Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2636/1/012048
Zhiwei He, Enlong Wen, Tao Wang, Chao Huang, Shujie Li, Ruhua Cai
Abstract In order to study the condensation and heat transfer characteristics of similar microstructure surfaces, two similar microstructure surfaces, cylindrical and circular, were fabricated by femtosecond laser technology on a 0.5 mm silicon wafer. The cylindrical surface is superhydrophobic when the contact angle is more than 150°, and the circular surface is hydrophilic when the contact angle is less than 90°. The difference in condensation heat transfer characteristics between superhydrophobic and hydrophilic microstructures was analyzed, and a visual condensation experimental platform was built. Experimental research showed that: At the same flow rate, the heat transfer coefficient of the superhydrophobic surface and the hydrophilic surface decreases significantly with the increase of the surface subcooling degree, but the heat transfer coefficient of the cylindrical surface is still much larger than that of the circular surface. In addition, the heat transfer performance of the hydrophobic microstructure surface is better than that of the hydrophilic surface at medium and high-speed cooling water flow rates. Although the surface microstructures are similar in shape, the heat transfer performance of cylindrical microstructures is much better than that of circular microstructures under the same conditions, and the heat flux of cylindrical microstructures is 2.2 times that of circular microstructures.
{"title":"Experimental Study on Condensation Heat Transfer Performance of Hydrophilic/Hydrophobic Microstructured","authors":"Zhiwei He, Enlong Wen, Tao Wang, Chao Huang, Shujie Li, Ruhua Cai","doi":"10.1088/1742-6596/2636/1/012048","DOIUrl":"https://doi.org/10.1088/1742-6596/2636/1/012048","url":null,"abstract":"Abstract In order to study the condensation and heat transfer characteristics of similar microstructure surfaces, two similar microstructure surfaces, cylindrical and circular, were fabricated by femtosecond laser technology on a 0.5 mm silicon wafer. The cylindrical surface is superhydrophobic when the contact angle is more than 150°, and the circular surface is hydrophilic when the contact angle is less than 90°. The difference in condensation heat transfer characteristics between superhydrophobic and hydrophilic microstructures was analyzed, and a visual condensation experimental platform was built. Experimental research showed that: At the same flow rate, the heat transfer coefficient of the superhydrophobic surface and the hydrophilic surface decreases significantly with the increase of the surface subcooling degree, but the heat transfer coefficient of the cylindrical surface is still much larger than that of the circular surface. In addition, the heat transfer performance of the hydrophobic microstructure surface is better than that of the hydrophilic surface at medium and high-speed cooling water flow rates. Although the surface microstructures are similar in shape, the heat transfer performance of cylindrical microstructures is much better than that of circular microstructures under the same conditions, and the heat flux of cylindrical microstructures is 2.2 times that of circular microstructures.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"30 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135764053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Projection-based multimodal 3D semantic segmentation methods suffer from information loss during the point cloud projection process. This issue becomes more prominent for small objects. Moreover, the alignment of sparse target features with the corresponding object features in the camera image during the fusion process is inaccurate, leading to low segmentation accuracy for small objects. Therefore, we propose an attention-based multimodal feature alignment and fusion network module. This module aggregates features in spatial directions and generates attention matrices. Through this transformation, the module could capture remote dependencies of features in one spatial direction. This helps our network precisely locate objects and establish relationships between similar features. It enables the adaptive alignment of sparse target features with the corresponding object features in the camera image, resulting in a better fusion of the two modalities. We validate our method on the nuScenes-lidar seg dataset. Our CAFNet achieves an improvement in segmentation accuracy for small objects with fewer points compared to the baseline network, such as bicycles (6% improvement), pedestrians (2.1% improvement), and traffic cones (0.9% improvement).
