The aim of the work was the study of the effect of NEMP (nanosecond electromagnetic pulses) on steel properties. Steel treatment was performed under the workshop conditions. The mechanical properties and the microst...The aim of the work was the study of the effect of NEMP (nanosecond electromagnetic pulses) on steel properties. Steel treatment was performed under the workshop conditions. The mechanical properties and the microstructure of the experimental samples and samples prepared by usual way were analyzed. The treatment of metal melt with nanosecond electromagnetic pulses at the crystallization stage makes it possible to change mechanical properties of metal and its structure.展开更多
It has been experimentally demonstrated that the stereometric packings of two new bisPC_(71) BM isomers have an important impact on the power conversion efficiency of organic solar cells. Here, a theoretical investiga...It has been experimentally demonstrated that the stereometric packings of two new bisPC_(71) BM isomers have an important impact on the power conversion efficiency of organic solar cells. Here, a theoretical investigation is made to reveal the mechanism behind from detailed photophysical processes in performed cells. The results show that the crystal packings of isomers affect the electron mobilities dominantly from the electronic coupling for electron transfer, and the trends of calculated mobilities are consistent with experimental measurements although the magnitudes are obviously larger. For the performed cells from two isomers with poly(3-hexylthiophene) as a donor, it is found that the exciton dissociation yields are also different, manifesting that stereometric packings essentially control the cell efficiency via both electron mobilities and exciton dissociation. Furthermore,the reasons for low cell efficiencies are analyzed, and possible improvements are suggested.展开更多
Organic electron acceptor materials play an important role in organic electronics.Recently,many organic electron acceptors have been developed,in which aromatic fused-imides have proved to be a promising family of exc...Organic electron acceptor materials play an important role in organic electronics.Recently,many organic electron acceptors have been developed,in which aromatic fused-imides have proved to be a promising family of excellent electron acceptors.We report the first synthesis of a novel aromatic fused-imide,acenaphtho[1,2-k]fluoranthene diimide derivative(AFI),using lithium-halogen exchange and Diels-Alder reactions.The construction of a large conjugated plane and the introduction of electron-withdrawing imide groups endow AFI with a low lowest unoccupied molecular orbital(LUMO)level of 3.80 e V.AFI exhibits a regular molecular arrangement and strong - interactions in the single-crystal structure,which indicates its potential application in organic electronic devices.Solar cell devices that were fabricated using AFI as the electron acceptor and P3HT as the electron donor achieved an energy conversion efficiency of 0.33%.展开更多
Top-contact organic field effect transistors(OFETs) based on poly(3-hexylthiophene)(P3HT) with different concentrations in chloroform(CHCl3) are fabricated.The output characteristics indicate that the P3HT concentrati...Top-contact organic field effect transistors(OFETs) based on poly(3-hexylthiophene)(P3HT) with different concentrations in chloroform(CHCl3) are fabricated.The output characteristics indicate that the P3HT concentration has significant influence on the OFET devices.The performance of the devices firstly is enhanced with increasing the P3HT concentration,and then decreases.The optimized devices with the P3HT concentration of 2 mg/mL show the best performance.The fieldeffect mobility is up to 1.4×10-2 cm2/Vs,the threshold voltage(Vt) is as low as-20 V,and the current on/off ratio(Ion/off) is close to the order of 104.The results suggest that the P3HT aggregation patterns induced by different concentrations can improve the performance of the OFETs.展开更多
In this paper,the pentacene-based organic field-effect transistors(OFETs)with poly(methyl methacrylate)(PMMA)as gate dielectrics were fabricated,and the effects of gate dielectric thickness and semiconductor thickness...In this paper,the pentacene-based organic field-effect transistors(OFETs)with poly(methyl methacrylate)(PMMA)as gate dielectrics were fabricated,and the effects of gate dielectric thickness and semiconductor thickness on the device performance were investigated.The optimal PMMA thickness is in the range of 350–400 nm to sustain a considerable current density and stable performance.The device performance depends on the thicknesses of the active layer non-monotonically,which can be explained by the morphology of the pentacene film and the position of the conducting channel in the active layer.The device with a pentacene thickness of 50 nm shows the best performance,which has a maximum hole mobility of 1.12 cm2/V·s.In addition,the introduction of a thin layer of tris-(8-hydroxyquinolinato)aluminum(Alq3)to the OFETs as a light-emitting material greatly decreases the device performance.展开更多
文摘The aim of the work was the study of the effect of NEMP (nanosecond electromagnetic pulses) on steel properties. Steel treatment was performed under the workshop conditions. The mechanical properties and the microstructure of the experimental samples and samples prepared by usual way were analyzed. The treatment of metal melt with nanosecond electromagnetic pulses at the crystallization stage makes it possible to change mechanical properties of metal and its structure.
