Integrating Ultrathin Bulk-Heterojunction Organic Semiconductor Intermediary for High-Performance Low-Bandgap Perovskite Solar Cells with Low Energy Loss
Integrating Ultrathin Bulk-Heterojunction Organic Semiconductor Intermediary for High-Performance Low-Bandgap Perovskite Solar Cells with Low Energy Loss
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DOI：
10.1002/adfm.201804427
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发表时间：
2018-10-17
影响因子：
19
通讯作者：
Li, Yongfang
中科院分区：
文献类型：
--
作者：
Xu, Guiying;Bi, Pengqing;Li, Yongfang
混合锡铅钙钛矿被认为是最有前途的低带隙光伏材料，既追求单结太阳能电池的理论极限效率，又通过构建串联太阳能电池来打破Shockley-Queisser限制。然而，由于其严重的能量损失（E-loss），它们的功率转换效率（PCE）仍然落后于中带隙钙钛矿太阳能电池（pero-SC）。在此，将半导体本体异质结（BHJ）有机半导体（PBDB-T：ITIC）层用作空穴传输层和Sn-Pb基低带隙钙钛矿膜之间的中间体以使E损失最小化。结果发现，这种BHJ PBDB-T：ITIC中间体同时提供了一个级联的能量对齐的设备，促进高品质的锡铅钙钛矿薄膜的生长，并钝化钙钛矿表面的反位缺陷。以这种简单的方式，基于（FASnI（3））（0.6）（MAPbI（3））（0.4）（带隙接近1.25 eV）的pero-SC的E损耗显著降低到0.4 eV以下，导致0.86 V的高开路电压（V-oc）。结果，最佳的pero-SC显示出18.03%的显著改善的PCE，具有可忽略的J-V滞后和高稳定性。据了解，18.03%的PCE和0.86 V的V-oc是迄今为止低带隙pero-SC中的最高值。
Mixed tin (Sn)-lead (Pb) perovskite is considered the most promising low-bandgap photovoltaic material for both pursuing the theoretical limiting efficiency of single-junction solar cells and breaking the Shockley-Queisser limitation by constructing tandem solar cells. However, their power conversion efficiencies (PCEs) are still lagging behind those of medium-bandgap perovskite solar cells (pero-SCs) due to their serious energy loss (E-loss). Here, an ultrathin bulk-heterojunction (BHJ) organic semiconductor (PBDB-T:ITIC) layer is used as an intermediary between the hole transporting layer and Sn-Pb-based low-bandgap perovskite film to minimize E-loss. It is found that this BHJ PBDB-T:ITIC intermediary simultaneously provided a cascading energy alignment in the device, facilitated high-quality Sn-Pb perovskite film growth, and passivated the antisite defects of the perovskite surface. In this simple way, the E-loss of pero-SCs based on (FASnI(3))(0.6)(MAPbI(3))(0.4) (bandgap approximate to 1.25 eV) is dramatically reduced below 0.4 eV, leading to a high open-circuit voltage (V-oc) of 0.86 V. As a result, the best pero-SC showed a significantly improved PCE of 18.03% with negligible J-V hysteresis and high stability. As far as it is known, the PCE of 18.03% and V-oc of 0.86 V are the highest values among the low-bandgap pero-SCs to date.