{"title":"RGB and LiDAR Fusion-based 3D Semantic Segmentation for Autonomous Driving","authors":"Jianguo Liu, Zhiling Jia, Gongbo Li, Fuwu Yan, Youhua Wu, Yunfei Sun","doi":"10.1088/1742-6596/2632/1/012034","DOIUrl":"https://doi.org/10.1088/1742-6596/2632/1/012034","url":null,"abstract":"Abstract Projection-based multimodal 3D semantic segmentation methods suffer from information loss during the point cloud projection process. This issue becomes more prominent for small objects. Moreover, the alignment of sparse target features with the corresponding object features in the camera image during the fusion process is inaccurate, leading to low segmentation accuracy for small objects. Therefore, we propose an attention-based multimodal feature alignment and fusion network module. This module aggregates features in spatial directions and generates attention matrices. Through this transformation, the module could capture remote dependencies of features in one spatial direction. This helps our network precisely locate objects and establish relationships between similar features. It enables the adaptive alignment of sparse target features with the corresponding object features in the camera image, resulting in a better fusion of the two modalities. We validate our method on the nuScenes-lidar seg dataset. Our CAFNet achieves an improvement in segmentation accuracy for small objects with fewer points compared to the baseline network, such as bicycles (6% improvement), pedestrians (2.1% improvement), and traffic cones (0.9% improvement).","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"92 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135716780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2632/1/012018
Xiong Lv, Baoge Zhang, Hao Tian, Yongquan Ren, Fuhong Cui
Abstract Due to the differences in the line resistance of each distributed generation unit, conventional sag control does not allow for precise distribution of power, which also reduces the problem of system reactive power accuracy. To address this problem, this paper analyzes the power equalization and distribution conditions. A method for adaptive adjustment of virtual resistance by system output power feedback is submitted. Reducing the variance among the original line resistances aims to solve the problem of power not being evenly divided and improve the equalization of reactive power. By building a Simulink parallel simulation model of the inverter, it is verified that the power feedback-based fetching and the improved droop control is effective.
{"title":"Power Equalization Strategy Based on Adaptive Virtual Impedance","authors":"Xiong Lv, Baoge Zhang, Hao Tian, Yongquan Ren, Fuhong Cui","doi":"10.1088/1742-6596/2632/1/012018","DOIUrl":"https://doi.org/10.1088/1742-6596/2632/1/012018","url":null,"abstract":"Abstract Due to the differences in the line resistance of each distributed generation unit, conventional sag control does not allow for precise distribution of power, which also reduces the problem of system reactive power accuracy. To address this problem, this paper analyzes the power equalization and distribution conditions. A method for adaptive adjustment of virtual resistance by system output power feedback is submitted. Reducing the variance among the original line resistances aims to solve the problem of power not being evenly divided and improve the equalization of reactive power. By building a Simulink parallel simulation model of the inverter, it is verified that the power feedback-based fetching and the improved droop control is effective.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135716788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2636/1/012033
Rui Su, Yiming Zhang, Dong Zhang, Junxia Gao
Abstract This paper takes the time-domain aeromagnetic system as the research object and uses the finite element software COMSOL Multiphysics 6.0 to establish the three-dimensional system model. By comparing the COMSOL Multiphysics forward simulation solution with the one-dimensional numerical solution, it verifies that the COMSOL software meets the simulation accuracy requirements of the three-dimensional time-domain aeromagnetic method, and focuses on the analysis of the transient response at different flight altitudes is also analyzed. Based on the analysis of this paper, a set of aeromagnetic parameters with high detection capability is determined for engineering practice, and a test of the system is completed.
