Investigation On Organic/Polymer Solar Cells Based On Polytetrafluoroethylene

Now the mankind is faced with serious energy crisis and the continuousdeterioration of the ecological environment, and changes the existing structure of theenergy, the development of green and clean energy has become the importance issueof all the countries in the world. The sun is free, renewable source of energy, andsolar cell is one of the main forms of solar energy utilization. The utilization of solarenergy might, therefore, provide an approach for solving the energy crisis producedby the consumption of irreplaceable fossil fuels at a steadily increasing rate. Manydeveloped countries are actively developing low-cost thin-film photovoltaictechnology. In fact, monocrystalline silicon solar cell, polycrystalline silicon solar celland amorphous silicon solar cell are leading products. But many factors, such asdesign difficult, relatively complex technology and the high cost, are restricting therenewable energy is fully utilization the biggest obstacle. The development of lowcost, environment friendly, resources-rich the next generation of solar cell is the coreissue of photovoltaic technology. Organic/polymer solar cell with its low cost, lightweight, simple production process and other advantages, is gradually attention.Aiming at the organic/polymer solar cells, this paper carried out the followingresearch.1. In Chapter Three, we inserted a layer of PTFE film into the ITO electrode tomanufacture the device structure of ITO/PTFE/PEDOT:PSS/P3HT:PCBM/Al with adouble buffer layer. Then we compared it with the photovoltaic devices without PTFEfilm and found that the short-circuit current of the photovoltaic devices with PTFEfilm was improved and the open circuit voltage was increased from0.43V to0.54V.When the thickness of the PTFE film is3nm, the power conversion efficiency of thedevice was raised40%than the device with no PTFE film.2. In Chapter Four, we tested the photovoltaic devices which structure wasITO/PTFE/P3HT:PCBM/Al, and the results showed that the short-circuit current ofthe device increased and then decreased with the increase of the thickness of thePTFE film for its greater charge-blocking characteristics. The open circuit voltage of the photovoltaic devices improved from0.35V to0.55V with the increase of thePTFE film thickness, because the PTFE buffer layer enhanced ITO surface workfunction. We achieved the power conversion efficiency of the device as high as2.27%when the PTFE film was2nm.3. In Chapters Five, the small organic molecules devices based onpolytetrafluoethylene were closely studied. We investigated the structure ofITO/PTFE/CuPc/C₆₀/BCP/Al and chose the structure ofITO/PEDOT:PSS/CuPc/C₆₀/BCP/Al and ITO/CuPc/C₆₀/BCP/Al as comparisondevices. We found that the performance of the device with PTFE buffer layer wasbetter than the device with PEDOT:PSS buffer layer. With the same open circuitvoltage, the short-circuit current of the device with0.3nm PTFE film raised75%thanthe device without PTFE film. The open circuit voltage of the device increased withthe rise of the PTFE film thickness. The device of0.5nm PTFE film being exposed5min in UV has exhibited the best performance with the power conversion efficiencyof1.58%.In conclusion, we have obtained high short-circuit current, open circuit voltageand power conversion efficiency of photovoltaic devices that usedpolytetrafluoethylene as the buffer layer, and the performance of the device is greatlyimproved. So polytetrafluoethylene material will have potential applications inphotovoltaic cells.