Application Of Perylene Bisimide Derivatives In Organic Solar Cells

In the past decades,the performance of organic solar cells has obtained significantly improvement.Energy conversion efficiency of single cells fabricated in laboratory increased from the initial <1% to 12%.Morphology of the active layer is an important factor to the performance of organic solar cells.Continuous micro-phase separation with suitable size can efficiently enhance the separation of exciton at the interface between donor and acceptor domain,which also help to increase the carrier mobility,lower the recombination loss caused by carrier accumulation.Interface engineering is another way to obtain high performance of OSCs,suitable interface can modify the work function of electrode,reduce the energy barrier between electrode and active layer to form ohmic contact.On the other side,it optimized the physical contact between them to lower the recombination loss caused by trap,and also raised the electronic extraction efficiency which help to obtain good performance of OSC.The research contents of this thesis are divided into active layer morphology and interface conductivity control:1.Used PTB7:PBI-C4 layer as the morphology inducing layer of active layer to fabricate high performance LBL ternary organic solar cells.PBI-C4 has a strong ability in self-aggregation which can form orderd π-π interaction even after blended with PTB7.The ideal morphology of the ternary active layer induced by it can increase the charge separation,transport and collection efficiency.The average PCE of LBL ternary organic solar cells fabricated in this method is 8.96%,which obtained 14% improvement when compared with traditional binary solar cells.This work demonstrates a new promising way to fabricate high performanced ternary OSCs by proper choose of the third sensitive component with aggregation ability.2.Developed the perylene bisimide system used as dopant in the photoconductive cathode interface.Perylene bisimide molecule with four-OH bond in Bay region(PBI-OH)functioned with ZnO which realized the homogeneous doping system of PBI-OH in ZnO to obtain photoconductive cathode interface.The conductivity of the film significantly increased under light,correspondingly promoted the electron mobility and enhanced the performance of organic solar cells.The PCE of devices based on this photoconductive cathode interface obtained 16% improvement(9.03% vs 7.78%).This work expanded the perylene bisimide system that can be used as dopant in photoconductive cathode interface,broaden the understanding of photoconductive cathode interface and provide novel ideals for structure design of perylene bisimide used in it.