{"title":"Simulation Analysis Based on COMSOL Helicopter Time-domain Aeromagnetic Method","authors":"Rui Su, Yiming Zhang, Dong Zhang, Junxia Gao","doi":"10.1088/1742-6596/2636/1/012033","DOIUrl":"https://doi.org/10.1088/1742-6596/2636/1/012033","url":null,"abstract":"Abstract This paper takes the time-domain aeromagnetic system as the research object and uses the finite element software COMSOL Multiphysics 6.0 to establish the three-dimensional system model. By comparing the COMSOL Multiphysics forward simulation solution with the one-dimensional numerical solution, it verifies that the COMSOL software meets the simulation accuracy requirements of the three-dimensional time-domain aeromagnetic method, and focuses on the analysis of the transient response at different flight altitudes is also analyzed. Based on the analysis of this paper, a set of aeromagnetic parameters with high detection capability is determined for engineering practice, and a test of the system is completed.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"22 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2636/1/012002
Rong Yao Sun, Lei Mao
Abstract In order to ensure the safe operation of lithium-ion batteries, real-time monitoring of battery status is necessary. The surface strain signal of lithium-ion batteries has the potential to evaluate the battery’s state, but it is significantly affected by temperature. Generally, measuring the battery surface temperature and the thermal expansion coefficient can be performed to quantify and eliminate the influence of temperature on strain, but this increases the cost and complexity of strain measurement. This article proposes a method that eliminates the need to measure the battery temperature and material parameters. By simultaneously measuring the circumferential and axial strains on the battery surface and calculating their difference, the influence of temperature on strain can be minimized. Furthermore, the effectiveness of the proposed method is experimentally tested. Results demonstrate that after applying temperature compensation to commercial lithium-ion batteries, the influence of temperature on strain can be reduced from 16.4 ppm/°C to 1.7 ppm/°C. The strain no longer exhibits sensitivity to current, making it more suitable for evaluating the state of lithium-ion batteries.
{"title":"A Novel Temperature Compensation Method for Surface Strain of Cylindrical Lithium-ion Batteries","authors":"Rong Yao Sun, Lei Mao","doi":"10.1088/1742-6596/2636/1/012002","DOIUrl":"https://doi.org/10.1088/1742-6596/2636/1/012002","url":null,"abstract":"Abstract In order to ensure the safe operation of lithium-ion batteries, real-time monitoring of battery status is necessary. The surface strain signal of lithium-ion batteries has the potential to evaluate the battery’s state, but it is significantly affected by temperature. Generally, measuring the battery surface temperature and the thermal expansion coefficient can be performed to quantify and eliminate the influence of temperature on strain, but this increases the cost and complexity of strain measurement. This article proposes a method that eliminates the need to measure the battery temperature and material parameters. By simultaneously measuring the circumferential and axial strains on the battery surface and calculating their difference, the influence of temperature on strain can be minimized. Furthermore, the effectiveness of the proposed method is experimentally tested. Results demonstrate that after applying temperature compensation to commercial lithium-ion batteries, the influence of temperature on strain can be reduced from 16.4 ppm/°C to 1.7 ppm/°C. The strain no longer exhibits sensitivity to current, making it more suitable for evaluating the state of lithium-ion batteries.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"23 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2632/1/012031
Hongyue Zhang, Jie Chang
Abstract In the process of digital transformation of rail transit vehicles, the digitalization of production line equipment is an important content. Starting from the whole life cycle business of production line equipment, this paper improves the existing production line equipment index system, proposes the production line equipment data acquisition model, describes the equipment portrait, proposes the comprehensive evaluation system based on the equipment index model, and further explores the digital twin architecture of production line equipment based on the integration of multiple models. Improve the digital level of rail transit vehicle manufacturing production line equipment.
{"title":"Digitization of production line equipment of rail transit vehicles based on index and model","authors":"Hongyue Zhang, Jie Chang","doi":"10.1088/1742-6596/2632/1/012031","DOIUrl":"https://doi.org/10.1088/1742-6596/2632/1/012031","url":null,"abstract":"Abstract In the process of digital transformation of rail transit vehicles, the digitalization of production line equipment is an important content. Starting from the whole life cycle business of production line equipment, this paper improves the existing production line equipment index system, proposes the production line equipment data acquisition model, describes the equipment portrait, proposes the comprehensive evaluation system based on the equipment index model, and further explores the digital twin architecture of production line equipment based on the integration of multiple models. Improve the digital level of rail transit vehicle manufacturing production line equipment.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"52 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A combined time-series-based regression forecasting and GRA-IPSO-BP structure is proposed to forecast the electricity replacement forecasts using a time series model based on the triple exponential smoothing forecasting method. The forecast results are corrected using the GRA-IPSO-BP structure. The results of the algorithm show that using a combination of time series and GRA-IPSO-BP structure can significantly improve the forecasting accuracy of electricity replacement compared to single-method forecasting.
