Preparation And Optimization Of Organic Solar Cells Based On Small Molecule Materials

In1986, C.W. Tang puts forward the double structure of organic solar cells. In1995, Heeger puts forward the concept of body heterojunction solar cells; The21st century organic small molecule solar cells photoelectric conversion efficiency over8%. After20years of development, the solar cell made another breakthrough. Throughout the development of small molecule solar cells, adjust the molecular structure and device structure is the most effective way to improve the device performance.A series of solution-processed small molecular solar cells (SMSCs) were fabricated with2,4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl](DIB-SQ) and [6,6]-phenyl-C-71-butyric acid methylester(PC7iBM) as the active layer. The cells with MoO3as anode interfacial layer and LiF as cathode interfacial layer have the maximum power conversion efficiency (PCE)2.68%. The underlying reasons are mainly attributed to the effect of MoO3layer on charge carrier collection and morphology of active layer. The effect of illumination intensity on the performance of cells was also discussed in detailed.Based on the previous research, the inverted structures of SMSCs are prepared. It is found that device with Ag as anode has greatly improved the performance, the photoelectric conversion efficiency increased by50%. Device with Ag has better performance than that with Al, which is improved nearly1times. This is because Ag has the higher work function, better hole transmission, higher reflectivity of light and better electrical conductivity than Al. The performance change of the two type of devices is consistent under different annealing conditions. After70℃annealing, the performances of the two components are both improved.Organic small material lead phthalocyanine (PbPc) nanocolumns were prepared via glancing angle deposition (GLAD) on indiumtin oxide (ITO) coated glass substrates. Organic electron acceptor materials fullerene (C60) was evaporated onto the nanocolumn PbPc thin films to prepare heteroj unction structure ITO/PbPc/C6o/Bphen/Al organic photovoltaic cells (OPVs). The interpenetrating electron donor/acceptor structure effectively enhances interface between electron donor and electron acceptor, which is beneficialto exciton dissociation. The effect of illumination intensity on the performance of OPVs was investigated by controlling the distance between light source and sample, and the Jsc of two kind of OPVs was increased along with the increase of illumination intensity.