Kulshreshtha Chandramouli, Clement Arul, Pascher Torbjörn, Sundström Villy, Matyba Piotr
Department of Physics, Umeå University Umeå 90187 Sweden
Swanson School of Engineering, University of Pittsburgh 3700 O'Hara Street Pittsburgh PA 15261 USA.
RSC Adv. 2020 Feb 12;10(11):6618-6624. doi: 10.1039/c9ra10009a. eCollection 2020 Feb 7.
Here, we show a new diketopyrrole based polymeric hole-transport material (PBDTP-DTDPP, (poly[[2,5-bis(2-hexyldecyl)-2,3,5,6-tetrahydro-3,6-dioxopyrrolo[3,4-]pyrrole-1,4-diyl]--[[2,2'-(4,8-bis(4-ethylhexyl-1-phenyl)-benzo[1,2-:4,5-']dithiophene)bis-thieno[3,2-]thiophen]-5,5'-diyl]])) for application in perovskite solar cells. The material performance was tested in a solar cell with an optimized configuration, FTO/SnO/perovskite/PBDTP-DTDPP/Au, and the device showed a power conversion efficiency of 14.78%. The device charge carrier dynamics were investigated using transient absorption spectroscopy. The charge separation and recombination kinetics were determined in a device with PBDTP-DTDPP and the obtained results were compared to a reference device. We find that PBDTP-DTDPP enables similar charge separation time (<∼4.8 ps) to the spiro-OMeTAD but the amount of nongeminate recombination is different. Specifically, we find that the polymeric PBDTP-DTDPP hole-transport layer (HTL) slows-down the second-order recombination much less than spiro-OMeTAD. This effect is of particular importance in studying the charge transportation in optimized solar cell devices with diketopyrrole based HTL materials.
在此，我们展示了一种新型的基于二酮吡咯的聚合物空穴传输材料（PBDTP-DTDPP，聚[[2,5-双(2-己基癸基)-2,3,5,6-四氢-3,6-二氧代吡咯并[3,4-c]吡咯-1,4-二基]-[[2,2'-(4,8-双(4-乙基己基)-1-苯基)-苯并[1,2-b:4,5-b']二噻吩]并噻吩并[3,2-b]噻吩]-5,5'-二基]]），用于钙钛矿太阳能电池。在具有优化结构FTO/SnO/钙钛矿/PBDTP-DTDPP/Au的太阳能电池中测试了该材料的性能，该器件的功率转换效率为14.78%。使用瞬态吸收光谱研究了器件的电荷载流子动力学。在具有PBDTP-DTDPP的器件中确定了电荷分离和复合动力学，并将所得结果与参考器件进行了比较。我们发现，PBDTP-DTDPP能够实现与螺环-OMeTAD相似的电荷分离时间（<约4.8皮秒），但非成对复合的量不同。具体而言，我们发现聚合物PBDTP-DTDPP空穴传输层（HTL）对二阶复合的减缓作用远小于螺环-OMeTAD。这种效应在研究具有基于二酮吡咯的HTL材料的优化太阳能电池器件中的电荷传输时尤为重要。
