Asandulesa Mihai, Kostromin Sergei, Aleksandrov Alexey, Tameev Alexey, Bronnikov Sergei
Romanian Academy, Petru Poni Institute of Macromolecular Chemistry, Iaşi 700487, Romania.
Russian Academy of Sciences, Institute of Macromolecular Compounds, St. Petersburg 199004, Russian Federation.
Phys Chem Chem Phys. 2022 Apr 20;24(16):9589-9596. doi: 10.1039/d2cp00770c.
A ternary photovoltaic blend containing the PTB7 donor component, the PC71BM acceptor component, and colloidal quantum dots of lead sulfide (PbS QDs) was investigated using broadband dielectric spectroscopy. In the dielectric loss spectrum of PTB7:PC71BM:PbS QDs, γ- and β-relaxation processes in PTB7 were recognized and analyzed in terms of Arrhenius-type equations. To elucidate the effect of PbS QDs on molecular dynamics of PTB7, the activation energies of both processes were evaluated and compared with those obtained for the binary PTB7:PC71BM blend. Using the CELIV method, the charge carrier mobility was estimated. The PbS QD incorporation into the binary blend was shown to decrease both electron and hole mobility in the ternary PTB7:PC71BM:PbS QD blend. For evaluating the charge carrier lifetime in the ternary blend, the Cole-Cole diagrams derived from the dc conductivity data were plotted. The charge carrier lifetime was found to be much less than the hole extraction time, thus providing effective accumulation of charge carries at the electrodes in the ternary blend under investigation.
使用宽带介电谱研究了一种包含PTB7供体组分、PC71BM受体组分和硫化铅胶体量子点（PbS量子点）的三元光伏共混物。在PTB7:PC71BM:PbS量子点的介电损耗谱中，识别出了PTB7中的γ-和β-弛豫过程，并根据阿伦尼乌斯型方程进行了分析。为了阐明PbS量子点对PTB7分子动力学的影响，评估了这两个过程的活化能，并与二元PTB7:PC71BM共混物获得的活化能进行了比较。使用CELIV方法估计了电荷载流子迁移率。结果表明，在三元PTB7:PC71BM:PbS量子点共混物中加入PbS量子点会降低电子和空穴迁移率。为了评估三元共混物中的电荷载流子寿命，绘制了由直流电导率数据得出的科尔-科尔图。发现电荷载流子寿命远小于空穴提取时间，从而在所研究的三元共混物中在电极处实现了电荷载流子的有效积累。
