Introduction to organic polymer solar cells

1. An important difference between organic polymer solar cells and inorganic solar cells is that tightly bound excitons (electron-hole pairs) appear in organic solar cells. In this case, the active layer material in organic solar cells is relatively low. Due to the low dielectric constant, this kind of tightly bound excitons are called Frenker excitons, and their bound energy is usually between 0.3-1 eV. Such a large bound energy prevents excitons from ionizing under the use of an electric field. For organic electroluminescence devices, this phenomenon reduces the probability of excitons entering the non-radiation attenuation orbit and ensures the high efficiency of electroluminescence. 2. Organic polymer solar cells make the photoelectric conversion process a new step compared with inorganic solar cells, which is completely different from lithium ion polymer batteries. Therefore, the photogenerated excitons in organic solar cells have a certain energy loss when they are separated. , Generally 0.3-0.4eV. This characteristic makes researchers generally believe that the theoretical maximum efficiency should be lower than that of inorganic solar cells. It is generally believed that the lowest unoccupied molecular orbital (LUMO) of the donor and the highest occupied by the acceptor in the heterojunction The energy difference between the molecular orbitals (HOMO) is the driving force for the dissociation of Frenkd excitons. The factors that really limit the efficiency of organic solar cells seem to be very simple, but they are actually very complicated. It is necessary to conduct in-depth discussions on this issue. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Basic information and performance introduction of curved polymer batteries