Kim Seul-Gi, Le Thi Huong, de Monfreid Thybault, Goubard Fabrice, Bui Thanh-Tuân, Park Nam-Gyu
School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon, 440-746, Korea.
CY Cergy Paris Université, LPPI, Cergy, F-95000, France.
Adv Mater. 2021 Mar;33(12):e2007431. doi: 10.1002/adma.202007431. Epub 2021 Feb 19.
A thermally stable perovskite solar cell (PSC) based on a new molecular hole transporter (MHT) of 1,3-bis(5-(4-(bis(4-methoxyphenyl) amino)phenyl)thieno[3,2-b]thiophen-2-yl)-5-octyl-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (coded HL38) is reported. Hole mobility of 1.36 × 10 cm V s and glass transition temperature of 92.2 °C are determined for the HL38 doped with lithium bis(trifluoromethanesulfonyl)imide and 4-tert-butylpyridine as additives. Interface engineering with 2-(2-aminoethyl)thiophene hydroiodide (2-TEAI) between the perovskite and the HL38 improves the power conversion efficiency (PCE) from 19.60% (untreated) to 21.98%, and this champion PCE is even higher than that of the additive-containing 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeOTAD)-based device (21.15%). Thermal stability testing at 85 °C for over 1000 h shows that the HL38-based PSC retains 85.9% of the initial PCE, while the spiro-MeOTAD-based PSC degrades unrecoverably from 21.1% to 5.8%. Time-of-flight secondary-ion mass spectrometry studies combined with Fourier transform infrared spectroscopy reveal that HL38 shows lower lithium ion diffusivity than spiro-MeOTAD due to a strong complexation of the Li with HL38, which is responsible for the higher degree of thermal stability. This work delivers an important message that capturing mobile Li in a hole-transporting layer is critical in designing novel MHTs for improving the thermal stability of PSCs. In addition, it also highlights the impact of interface design on non-conventional MHTs.
报道了一种基于新型分子空穴传输体（MHT）1,3-双（5-（4-（双（4-甲氧基苯基）氨基）苯基）噻吩并[3,2-b]噻吩-2-基）-5-辛基-4H-噻吩并[3,4-c]吡咯-4,6（5H）-二酮（编码为HL38）的热稳定钙钛矿太阳能电池（PSC）。对于掺杂双（三氟甲磺酰）亚胺锂和4-叔丁基吡啶作为添加剂的HL38，测定其空穴迁移率为1.36×10⁻³ cm² V⁻¹ s⁻¹，玻璃化转变温度为92.2℃。在钙钛矿和HL38之间用2-（2-氨基乙基）噻吩氢碘化物（2-TEAI）进行界面工程，将功率转换效率（PCE）从19.60%（未处理）提高到21.98%，并且这个最佳PCE甚至高于含添加剂的基于2,2',7,7'-四（N,N-二对甲氧基苯胺）-9,9'-螺二芴（spiro-MeOTAD）的器件（21.15%）。在85℃下进行超过1000小时的热稳定性测试表明，基于HL38的PSC保留了初始PCE的85.9%，而基于spiro-MeOTAD的PSC从2l.1%不可恢复地降解到5.8%。飞行时间二次离子质谱研究与傅里叶变换红外光谱相结合表明，由于Li与HL38的强络合作用，HL38显示出比spiro-MeOTAD更低的锂离子扩散率，这导致了更高程度的热稳定性。这项工作传递了一个重要信息，即在空穴传输层中捕获移动的Li对于设计用于提高PSC热稳定性的新型MHT至关重要。此外，它还突出了界面设计对非常规MHT的影响。
