研究了面状分布缺陷开口谐振环(split ring resonators,SRRs)组对三维左手材料的微波透射行为的影响.用电路板刻蚀技术制备了以六边形SRRs与金属铜Wires组合为结构单元的三维左手材料样品,利用波导法测量了含有不同空间取向面缺陷SRRs...研究了面状分布缺陷开口谐振环(split ring resonators,SRRs)组对三维左手材料的微波透射行为的影响.用电路板刻蚀技术制备了以六边形SRRs与金属铜Wires组合为结构单元的三维左手材料样品,利用波导法测量了含有不同空间取向面缺陷SRRs构成的三维左手材料X波段(8-12GHz)微波透射行为.实验表明,相对于无缺陷情形,面缺陷的引入使谐振峰谐振频率移动,且红移、蓝移的情况都存在;谐振强度明显下降,最多达到19.3 dB,相当于原来的46%;通频带宽在[315-817.5 MHz]范围变化.面缺陷的存在破坏了材料的周期性结构,导致形成新的电磁谐振条件、谐振峰发生变化.不同空间取向的面缺陷对材料周期性结构改变程度不同,其缺陷效应差异较大.相对于点缺陷、线缺陷,面缺陷效应更强.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
文摘研究了面状分布缺陷开口谐振环(split ring resonators,SRRs)组对三维左手材料的微波透射行为的影响.用电路板刻蚀技术制备了以六边形SRRs与金属铜Wires组合为结构单元的三维左手材料样品,利用波导法测量了含有不同空间取向面缺陷SRRs构成的三维左手材料X波段(8-12GHz)微波透射行为.实验表明,相对于无缺陷情形,面缺陷的引入使谐振峰谐振频率移动,且红移、蓝移的情况都存在;谐振强度明显下降,最多达到19.3 dB,相当于原来的46%;通频带宽在[315-817.5 MHz]范围变化.面缺陷的存在破坏了材料的周期性结构,导致形成新的电磁谐振条件、谐振峰发生变化.不同空间取向的面缺陷对材料周期性结构改变程度不同,其缺陷效应差异较大.相对于点缺陷、线缺陷,面缺陷效应更强.
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℃.
