Excitation Intensity Dependent Carrier Dynamics of Chalcogen Heteroatoms in Medium-Bandgap Polymer Solar Cells.
Excitation Intensity Dependent Carrier Dynamics of Chalcogen Heteroatoms in Medium-Bandgap Polymer Solar Cells.
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DOI：
10.1038/s41598-017-00834-0
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发表时间：
2017-04-11
影响因子：
4.6
通讯作者：
Cho K
中科院分区：
文献类型：
--
作者：
Kulshreshtha C;Son J;Pascher T;Kim JH;Joo T;Lee J;Jeong MS;Cho K
研究了三种具有中心硫属杂原子的新型中带隙共轭聚合物PBDTfDTBX（X = O、T（硫）、Se）与PC[70]BM共混物的激发强度依赖性载流子动力学。 PBDTfDTBX聚合物(聚[4,8-双(5-(2-丁基辛基)噻吩-2-基)苯并[1,2-b;4,5-b']二噻吩-alt-4,7-双(4-(2-乙基己基)-2-噻吩基)-二噻吩[3',2':3,4;2”,3”:5,6]苯并[1,2-c][1,2,5]呋喃嗪或噻二唑或硒二唑]）具有对称结构，但表现出不同的太阳能电池性能。在本研究中，我们通过在不同激发强度下进行瞬态吸收测量，确定了 PBDTfDTBX:PC[70]BM 混合物的光生电荷载流子动力学如何随杂原子变化。研究发现，具有 X = T 或 Se 杂原子的 PBDTfDTBX 共混物的载流子动力学取决于激发强度，而 PBDTfDTBO 共混物的载流子动力学与强度无关。 PBDTfDTBO:PCBM、PBDTfDTBT:PCBM 和 PBDTfDTBSe:PCBM 混合物的光生载流子动力学均进行了全局建模，并估计了不同时间尺度上发生的不同光物理过程的速率。
The excitation intensity dependent carrier dynamics of blends with PC[70]BM of three new medium-band gap conjugated polymers with central chalcogen heteroatoms, PBDTfDTBX (X = O, T(Sulphur), Se) were studied. The PBDTfDTBX polymers (Poly[4,8-bis(5-(2-butyloctyl)thiophene-2-yl)benzo[1,2-b;4,5-b′]dithiophene-alt-4,7-bis(4-(2-ethylhexyl)-2-thienyl)-dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2-c][1,2,5] furazan or thiadiazole or selenadiazole]) have symmetrical structures but exhibit different solar cell performances. In this study, we determined how the photogenerated charge carrrier dynamics of the PBDTfDTBX:PC[70]BM blends varies with the heteroatom by performing transient absorption measurements at various excitation intensities. It was found that the charge carrier dynamics of the PBDTfDTBX blends with X = T or Se heteroatoms are dependent on the excitation intensity whereas that of the PBDTfDTBO blend is independent of the intensity. The photogenerated charge carrier dynamics of the PBDTfDTBO:PCBM, PBDTfDTBT:PCBM, and PBDTfDTBSe:PCBM blends were all modeled globally and rates were estimated for different photophysical processes occurring on different time scales.