A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their inter...A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high robustness.During the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and Cm.In the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.展开更多
Compared to organic-inorganic hybrid perovskites,the cesium-based allinorganic lead halide perovskite(CsPbI_(3))is a promising light absorber for perovskite solar cells owing to its higher resistance to thermal stress...Compared to organic-inorganic hybrid perovskites,the cesium-based allinorganic lead halide perovskite(CsPbI_(3))is a promising light absorber for perovskite solar cells owing to its higher resistance to thermal stress.Nonetheless,additional research is required to reduce the nonradiative recombination to realize the full potential of CsPbI_(3).Here,the diffusion of Cs ions participating in ion exchange is proposed to be an important factor responsible for the bulk defects inγ-CsPbI_(3)perovskite.Calculations based on first-principles density functional theory reveal that the[PbI_(6)]^(4-)octahedral tilt modifies the perovskite crystallographic properties inγ-CsPbI_(3),leading to alterations in its bandgap and crystal strain.In addition,by substituting amorphous barium titanium oxide(a-BaTiO_(3))for TiO_(2)as the electron transport layer,interfacial defects caused by imperfect energy levels between the electron transport layer and perovskite are reduced.High-resolution transmission electron microscopy and electron energy loss spectroscopy demonstrate that a-BaTiO_(3)forms entirely as a single phase,as opposed to Ba-doped TiO_(2)hybrid nanoclusters or separate domains of TiO_(2)and BaTiO_(3)phases.Accordingly,inorganic perovskite solar cells based on the a-BaTiO_(3)electron transport layer achieved a power conversion efficiency of 19.96%.展开更多
To insight into the B-site ordering in RFe_(0.5)Cr_(0.5)O_(3)ceramics,a series of RFe_(0.5)Cr_(0.5)O_(3)ceramics(R=La,Y,Lu)were synthesized by the sol-gel method,and the structural and magnetic properties were systemi...To insight into the B-site ordering in RFe_(0.5)Cr_(0.5)O_(3)ceramics,a series of RFe_(0.5)Cr_(0.5)O_(3)ceramics(R=La,Y,Lu)were synthesized by the sol-gel method,and the structural and magnetic properties were systemically investigated.By using the Rietveld refinement of all samples,it is found that the structural distortion is increased as the R ionic radius decreases,leading to the weakened interactions between Fe/Cr ions.Moreover,the Fe and Cr are arranged in disorder in LaFe_(0.5)Cr_(0.5)O_(3),but partially ordered in YFe_(0.5)Cr_(0.5)O_(3)and LuFe_(0.5)Cr_(0.5)O_(3),showing an increasing trend of the proportion of ordered domains with the decrease of R ionic radius.Through fitting the temperature-dependent magnetizations,it is identified that the magnetization reversal(MR)in disorder LaFe_(0.5)Cr_(0.5)O_(3)is resulted from the competition between the moments of Cr and Fe sublattices.In the partially ordered YFe_(0.5)Cr_(0.5)O_(3)and LuFe_(0.5)Cr_(0.5)O_(3)ceramics,because of the presence of Fe-O-Cr networks in the ordered domains whose moment is antiparallel to that of Fe-O-Fe and Cr-O-Cr in the disordered domains,the compensation temperature T_(comp)of MR is increased by nearly 50 K.These results suggest that the changing of R-site ions could be used very effectively to modify the Fe-O-Cr ordering,apart from the structural distortion,which has a direct effect on the magnetic exchange interactions in RFe_(0.5)Cr_(0.5)O_(3)ceramics.Then at values of composition where ordered domains are expected to be larger in number as compared to disordered domains and with a weaker structural distortion,one can expect a higher transition temperature Tcomp,providing a different view for adjustment of the magnetic properties of RFe_(0.5)Cr_(0.5)O_(3)ceramics for practical applications.展开更多
基金Funded by the National Key Research and Development Program of China(No.2023YFB3812200)。
