Preparation And Performance Optimization Of P3HT:PCBM Polymer Solar Cells

With the development of the economy and society, the problems of energy shortage and environmental pollution have become increasingly prominent. As one kinds of the new energy, solar energy has received wide attention due to its advantages such as renewable, clean and convenience. Especially, organic polymer solar cells have been developed rapidly and received wide attention in recent years for its advantages such as light weight, low cost, large-area fabrication and mechanically flexibility. But it needs to be further optimized because of its disadvantages such as low power conversion efficiency and short lifetime.In this thesis, the bulk heterojunction polymer solar cells were fabricated with the P3HT acting as an electron donor material, and PCBM was acting as electron accepted material. In order to improve the performance of the devices, modified layers were inserted into organic layer/cathode interface and organic layer/anode interface, respectively. Furthermore, the AZO and AZO/Ag/AZO flexible transparent conductive thin films were used as anode to fabricate bulk heteroj unction polymer solar cells. The feasibility and advantages of the flexible polymer solar cells by employing AZO and AZO/Ag/AZO flexible transparent conductive thin films as anode were also discussed. The work includes the following content:I. A LiF modified layer, PCBM modified layer and PCBM/LiF modified layer were inserted into the interface of organic layer/cathode, respectively. The process techniques, materials of modified layer and thickness of modified layer on the devices performance were discussed in systematically. The mechanism of improvement of the devices using different modified layer were also analyzed in details. The devices which using PCBM/LiF to modify the organic layer/cathode interface showed the best performance and the highest repeatability with the short-circuit current density of 9.59 mA/cm2 and power conversion efficiency of 2.11%.â…¡. A PEDOT:PSS modified layer, AZO modified layer and AZO NPs:PEDOT: PSS modified layer were inserted into the organic layer/anode interface, respectively. The process techniques, material of modified layer and thickness of modified layer on the devices performance were discussed in system. The mechanism of improvement of the devices using different modified layer were also analyzed in details. The results showed that, the short-circuit current density of the devices was up to 9.62mA/cm2 when using AZO NPs to modify organic layer/anode interface. Meanwhile, the short-circuit current density of the devices was further improved to 11.08mA/cm2 when using AZO NPs/PEDOT:PSS to modify organic layer/anode interface.â…¢. AZO and AZO/Ag/AZO transparent conductive films were prepared on the PET flexible substrates, and its photoelectric properties, mechanical properties were explored in details. Based on AZO and AZO/Ag/AZO flexible transparent conductive thin films the polymer solar cells were fabricated, and the performances of the flexible devices based on AZO or AZO/Ag/AZO anode were analyzed and characterized, respectively. It was found that the flexible polymer solar cells based on AZO/Ag/AZO anode exhibited better mechanical properties and higher power conversion efficiency. Its power conversion efficiency is as high as 2.06% after bending for 500 times.