Study On PCPDTBT:ICBA And Three Kinds Of Polymer Solar Cells With ICBA As Acceptor

Organic polymer solar cells has been a focus of international research, it has a light weight, low energy consumption, the preparation is relatively simple, can be made flexible solar cells, etc. However, the most studied classical system P3HT:PCBM system due to restrictions P3HT wide bandgap and PCBM lower LUMO level and other factors, the efficiency has been unable to break through. In the present study, the author introduces a low bandgap material PCPDTBT as donor material, the material bandgap narrow and spectral absorption width. While the introduction of ICBA as a receptor material (ICBA has0.17ev higher LUMO energy level than the PCBM) to seek greater efficiency. In this study, we use PCPDTBT:ICBA polymer solar cells as the basic research, make comparative study with P3HT:ICBA and PDPP3T:ICBA,found the root causes of why the efficiency of the PCPDTBT:ICBA system failed to meet the expectations. The specific content of the work can be divided into two parts.Firstly, basic research on PCPDTBT:ICBA System. The study found that Preparation PCPDTBT:ICBA system optimum conventional device thickness is70-80nm. PCPDTBT:ICBA system polymer solar cells inverted geometry device exhibit better photoelectric efficiency than the conventional devices, make optimal inverted geometry devices thickness is about60nm. Calculated the doping density of PCPDTBT:ICBA and P3HT:ICBA under the optimum conditions are separately2.25*1016cm-3and1.6*1016cm-3. The doping density could be changed through annealing or changing the solvent, changing the doping density will cause a change in open circuit voltage and short circuit current, the doping density increases, the open circuit voltage increases, the short-circuit current decreases, and vice versa.Secondly, a comparative study of three kinds of polymer solar cell with ICBA as acceptor Using P3HT、PCPDTBT、PDPP3T as a donor and a fullerene derivative ICBA as acceptor, three different polymer solar cells were prepared for comparative study. The results indicate that the performance are very different among the three groups of devices. The excition generation rate and the carrier motilities are not significantly different. The photoluminescence study indicates that the exciton separation efficiencies are apparently different, which is the main reason to cause the performance gap among the three devices...