In this paper a simple method for determination of the apparent mobility of cation in a soil colloid system was described. With this method apparent mobilities of Na+, K+, and Ca2+ ions in the systems of the ferric lu...In this paper a simple method for determination of the apparent mobility of cation in a soil colloid system was described. With this method apparent mobilities of Na+, K+, and Ca2+ ions in the systems of the ferric luvisol, acrisol, and ferralsol were determined, and the reduction percentages of the mobilities were calculated. The results showed that the apparent mobilities of different cations at the same normality in a given soil system were in the order UNa> UK> UCa; those of the same cations among different soil systems were in the order ferralsol > acrisol > ferric luvisol, but the reduction percentages were in a reverse order, which among different cations at the same normality was Ca2+> K+> Na+ for ferric luvisol and acrisol systems, but was K+> Ca2+> Na+ for farralsol system. These results were interpreted in terms of different amounts of negative charge the clay fraction of different soils carries, and different mechanisms by which the soils adsorb the cations.展开更多
The deep-level traps at grain boundaries(GBs)and halide ion migration are quite challenging for further enhancement of the stability and efficiency of perovskite solar cells(PSCs)as well as for the elimination of noto...The deep-level traps at grain boundaries(GBs)and halide ion migration are quite challenging for further enhancement of the stability and efficiency of perovskite solar cells(PSCs)as well as for the elimination of notorious hysteresis.Herein,we report a large-sized strongly coordinated organic anion GB anchoring strategy for suppressing ion migration and passivating defects in planar PSCs.The practical implementation of this strategy involves the incorporation of potassium salts containing a large-sized organic counter anion(4-sulfobenzoic acid monopotassium salt,SAMS)into the perovskite precursor.It has been found that anions within SAMS can be firmly anchored at GBs due to the strong coordination interaction between C=O and/or S=O at both ends of bulky anion and undercoordinated Pb^(2+)and/or halide vacancies,along with the hydrogen bond between–OH and formamidinium.SAMS can not only passivate shallowlevel defects but also cause more effective passivation of the deep-level defects.The GB manipulation strategy results in a reduced defect density,an increased carrier lifetime as well as suppressed ion migration,which in turn contributed to enhanced efficiency and stability of PSCs together with a thorough elimination of hysteresis.As a result,the SAMSmodified device with an outstanding fill factor of 0.84 delivers a significant improvement in efficiency(22.7%)in comparison with the control device(20.3%).The unencapsulated modified device demonstrates only little degradation after 1320 h at 60℃.展开更多
文摘In this paper a simple method for determination of the apparent mobility of cation in a soil colloid system was described. With this method apparent mobilities of Na+, K+, and Ca2+ ions in the systems of the ferric luvisol, acrisol, and ferralsol were determined, and the reduction percentages of the mobilities were calculated. The results showed that the apparent mobilities of different cations at the same normality in a given soil system were in the order UNa> UK> UCa; those of the same cations among different soil systems were in the order ferralsol > acrisol > ferric luvisol, but the reduction percentages were in a reverse order, which among different cations at the same normality was Ca2+> K+> Na+ for ferric luvisol and acrisol systems, but was K+> Ca2+> Na+ for farralsol system. These results were interpreted in terms of different amounts of negative charge the clay fraction of different soils carries, and different mechanisms by which the soils adsorb the cations.
基金the Support Plan for Overseas Students to Return to China for Entrepreneurship and Innovation(cx2020003)the Fundamental Research Funds for the Central Universities(2020CDJQY-A028 and 2020CDJ-LHZZ-074)the Natural Science Foundation of Chongqing(cstc2020jcyj-msxmX0629)。
文摘The deep-level traps at grain boundaries(GBs)and halide ion migration are quite challenging for further enhancement of the stability and efficiency of perovskite solar cells(PSCs)as well as for the elimination of notorious hysteresis.Herein,we report a large-sized strongly coordinated organic anion GB anchoring strategy for suppressing ion migration and passivating defects in planar PSCs.The practical implementation of this strategy involves the incorporation of potassium salts containing a large-sized organic counter anion(4-sulfobenzoic acid monopotassium salt,SAMS)into the perovskite precursor.It has been found that anions within SAMS can be firmly anchored at GBs due to the strong coordination interaction between C=O and/or S=O at both ends of bulky anion and undercoordinated Pb^(2+)and/or halide vacancies,along with the hydrogen bond between–OH and formamidinium.SAMS can not only passivate shallowlevel defects but also cause more effective passivation of the deep-level defects.The GB manipulation strategy results in a reduced defect density,an increased carrier lifetime as well as suppressed ion migration,which in turn contributed to enhanced efficiency and stability of PSCs together with a thorough elimination of hysteresis.As a result,the SAMSmodified device with an outstanding fill factor of 0.84 delivers a significant improvement in efficiency(22.7%)in comparison with the control device(20.3%).The unencapsulated modified device demonstrates only little degradation after 1320 h at 60℃.