基金partially supported by the National Natural Science Foundation of China(9133310121133007+1 种基金21573175)the support from Scientific Research Foundation of Henan University(B2013141)
文摘It has been experimentally demonstrated that the stereometric packings of two new bisPC_(71) BM isomers have an important impact on the power conversion efficiency of organic solar cells. Here, a theoretical investigation is made to reveal the mechanism behind from detailed photophysical processes in performed cells. The results show that the crystal packings of isomers affect the electron mobilities dominantly from the electronic coupling for electron transfer, and the trends of calculated mobilities are consistent with experimental measurements although the magnitudes are obviously larger. For the performed cells from two isomers with poly(3-hexylthiophene) as a donor, it is found that the exciton dissociation yields are also different, manifesting that stereometric packings essentially control the cell efficiency via both electron mobilities and exciton dissociation. Furthermore,the reasons for low cell efficiencies are analyzed, and possible improvements are suggested.
基金financially supported by the National Basic Research Program of China(2013CB933501)the National Natural Science Foundation of Chinasupported by a General Financial Grant(2013M530135)from the China Postdoctoral Science Foundation
文摘Organic electron acceptor materials play an important role in organic electronics.Recently,many organic electron acceptors have been developed,in which aromatic fused-imides have proved to be a promising family of excellent electron acceptors.We report the first synthesis of a novel aromatic fused-imide,acenaphtho[1,2-k]fluoranthene diimide derivative(AFI),using lithium-halogen exchange and Diels-Alder reactions.The construction of a large conjugated plane and the introduction of electron-withdrawing imide groups endow AFI with a low lowest unoccupied molecular orbital(LUMO)level of 3.80 e V.AFI exhibits a regular molecular arrangement and strong - interactions in the single-crystal structure,which indicates its potential application in organic electronic devices.Solar cell devices that were fabricated using AFI as the electron acceptor and P3HT as the electron donor achieved an energy conversion efficiency of 0.33%.
基金supported by the National Natural Science Foundation of China (No.60676051)the Natural Science Fund of Tianjin (No.07JCYBJC12700)the Fund of Key Discipline of Material Physics and Chemistry of Tianjin
文摘Top-contact organic field effect transistors(OFETs) based on poly(3-hexylthiophene)(P3HT) with different concentrations in chloroform(CHCl3) are fabricated.The output characteristics indicate that the P3HT concentration has significant influence on the OFET devices.The performance of the devices firstly is enhanced with increasing the P3HT concentration,and then decreases.The optimized devices with the P3HT concentration of 2 mg/mL show the best performance.The fieldeffect mobility is up to 1.4×10-2 cm2/Vs,the threshold voltage(Vt) is as low as-20 V,and the current on/off ratio(Ion/off) is close to the order of 104.The results suggest that the P3HT aggregation patterns induced by different concentrations can improve the performance of the OFETs.
基金supported by the National Natural Science Foundation of China(Grant Nos.61177017,61275175,61036007,61377028,and 61077022)National Science Foundation for Distinguished Young Scholars of China(Grant No.61125505)the"111" Project of China(Grant No.B08002)
文摘In this paper,the pentacene-based organic field-effect transistors(OFETs)with poly(methyl methacrylate)(PMMA)as gate dielectrics were fabricated,and the effects of gate dielectric thickness and semiconductor thickness on the device performance were investigated.The optimal PMMA thickness is in the range of 350–400 nm to sustain a considerable current density and stable performance.The device performance depends on the thicknesses of the active layer non-monotonically,which can be explained by the morphology of the pentacene film and the position of the conducting channel in the active layer.The device with a pentacene thickness of 50 nm shows the best performance,which has a maximum hole mobility of 1.12 cm2/V·s.In addition,the introduction of a thin layer of tris-(8-hydroxyquinolinato)aluminum(Alq3)to the OFETs as a light-emitting material greatly decreases the device performance.