases and then decreases with the increase of wrinkle. The effects of film thickness, conductivity, and dielectric constant on EMI SE in the X-band frequency range are also investigated.
通讯机构：
[Lei, C; Liu, S ] W;Wuhan Univ, Inst Technol Sci, Wuhan 430072, Peoples R China.;Wuhan Univ, Sch Power & Mech Engn, Wuhan 430072, Peoples R China.
关键词：
RF compression cavity;dynamic atomic motion;ultrafast electron diffraction
摘要：
Ultrafast electron diffraction (UED) is a powerful tool for observing the evolution of transient structures at the atomic level. However, temporal resolution is a huge challenge for UEDs, mainly depending on the pulse duration. Unfortunately, the Coulomb force between electrons causes the pulse duration to increase continually when propagating, reducing the temporal resolution. In this paper, we theoretically design a radio frequency (RF) compression cavity using the finite-element method of electromagnetic-thermal coupling to overcome this limitation and obtain a high-brightness, short-pulse-duration, and stable electron beam. In addition, the cavity's size parameters are optimized, and a water-cooling system is designed to ensure stable operation. To the best of our knowledge, this is the first time that the electromagnetic-thermal coupling method has been used to study the RF cavity applied to UED. The results show that the RF cavity operates in TM010 mode with a resonant frequency of 2970 MHz and generates a resonant electric field. This mode of operation generates an electric field that varies periodically and transiently, compressing the electronic pulse duration. The electromagnetic-thermal coupling method proposed in this study effectively improves the temporal resolution of UED.
摘要：
Multipartite nonlocality is a measure of multipartite quantum correlations. In this paper we investigate the influence of symmetry-breaking perturbations upon ground-state nonlocality by considering several typical finite-size quantum models, including the transverse-field Ising chains, the XY ( XX ) chains, and the XXZ chains. We find that even a slight perturbation can reshape the nonlocality curve dramatically. For instance, in the XY chains, a perturbation can induce an oscillation behavior in the nonlocality curve. A clear microscopic mechanism for the results is proposed. Furthermore, we also connect the behaviors to the macroscopic symmetry properties of the chains and make some predictions on general models.
摘要：
The structural, electronic and optical properties of MoSSe, PbS (111) and MoSSe/PbS (111) have been studied by the first-principles calculations, and the effect of V(S)on electronic and optical properties of MoSSe/PbS (111). When PbS (111) is stacked on MoSSe, an internal electric field and ohmic contact are formed at interlayer, and exhibited metal property. Compared with MoSSe and PbS (111) monolayer, MoSSe/PbS (111) heterostructure has higher absorption coefficients. Further analysis shows that this can be attributed to the orbital hybridization between the heterostructure layers. When V(S)is introduced, spin splitting occurs, making the spin-down channel below the Fermi level and inducing half-metallicity. What's more, Vs MoSSe/PbS (111) still performances better optical absorption coefficient. Based on these findings, the heterogeneous structures and defects not only affect the electronic properties, but also can be used as an effective method to regulate the electrical and optical properties, providing useful theoretical guidance for further experimental studies.
作者机构：
[Zhao, Xu; Li, Shaozhen] Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;[Wu, Sujuan; Zhong, Shoudeng; Wu, SJ; Wang, Shuqi] South China Normal Univ, Inst Adv Mat, South China Acad Adv Optoelect, Guangzhou 510006, Peoples R China.;[Wu, Sujuan; Zhong, Shoudeng; Wu, SJ; Wang, Shuqi] South China Normal Univ, South China Acad Adv Optoelect, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Peoples R China.
通讯机构：
[Wu, SJ ] S;[Li, SZ ] W;Wuhan Polytech Univ, Sch Elect & Elect Engn, Wuhan 430023, Peoples R China.;South China Normal Univ, Inst Adv Mat, South China Acad Adv Optoelect, Guangzhou 510006, Peoples R China.;South China Normal Univ, South China Acad Adv Optoelect, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Peoples R China.
关键词：
potassium thiocyanate;diluted PEDOT:PSS solution;tin-based perovskite solar cells;photovoltaic performance
摘要：
The commercialized poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) is usually used as hole transport layers (HTLs) in tin-based perovskite solar cells (TPSCs). However, the further development has been restricted due to the acidity that could damage the stability of TPSCs. Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication, the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution. Herein, potassium thiocyanate (KSCN) is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs. The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied. At the optimal KSCN concentration, the TPSCs based on KSCN-doped PEDOT:PSS HTLs (KSCN-PSCs) demonstrate the champion power conversion efficiency (PCE) of 8.39%, while the reference TPSCs only show a champioan PCE of 6.70%. The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution, improves the microstructure of perovskite film, and inhibits carrier recombination in TPSCs, leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs. This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PE-DOT:PSS aqueous solution for efficient TPSCs.
