Study On Blocking Layers Of Carriers To Improve The Performance Of Organic Solar Cells

The polymer solar cells see as an renewable source because of the many advantages, such as the light weight, the low cost of the fabrication and the easy procedure on flexible substrates. The bulk-heterojunction solar cells based on electron donor and acceptor is low energy consumption and high production. The performance of the polymer solar cells has been bettered by introduction of bulk-heterojunction concept as an active layer, increased the area of the D/A interface, promoted the improvement of the performance of the device. The most common ways to improve the performance of the device are looking for the right materials and optimized the structure of the device. For example, we can add the barrier layer between the electrodes and the active layer. The main researches of this paper include the following two parts:In this article, the bulk-heterojunction solar cells based on PCBM:P3HT, and we put out the correlation curve about the carriers moving in the device. We found the leakage current, and this is disadvantageous to collection of the carriers. In order to improve the performance of the device, we try to add two barrier layers to decrease the leakage current. The research shows that: when the thickness of the barrier layers less than 0.5 nm, the performance of the device increasing as the increase of the thickness of the barrier layers; and when the thickness of the barrier layers more than 0.5 nm, the performance of the device doesn’t change obviously. At the same time, as the decrease of the leakage current, the geminate recombination enhance, which doesn’t play a major role. Adding the barrier layers actually contribute to decrease the leakage current is proved by simulation computation.