The Preparation And Performance Of ZNO Based Organic/Inorganic Hybrid Solar Cells

With the rapid development of global economy, energy shortages and carbon emissions has become increasingly prominent. And then the development of renewable energy also becomes more important and urgent. In recent years, Organic/inorganic hybrid solar cells as a promising has been widespread concern. Compared with conventional solar cells, hybrid solar cells have many advantages, such as its material is cheap and it can form a thin film at low temperature by spin coating, screen printing, inkjet printing. New type of solar cells are considered to be the ideal choice for replacing the inorganic solar cells.ZnO based organic/inorganic hybrid solar cells are popular, because ZnO can grow at low temperature and low production cost. ZnO has high electron mobility and non-toxic. In this paper, we first studied the effect of growth conditions on the ZnO nanostructure size and density, and focuses on the different dimensions of ZnO nanostructrues, ZnO surface modification treatment, annealing, oxygen plasma treatment and other air aging affect the efficiency of the device. We found all the treatment we did of ZnO can improve the performance of the device. Specific studies are as follows:1. We produced ZnO nanorod with hydrothermal method on ITO substrate which to be coated with ZnO nanocrystalline.We observed ZnO morphology and size changes by adjusting the concentration of reactants and reaction time. As a basis for the preparation of the ITO/ZnO/P3HT/Ag hybrid solar cell, we obtain the optimum ZnO nanorods size and density by comparing the efficiency of the cell;2. We prepared the hybrid solar cells structured as ITO/ZnO/P3HT/Ag. Throgh the study of the annealing treatment and the plasma treatment respectively of ZnO, we found the best treatment conditions is annealing for 1h at 400℃;3. We prepared the hybrid solar cells structured as ITO/ZnO/P3HT:PCBM/Ag. The performance of the as-fabricated devices is improved by annealing temperature and time of active layer, surface modification of ZnO with PSBTBT. Optimized device of ITO/ ZnO nanorod/P3HT:PCBM/Ag device with PSBTBT surface modification and air exposure reaches an efficiency of 2.02% with a short-circuit current density, open-circuit voltage and fill factor of 13.23 mA cm-2,0.547 V and 28%, respectively, under AM 1.5 irradiation of 100 mW cm-2, and exhibited a 7-fold in efficiency by surface modification of ZnO compared with the unmodified ITO/ZnO nanorods/P3HT:PCBM/Ag device;4. We also study the organic solar cells structured as ITO/P3HT:PCBM /Al.Organic solar cells made of P3HT as electron donor and PCBM as electron acceptor with different thickness of active layer were fabricated and analysized. From the Jsc-V characteristics of the devices we found the thickness of the active layer influences the efficiency of the device greatly. When blocking layer of PEDOT:PSS and T1O2 were added to the device, we found they had different effect on the performance of the device characterized by I-V and adsorption analysis, the introduction of PEDOT:PSS improve the efficiency of the device while TiO2 does not change the performance evidently, the detail was discussed.