Study On Photovoltaic Characteristic Of PDPP3T Based Polymer Solar Cells And Characterization Techniques Of Nano-ZnO Film

ABSTRACT:The ways to improve PSC which include polymer materials, interface optimization and phase separation have been attentioned and studied by the researchers, such as crystallization、domain size、materials mobility、molecular orientation and hierarchical structures are of grate importance. In this paper, auther will regard the hierarchical structure as s starting point to improve the polymer conversion efficiency of PSC, what the photovoltaic characteristic of narrow bandgap polymer and intermediate layer (ZnO/PEDOT) of the tandem cells are prepared and studied will lay the foundation for the prepation of the tandem cells. PDPP3T is new narrow bandgap (1.3eV) and high mobility polymer with infrared region of the solar spectrum(600nm-1000nm) absorption, which is the best optional system to prepare the tandem solar cells with a complementation spectrum of P3HT:PCBM (300nm-650nm). So, we will specific the work with the research of PDPP3T:PCBM system and intermediate layer.Firstly, the study on photovoltaic characteristics and doping density of PDPP3T:PCBM: When the PDPP3T:PCBM system device is characterized in the thickness of85nm, the external quantum efficiency and photocurrent reaches the maximum. It suggests charge carrier transport and collection obtained in the space charge region of finite length. The result suggest that Annealing^different solvent treatment and slow drying method leads a better phase separation and PCBM crystallization, which decreases device doping density and defect state density. The research is found that the decreasing doping density will increase the device current density and reduce the device voltage, indicating that the doping density will play an important parameter as characterizing the performance of polymer device. This result will lead an important step for the tandem cells.Secondly, the study on characterization techniques of Nano-ZnO Film:the intermediate connecting layer (ZnO/PEDOT) is an Electron-hole transporting layer that connect multijunction cells of the devices. In this chapter, the device structure of ITO/PEDOT/P3HT:PCBM/ZnO/Al is prepared by synthesize and characterize the Nano-ZnO thin film. The research suggests that the Nano-ZnO solution of15mg/ml plays the best performance through IV test. The photocurrent density for a device has upgraded to4.139mA/cm^2by annealing120°for one hour, which offer a better interface with active layer ohmic contact. So it will lay the foundation for the prepation of the tandem cells.