Research Of Organic Solar Cells Based On Soluble Small Molecule Materials

Organic solar cells(OPVs)have attracted much attention owing to low price,light weight,flexibility,large-area photovoltaic devices.In the past few years,the remarkable advances have been achieved with the power conversion efficiencies(PCEs)higher than 11% for single-junction devices.The significant progresses are primarily benefits from synthesis photoactive materials,or ameliorate method for fabricate organic solar cells devices,or optimize device structure.This paper is based on small molecules SDF as donor,studied and fabricated high-performance of organic solar devices.By optimizing the concentration of the donor,the ratios of SDF to PC71 BM,and incorporating SDF into PTBT: PC71 BM system to increase absorption spectrum of organic solar cells.Thus increasing of charge generation for achieves high performance of organic photovoltaic cell.The main findings of this article are the following:1.Based on SDF: PC71 BM system,study the effect of donor concentration on the device performance based on SDF: PC71 BM system.The results show that reducing the donor concentration of active layer could improve the performance of the device.When the concentration of donor decreased from 20 mg / ml to 8 mg / ml,the short-circuit current of the device upgrade from 4.12 mA/cm2 to 6.10 mA/cm2,the open-circuit voltage VOC is 0.97 ± 0.02 V,the filling factor FF upgrade from 22.28% to 25.27%,and power conversion efficiency upgrade from 0.90% to 1.50%.2.Based on SDF: PC71 BM system,Study the effect of weight ratio of D/A on the device performance.The results show that increasing the ratio of the receptor in the active layer can significantly improve the performance of the device.When For The D/A weight ratio of SDF: PC71 BM from 1: 2 change into 1: 5,the short-circuit current of the device upgrade from 6.10 mA/cm2 to 7.76 mA/cm2,the open-circuit voltage VOC is 0.97 ± 0.02 V,the filling factor FF upgrade from 25.27% to 35.69%,and power conversion efficiency upgrade from 1.50% to 2.60%.3.The SDF as third component was doped in traditional PTB7: PC71 BM blend film,study the effect of doped concentration for the device performance.The results show that doping favorable amount SDF material can significantly improve the performance of binary solar cells.The device based on P TB7: PC71 BM show a short circuit current is 15.09 mA / cm2,an open circuit voltage is 0.71 V,a filling factor FF is 66.08%,and a a power conversion efficiency is 7.09%.When the ratio of PTB7: S DF: PC71 BM is 1:0.1: 1.5,1:0.2:1.5,the performance of device were significantly improved.PCE increased to 8.05%,8.28%,JSC increased to 16.33 mA / cm2,16.59 mA / cm2,VOC increased to 0.73 V,filling factor FF was increased 67.65%,67.92%,respectively.When keep on increase concentration of SDF,the VOC of device gradually increased,but J SC and FF are decreasing gradually,resulting in PC E cut down.The research content of this paper provides a reference for the selection materials and the optimization of device structure for organic solar cell.