{"title":"Regional electrical energy substitution potential prediction based on time series and improved back propagation neural network","authors":"Ziwen Cai, Yutao Xu, Yong Xiao, Dunhui Chen, Yun Zhao, Zhukui Tan","doi":"10.1088/1742-6596/2636/1/012029","DOIUrl":"https://doi.org/10.1088/1742-6596/2636/1/012029","url":null,"abstract":"Abstract A combined time-series-based regression forecasting and GRA-IPSO-BP structure is proposed to forecast the electricity replacement forecasts using a time series model based on the triple exponential smoothing forecasting method. The forecast results are corrected using the GRA-IPSO-BP structure. The results of the algorithm show that using a combination of time series and GRA-IPSO-BP structure can significantly improve the forecasting accuracy of electricity replacement compared to single-method forecasting.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"28 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2623/1/012005
N Chairunnisa, N H Haryanti, R Nurwidayati, A Y Pratiwi, Y Arnandha, Y Saputra, N Hazizah
Abstract Fly ash waste from the Asam-Asam Power Plant in South Kalimantan continues to increase. Various attempts have been made to utilize fly ash waste, among others. as a basic material for making geopolymers. Geopolymer is environmentally friendly because it replaces all cement with high Silica (Si) and Alumina (Al) wastes such as fly ash. This study aims to characterize fly ash as a raw material of geopolymer. Fly ash was filtered using 200 mesh and then heated in an oven at 105°C for 24 hours. The prepared fly ash was then tested for physical properties and compound analysis using XRF, identification of chemical bonds and functional groups using FTIR, morphology, and elements using SEM EDX. Initial and final setting time was investigated using the Vicat apparatus to determine e whether cement is undergoing proper hydration. The results indicated that the fly ash was classified to class F. That was based on the amount of SiO 2 + Al 2 O 3 + Fe 2 O 3 of 85.91%, and the CaO content was less than 10%. Moreover, fly ash’s initial and final setting time was 1072.5 and 3180 minutes, respectively. Fly ash in this research can be used as a raw material for geopolymers.
{"title":"Characteristics of Fly Ash as a Constituent Material for Geopolymer","authors":"N Chairunnisa, N H Haryanti, R Nurwidayati, A Y Pratiwi, Y Arnandha, Y Saputra, N Hazizah","doi":"10.1088/1742-6596/2623/1/012005","DOIUrl":"https://doi.org/10.1088/1742-6596/2623/1/012005","url":null,"abstract":"Abstract Fly ash waste from the Asam-Asam Power Plant in South Kalimantan continues to increase. Various attempts have been made to utilize fly ash waste, among others. as a basic material for making geopolymers. Geopolymer is environmentally friendly because it replaces all cement with high Silica (Si) and Alumina (Al) wastes such as fly ash. This study aims to characterize fly ash as a raw material of geopolymer. Fly ash was filtered using 200 mesh and then heated in an oven at 105°C for 24 hours. The prepared fly ash was then tested for physical properties and compound analysis using XRF, identification of chemical bonds and functional groups using FTIR, morphology, and elements using SEM EDX. Initial and final setting time was investigated using the Vicat apparatus to determine e whether cement is undergoing proper hydration. The results indicated that the fly ash was classified to class F. That was based on the amount of SiO 2 + Al 2 O 3 + Fe 2 O 3 of 85.91%, and the CaO content was less than 10%. Moreover, fly ash’s initial and final setting time was 1072.5 and 3180 minutes, respectively. Fly ash in this research can be used as a raw material for geopolymers.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"28 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2636/1/012008
Zhiru Chen, Xi Zhao, Zhi Zhang, Zhen Jing
Abstract Based on the design theory that products can be assembled, the optimal design of the electric energy metering box in the embedded copper bar and other aspects is realized, the product wiring is standardized and concealed, the assembly method is optimized, the assembly difficulty is greatly reduced, several problems in cost and quality are solved in industrial design, and objective score data from experts are obtained through perceptual experiments. It provides a new design method and evaluation idea for the field of power measurement and has great popularization value.
