白光及紫外光辐照下甲氨碘化铅基钙钛矿太阳能电池降解机制差异  

Different Degradation Mechanism of CH_(3)NH_(3)PbI_(3) Based Perovskite Solar Cells under Ultraviolet and Visible Light Illumination

作　　者：卢岳[1,2] 葛杨 隋曼龄[1,2] Yue Lu;Yang Ge;Manling Sui(Institute of Microstructure and Properties of Advanced Materials,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124;Beijing Key Laboratory of Microstructure and Properties of Solids,Beijing University of Technology,Beijing 100124)

机构地区：[1]北京工业大学材料与制造学部固体微结构与性能研究所,北京100124 [2]北京工业大学固体微结构与性能北京市重点实验室,北京100124

出　　处：《化学学报》2021年第3期344-352,共9页Acta Chimica Sinica

基　　金：国家重点研究发展计划(No.2016YFB0700700);国家自然科学基金(Nos.11704015,51621003,12074016);北京市教委科研一般项目(No.KM202110005003);北京市教师队伍建设创新团队项目(No.IDHT20190503)资助.

摘　　要：本工作实验对比了可见光以及紫外光辐照下甲氨碘化铅(CH_(3)NH_(3)PbI_(3)即MAPbI_(3))基钙钛矿太阳能电池器件性能及微结构演变特征差异.结果表明可见光辐照下钙钛矿太阳能电池器件中MAPbI_(3)层发生降解的同时,伴随着Au元素从金属电极一侧向MAPbI_(3)和电子传输层SnO_(2)的界面处迁移现象.但相较于紫外光,可见光辐照下器件中Au元素的迁移速率慢30倍左右.这是由于器件电子传输层SnO_(2)具有较低的价带顶位置(-8.4 eV),它吸收紫外光激发出强氧化性的空穴h^(+),氧化碘离子I-生成I原子.而I原子会对金属电极层产生较大的破坏作用,促进Au^(+)离子的形成.因此可见光辐照下,尽管器件开路电压Voc一直保持较高的数值,但是Au元素的迁移以及钙钛矿层的分解,会引起短路电流密度Jsc的快速降低.本文为钙钛矿太阳能电池光照不稳定性的机理解释,提供了全新的理论依据.In recent years,the photoelectronic conversion efficiency(PCE)of organic-inorganic halide perovskite solar cell(PSC)devices has been improved greatly.However,these devices are not very stable,and it is hard to avoid the effect of visible or ultraviolet(UV)light on the performance decay of the organic-inorganic halide perovskite devices,and there is rare report on the evolution process of the microstructure of PSCs under the light illumination,let along discussing on the differ-ent degradation mechanism of PSCs between the UV and visible light soaking.To address these scientific issues,in this study,we compared the performance evolution of CH3NH3PbI3(MAPbI3)based PSCs during the UV and visible light irradi-ation.The experimental results show that the perovskite layer has been photodegraded from MAPbI3 into an amorphous phase under the white light LED soaking.Meanwhile,the migration of Au element from the electrode into the interface between MAPbI3 and SnO_(2)layers can also be captured.As comparing the kinetics of redox reaction of Au,we found that the for-mation rate of Au nanoparticle mass in PSCs under UV light irradiation is almost 30 times higher than that under visible light illumination.Considering on the different characteristics of microstructure evolution in PSCs under the UV and visible light irradiation,and theoretically analyzing the energy level of each functional layers in the device,the results confirm that UV light is easy to be adsorbed by electron transportation layer(ETL)of SnO_(2)to excite the electron-hole pairs,while the pho-to-excited holes have a low energy level of-8.4 eV,which could oxidize the iodide ions(I-)into atomic iodine(I atom).The I atoms would diffuse into the spiro-OMeTAD layer and metal electrode interface.Due to its strong oxidation property,the I atom would not only destroy the spiro-OMeTAD layer,but also oxidize the Au metal electrode into AuI,which acceler ated the generation of Au+.However,under the illumination of visible light,it is hard to excite the electron-hole pai

关 键 词：钙钛矿太阳能电池 光辐照 迁移动力学 电子显微学 光降解 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TB34[一般工业技术—材料科学与工程]