Studies On The Effects Of Silver Nanoparticles On The Performance Of Polymer Solar Cells

Polymer solar cells have attracted much interest because they are by far characterized of low-cost, wide variety of materials, simple process, large area and so on. However, compared to silicon-based devices, the energy conversion efficiency of polymer solar cells is very low. One of the reasons is that the active layer of a polymer solar cell is thin, only tens of nanometers, so that the light illuminating on the cell can not be fully absorbed, limiting the power conversion efficiency.The introduction of metal nanoparticles into polymer solar cells can excite the surface plasmon effect and enhance the absorption of the incident light, and therefore improve the performance of the devices. In this paper, we study the effects of silver nanoparticles on the performance of polymer solar cells based on P3HT: PCBM. The results are as follows:1. We added the silver nanoparticles into PEOOT: PSS in different mass ratios. Then, the silver nanoparticles and PEDOT: PSS were spin-coated together as the anode modification of the solar cell devices. When the mass ratio of the silver nanoparticles is0.1%, the device shows a better performance. The short-circuit current of the device increases to6.72mA/cm2, and the power conversion efficiency is1.71%. In addition, from the absorption spectra and the external quantum efficiency curves, it can be seen that the cells with silver nanoparticles absorb more incident light.2. In this experiment, the silver nanoparticles is mixed with the mixed solution of P3HT and PCBM, and the mass ratio is0.1%. The diameters of the silver nanoparticles are4nm,10nm, and20nm, respectivly. They are spin-coated as the active layer of the cell. The results show that the influences on the polymer solar cells caused by the sizes of the silver nanoparticles are different. As the diameter becomes larger, the degree of the influence on the cells becomes bigger. When the diameter of the silver nanoparticles is20nm, the performance of the device is the best, and the short-circuit current increases to6.55mA/cm.3. In order to investigate the influence of the silver nanoparticles, we put the silver nanoparticles at different locations in the solar cells, and design different device structures. It is found that when the silver nanoparticles are fully contacted with the active layer of the cell, without destroying its morphology, they can improve the performance of the polymer solar cell effectively.