{"title":"Design and engineering application of a new type of copper bar-embedded metering box based on DFA theory","authors":"Zhiru Chen, Xi Zhao, Zhi Zhang, Zhen Jing","doi":"10.1088/1742-6596/2636/1/012008","DOIUrl":"https://doi.org/10.1088/1742-6596/2636/1/012008","url":null,"abstract":"Abstract Based on the design theory that products can be assembled, the optimal design of the electric energy metering box in the embedded copper bar and other aspects is realized, the product wiring is standardized and concealed, the assembly method is optimized, the assembly difficulty is greatly reduced, several problems in cost and quality are solved in industrial design, and objective score data from experts are obtained through perceptual experiments. It provides a new design method and evaluation idea for the field of power measurement and has great popularization value.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"27 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1088/1742-6596/2623/1/012002
R K Pingak, A Z Johannes, N U J Hauwali, U A Deta
Abstract This study investigates the structural parameters and the electronic properties of cubic TlGeCl x Br 3-x (x=0,1,2,3) lead-free perovskites to evaluate their potential as absorbers in perovskite solar cell devices. Density Functional Theory (DFT) embedded in the Quantum Espresso code was used to calculate these properties. The results revealed that the compounds have optimized lattice constants of 5.244 Å, 5.336 Å, 5.416 Å, and 5.501 Å, for TlGeCl 3 , TlGeCl 2 Br, TlGeClBr 2 , and TlGeBr 3 perovskites, respectively. In addition, the compounds are direct band gap (R → R) semiconductors with energy gap values of 0.847 eV, 0.683 eV, 0.556 eV, and 0.518 eV for the respective materials. It is important to note that the band gap of the perovskites reduces as a Cl − ion, two and three Cl − ions are replaced by a Br − ion, two and three Br − ions, respectively. The analysis of their projected density of states indicated that near the valence band maximum of the perovskites, Cl-3p and Br-4p states contributes the most to their total DOS. In contrast, the Ge-4p orbital is the most dominant state close to the conduction band minimum. Based on these energy gap values, the studied materials are promising candidates for lead-free perovskite solar cell devices, with TlGeBr 3 projected to be more promising than the other three materials.
{"title":"Lead-free Perovskites TlGeCl<sub>x</sub>Br<sub>3-x</sub> (x=0,1,2,3) as Promising Materials for Solar Cell Application: a DFT Study","authors":"R K Pingak, A Z Johannes, N U J Hauwali, U A Deta","doi":"10.1088/1742-6596/2623/1/012002","DOIUrl":"https://doi.org/10.1088/1742-6596/2623/1/012002","url":null,"abstract":"Abstract This study investigates the structural parameters and the electronic properties of cubic TlGeCl x Br 3-x (x=0,1,2,3) lead-free perovskites to evaluate their potential as absorbers in perovskite solar cell devices. Density Functional Theory (DFT) embedded in the Quantum Espresso code was used to calculate these properties. The results revealed that the compounds have optimized lattice constants of 5.244 Å, 5.336 Å, 5.416 Å, and 5.501 Å, for TlGeCl 3 , TlGeCl 2 Br, TlGeClBr 2 , and TlGeBr 3 perovskites, respectively. In addition, the compounds are direct band gap (R → R) semiconductors with energy gap values of 0.847 eV, 0.683 eV, 0.556 eV, and 0.518 eV for the respective materials. It is important to note that the band gap of the perovskites reduces as a Cl − ion, two and three Cl − ions are replaced by a Br − ion, two and three Br − ions, respectively. The analysis of their projected density of states indicated that near the valence band maximum of the perovskites, Cl-3p and Br-4p states contributes the most to their total DOS. In contrast, the Ge-4p orbital is the most dominant state close to the conduction band minimum. Based on these energy gap values, the studied materials are promising candidates for lead-free perovskite solar cell devices, with TlGeBr 3 projected to be more promising than the other three materials.","PeriodicalId":44008,"journal":{"name":"Journal of Physics-Photonics","volume":"30 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}