文摘A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high robustness.During the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and Cm.In the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)granted financial resource from the Ministry of Trade,Industry&Energy,Republic of Korea(20213091010020)the Korea Institute of Planning and Evaluation for Technology in Food,Agriculture and Forestry(IPET)and Korea Smart Farm R&D Foundation(KosFarm)through Smart Farm Innovation Technology Development Programfunded by Ministry of Agriculture,Food and Rural Affairs(MAFRA),Ministry of Science and ICT(MSIT),Rural Development Administration(RDA)(421036-03)
文摘Compared to organic-inorganic hybrid perovskites,the cesium-based allinorganic lead halide perovskite(CsPbI_(3))is a promising light absorber for perovskite solar cells owing to its higher resistance to thermal stress.Nonetheless,additional research is required to reduce the nonradiative recombination to realize the full potential of CsPbI_(3).Here,the diffusion of Cs ions participating in ion exchange is proposed to be an important factor responsible for the bulk defects inγ-CsPbI_(3)perovskite.Calculations based on first-principles density functional theory reveal that the[PbI_(6)]^(4-)octahedral tilt modifies the perovskite crystallographic properties inγ-CsPbI_(3),leading to alterations in its bandgap and crystal strain.In addition,by substituting amorphous barium titanium oxide(a-BaTiO_(3))for TiO_(2)as the electron transport layer,interfacial defects caused by imperfect energy levels between the electron transport layer and perovskite are reduced.High-resolution transmission electron microscopy and electron energy loss spectroscopy demonstrate that a-BaTiO_(3)forms entirely as a single phase,as opposed to Ba-doped TiO_(2)hybrid nanoclusters or separate domains of TiO_(2)and BaTiO_(3)phases.Accordingly,inorganic perovskite solar cells based on the a-BaTiO_(3)electron transport layer achieved a power conversion efficiency of 19.96%.
基金supported by the Natural Science Foundation of Henan Province,China(Grant Nos.232300420353 and 232300420392)the Key Scientific Research Project of Higher Education of Henan Province(Grant No.24B140001)+2 种基金the Doctor Scientific Research Initiate Fund of Anyang Institute of Technology(Grant No.BSJ2022010)the National Basic Research Program of China(Grant No.2009CB939901)the Henan Provincial Science and Technology Research Project(Grant No.232102241016).
文摘To insight into the B-site ordering in RFe_(0.5)Cr_(0.5)O_(3)ceramics,a series of RFe_(0.5)Cr_(0.5)O_(3)ceramics(R=La,Y,Lu)were synthesized by the sol-gel method,and the structural and magnetic properties were systemically investigated.By using the Rietveld refinement of all samples,it is found that the structural distortion is increased as the R ionic radius decreases,leading to the weakened interactions between Fe/Cr ions.Moreover,the Fe and Cr are arranged in disorder in LaFe_(0.5)Cr_(0.5)O_(3),but partially ordered in YFe_(0.5)Cr_(0.5)O_(3)and LuFe_(0.5)Cr_(0.5)O_(3),showing an increasing trend of the proportion of ordered domains with the decrease of R ionic radius.Through fitting the temperature-dependent magnetizations,it is identified that the magnetization reversal(MR)in disorder LaFe_(0.5)Cr_(0.5)O_(3)is resulted from the competition between the moments of Cr and Fe sublattices.In the partially ordered YFe_(0.5)Cr_(0.5)O_(3)and LuFe_(0.5)Cr_(0.5)O_(3)ceramics,because of the presence of Fe-O-Cr networks in the ordered domains whose moment is antiparallel to that of Fe-O-Fe and Cr-O-Cr in the disordered domains,the compensation temperature T_(comp)of MR is increased by nearly 50 K.These results suggest that the changing of R-site ions could be used very effectively to modify the Fe-O-Cr ordering,apart from the structural distortion,which has a direct effect on the magnetic exchange interactions in RFe_(0.5)Cr_(0.5)O_(3)ceramics.Then at values of composition where ordered domains are expected to be larger in number as compared to disordered domains and with a weaker structural distortion,one can expect a higher transition temperature Tcomp,providing a different view for adjustment of the magnetic properties of RFe_(0.5)Cr_(0.5)O_(3)ceramics for practical applications.
