Dipolar cations confer defect tolerance in wide-bandgap metal halide perovskites.
Dipolar cations confer defect tolerance in wide-bandgap metal halide perovskites.
复制标题
DOI：
10.1038/s41467-018-05531-8
复制
发表时间：
2018-08-06
影响因子：
16.6
通讯作者：
Sargent EH
中科院分区：
文献类型：
--
作者：
Tan H;Che F;Wei M;Zhao Y;Saidaminov MI;Todorović P;Broberg D;Walters G;Tan F;Zhuang T;Sun B;Liang Z;Yuan H;Fron E;Kim J;Yang Z;Voznyy O;Asta M;Sargent EH
高效宽禁带钙钛矿太阳能电池(PSCs)与晶硅和其他低禁带吸收材料相结合，可实现高效串联光伏发电。然而，目前宽带隙PSC的性能远不如1.6 eV以下的带隙PSC，这是因为它们倾向于形成高密度的深陷阱。在这里，我们展示了修复宽禁带钙钛矿中的深陷阱--实际上，通过阳离子工程增加缺陷容忍度--能够进一步提高PSC的性能。对于1.65 eV带隙PSC，我们通过引入偶极阳离子获得了20.7%的稳定功率转换效率，高开路电压为1.22 V，填充因子超过80%。在1.25 V的高开路电压下，我们还获得了19.1%的稳定效率。从密度泛函理论计算中，我们发现在混合的阳离子-卤化物钙钛矿中偶极阳离子的存在和重新取向修复了引入深陷陷态的缺陷。宽禁带钙钛矿型光伏电池的性能受到不必要的相变和高密度的深能级陷阱的限制。在这里，Tan等人。加入偶极甲基铵阳离子，使材料具有容错性，实现了20.7%的高功率转换效率。
Efficient wide-bandgap perovskite solar cells (PSCs) enable high-efficiency tandem photovoltaics when combined with crystalline silicon and other low-bandgap absorbers. However, wide-bandgap PSCs today exhibit performance far inferior to that of sub-1.6-eV bandgap PSCs due to their tendency to form a high density of deep traps. Here, we show that healing the deep traps in wide-bandgap perovskites—in effect, increasing the defect tolerance via cation engineering—enables further performance improvements in PSCs. We achieve a stabilized power conversion efficiency of 20.7% for 1.65-eV bandgap PSCs by incorporating dipolar cations, with a high open-circuit voltage of 1.22 V and a fill factor exceeding 80%. We also obtain a stabilized efficiency of 19.1% for 1.74-eV bandgap PSCs with a high open-circuit voltage of 1.25 V. From density functional theory calculations, we find that the presence and reorientation of the dipolar cation in mixed cation–halide perovskites heals the defects that introduce deep trap states. The performance of wide-bandgap perovskite photovoltaics is limited by the undesired phase transition and high density of deep level traps. Here, Tan et al. incorporate dipolar methylammonium cation to make the material defect-tolerant and achieve a high power conversion efficiency of 20.7%.
登录
查看更多内容
影响因子：
3.8
作者：
Jaeger, Klaus;Korte, Lars;Albrecht, Steve
通讯作者：
Albrecht, Steve
影响因子：
10.8
作者：
Frost JM;Butler KT;Brivio F;Hendon CH;van Schilfgaarde M;Walsh A
通讯作者：
Walsh A
影响因子：
16.6
作者：
Chen Y;Yi HT;Wu X;Haroldson R;Gartstein YN;Rodionov YI;Tikhonov KS;Zakhidov A;Zhu XY;Podzorov V
通讯作者：
Podzorov V
影响因子：
56.7
作者：
Bush, Kevin A.;Palmstrom, Axel F.;McGehee, Michael D.
通讯作者：
McGehee, Michael D.
影响因子：
64.8
作者：
Jeon, Nam Joong;Noh, Jun Hong;Seok, Sang Il
通讯作者：
Seok, Sang Il