Preparation And Optimization Of Organic Solar Cells

Organic polymer solar cell device is easy to manufacture,easy to manufacture molding,production cost is low,and for environmental green environmental non-toxic,in line with the requirements of green chemistry and a series of excellent features,as of now has become a hot spot in scientific research.At the same time,on the other hand,although the highest photoelectric conversion efficiency of organic photovoltaic devices has exceeded 10%,still can not meet the requirements of large-scale commercialization.Therefore,it is a series of effective means to improve the photovoltaic efficiency of the device by trying to synthesize the photovoltaic material with higher efficiency and to explore the new device structure and the device processing technology.The main contents of this paper are as follows:1.The development of non-fullerene acceptors(NFAs)is far behind the donors,thus it is very significant to design new NFAs matched with the mature donors to improve the performance of photovoltaic.A2-A1-D-A1-A2 type non-fullerene acceptor BTA9 comprised of electron-donating indacenodithienothiophene(IDT)and electron-accepting benzo[c][1,2,5]-thiadiazole(BT)and end-capped cyanide(CN)groups is firstly synthesized.Organic solar cells(OSCs)based on a well-matched typical low-bandgap polymer donor PTB7-Th give a high open-circuit voltage(VOC)of 1.05 V with power conversion efficiency(PCE)of 4.60%.The introduction of diphenyl ether(DPE)solvent additive greatly increases short-circuits current(JSC)from 8.79 to 10.43 mA cm-2 fill factor(FF)from 0.34 to 0.42 with a negligible effect on Voc,suggesting higher efficiency can be achieved by unremitting optimization of JSC and FF without significant loss in VOC.A largely enhanced external quantum efficiency(EQE)maximum from 50%to 65%over the range 500-750 nm indicate an improved charge generation in the fibril-like blend film.The photon energy loss as low as 0.6(Eg-eVOC)predict the VOC of 1.05 V might be the maximum attainable VOC,which is important for understanding the minimum driving force for maximum efficiency.2.We used this material HBC as a third component.What's more,this materials was added into the high efficiency system of PTh4FBT.By controlling the HBC proportion in the system,we designed and synthesized a series of materials,and test the photovoltaic properties of material,the experimental results show that the HBC's influence on the system can be divided into two aspects,first of all,HBC had less influence on optical and thermal stability of the original system,and the electrochemical properties.Secondly,the amount of the HBC has a significantly influence on the photovoltaic parameters,and in general speaking is a characteristic of first increase and then decrease,especially has a strong influence on Jsc,FF,PCE,open circuit.The open voltage is relatively stable.The final PCE of device is 6.077%,6.81%,7.56%,7.20%.It can be said that add some third component has the positive influence on the original system.