苯乙胺钝化钙钛矿埋底界面提高太阳能电池性能  

Passivation of Perovskite Buried-interface Using Phenethylamine for Enhanced Solar Cell Performance

作　　者：张康杰 闫伟博[1] 辛颢[1] ZHANG Kangjie;YAN Weibo;XIN Hao(State Key Laboratory for Organic Electronics and Information Displays&Institute of Advanced Materials(IAM),Nanjing University of Posts&Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学有机电子与信息显示国家重点实验室&先进材料研究院,江苏南京210023

出　　处：《发光学报》2023年第9期1636-1643,共8页Chinese Journal of Luminescence

基　　金：国家自然科学基金(61704087);南京邮电大学自然科学基金(NY222131)。

摘　　要：采用有机小分子钝化钙钛矿下表面(埋底界面)可以有效抑制钙钛矿埋底界面缺陷形成,降低载流子复合几率。本工作通过预先沉积钝化分子苯乙胺(PEA)的方法来钝化钙钛矿埋底界面。钝化后的钙钛矿晶粒大小与表面形貌无明显变化,吸收边和发光波长稍有红移,最高分子占据轨道能级略有提高。“Pb”元素结合能向高能级移动,而“N”元素结合能向低能级移动,并且钙钛矿中PbI2的残留量明显减少,表明钝化分子PEA通过“N”原子与钙钛矿下表面悬挂的“Pb”以及残留PbI2相互作用。基于PEA钝化的钙钛矿电池的开路电压、短路电流密度、填充因子和转换效率分别从1.041 V、21.29 mA/cm2、74.09%和16.41%提高到1.102 V、22.44 mA/cm2、79.28%和19.6%。器件性能的显著提高主要由于载流子的复合降低,归因于:(1)PEA钝化未饱和配位“Pb”引起的缺陷;(2)PEA钝化卤化铅微晶组成的复杂相引起的缺陷;(3)钙钛矿与空穴传输层之间的电荷转移速率的提高。钝化的钙钛矿电池器件稳定性明显增强。这种简便、有效的埋底界面钝化策略可以应用于未来大面积钙钛矿太阳能电池的制备。Passivation of the lower surface(buried interface)of perovskite using organic small molecules is an effective strategy to suppress carrier recombination.This work focuses on passivation of the buried interface of perovskite by pre-coating the passivation material of phenylethylamine(PEA)before depositing the perovskite film.After passivation treatment,the grain size and morphology of the perovskite crystalline film did not change.After passivation,there is a slight red-shift in the absorption edge and emission wavelength of perovskite,and a slight increase in the energy level of highest occupied molecular orbital.“Pb”binding energy moves to a higher level,while“N”binding energy moves to a lower level.These results confirm that the“N”atoms on PEA molecules can interact with the dangling“Pb”at the buried interface of perovskite.The results showed a significant reduction of residual PbI2 in perovskite,indicating that PEA molecules reacted with PbI2 to form a certain complex.Furthermore,the solar cells were fabricated to investigate the passivation effect and the results showed that the open-circuit voltage(Voc),short-circuit current density(Jsc),fill factor(FF)and power conversion Efficiency(PCE)of the control perovskite solar cells were 1.041 V,21.29 mA/cm^(2),74.09%,and 16.41%,which for PEA-passivated perovskite solar cells,increased to 1.102 V,22.44 mA/cm^(2),79.28%,and 19.6%,respectively.The significant improvement of device performance induced by passivation of perovskite buried-interface defects is mainly due to the reduction of carrier recombination which mainly attributed to passivation of the defects caused by unsaturated-coordination“Pb”,passivation of the defects caused by the complex phases of PbI2 microcrystals,and improvement of the charge transfer rate between perovskite and the hole-transporting layer.The stability of passivated perovskite solar cells is significantly enhanced.This simple and effective buried-interface passivation strategy can be applied to the fabrication of larg

关 键 词：能量传递钙钛矿 埋底界面 苯乙胺 钝化 太阳能电池 

分 类 号：O482.31[理学—固体物理] TM914.4[理学—物理]