The Studies Of Interfacial Self-organization And Photo-stability Of Organic Solar Cells

The rapid development of organic solar cells in the past few years has been aided by the development of new non-fullerene-receptor materials.Currently,the most efficient devices have exceeded 16%,which plies the way for the application of organic solar energy in the future.However,to realize the real commercialization,it is necessary to solve the technical problem of large-scale processing and the problem of light stability.Therefore,the two main works of this paper are developed around these two problems respectively.Firstly,in order to simplify the processing procedure of traditional inverted device structure,we added the n-type polymer PF3N-2TNDI as the cathode interface material in the active layer solution,and directly coated the mixed solution of indium tin oxide?ITO?on the electrode substrate.The device performance prepared can be compared with the device using zinc oxide as the electron transport layer.Based on PTB7-th:PC₇₁BM system,the optimal efficiency of devices prepared by this strategy can reach 8.83%.Our materials,and through the interface to the surface of the receptor can test,found that the interface material surface can be greater than for donor and acceptor,suggesting that interface material and the effect of ITO is better than to donor and acceptor and the role of ITO,therefore in the process of spin coating interface material will be formed a layer of ITO side electron transport layer,so as to simplify the process of target.Through the XPS test,also verified our speculation.This work can simplify the processing process and avoid some interfaces that cannot be made thick and difficult to be applied in a large area,providing some solutions for future OPV roll to roll processing.Then,in order to solve the current problem of poor illumination stability of organic solar cells in the non-fullerene system,we expected to improve the illumination stability of the whole device by improving the illumination stability of the active layer film morphology.Firstly,a layer of C₆₀-SAM is formed on the interface of zinc oxide to modify zinc oxide.On the one hand,surface defects of zinc oxide can be passivated.On the other hand,the surface energy of the substrate in contact with the active layer can be changed to regulate the morphology of the active layer.Through the light stability test can be found after modification,the device was improved light stability is obvious and through GIWAXS test could be seen in C₆₀-SAM substrate deposition of thin film crystallization is weaker than zinc oxide substrate,at the same time,it is more close to the membrane of the crystallization of the weaker after aging,so as to achieve a stable performance of active layer morphology and purpose.To this end,we consider the attenuation of the crystallization can further enhance the light stability of the device,our testing found that green solvent o-xylene processing of the crystallization of the thin film of weak in chlorobenzene,so we will o-xylene solvent processing and C₆₀-SAM interface modification could be prepared for the combination of thin film crystallization is the weakest in several processing conditions,under the light stability test,we can see the light stability of the device greatly enhance,through the device 2000 hours test curve fitting,T80 values can be obtained for 33930 h.Through this work,we know that solvent selection and interface modification can improve the optical stability of devices by affecting the morphology of organic films,which not only provides a new idea for us to improve the optical stability of devices,but also lays a foundation for the industrialization of OPV in the future.