Optical Calculation And Simulation Of Organic Photovoltaic Cells

Organic photovoltaic cells are receiving more and more attention for their simple production process, low costs and capable of being produced in large areas. However, Organic photovoltaic cells are low in photo-electricity conversion efficiency. And the factors accounting for their photo-electricity conversion efficiency include light absorption of active layers.Light absorption of active layers is crucial to the performance of organic photovoltaic devices. So increasing the rate of light absorption of active layers can increase the use ratio of incident light, reduce the loss of absorbing light and increase photo-electricity conversion efficiency of photovoltaic devices. But there are relative fewer studies on light absorption of active layers of photovoltaic devices at present. Moreover, factors that influence light absorption of active layers remain uncertain. And laboratory methods of measuring light absorption of active layers of organic photovoltaic devices especially those with metallic films as electrodes are very few.This paper studied light absorption of active layers of organic photovoltaic devices employing theories and computer assisted tools. It consists of the following parts:1. When studying the photometric characteristics of photovoltaic devices, film optical computing theory can be used since organic photovoltaic cells have a structure of multiple films. A method for computing photometric characteristics of photovoltaic devices was found in the paper based on film optical computing theory. And factors influencing light absorption of active layers of organic photovoltaic devices were confirmed.2. Computer assisted tools must be employed to calculate photometric characteristics because of the complexity of photometric characteristics computing of organic photovoltaic devices. With the help of software named Essential Macleod, an analyzing and computing method of photometric characteristics (especially light absorption rate of active layers) of organic photovoltaic devices was found.3. Detailed simulating analysis of photovoltaic devices with the structure of ITO/PEDOT:PSS/P3HT:PCBM/Al was done centering on the influence from the change of the structure of devices on light absorption rate of the active layer of P3HT:PCBM. As a result, a device structure with the optimized absorption rate of the active layer of P3HT:PCBM. Meanwhile, the change of absorption rate of the active layer of P3HT:PCBM when a TiO2 layer was added was studied. A optimized device structure which resulted in an increase of absorption rate of the active layer of P3HT: PCBM when a TiO2 layer was added was designed. Also, the influence of TiO2 layer on devices was analyzed and a method for optimizing organic photovoltaic devices was found. Organic photovoltaic devices with the structure of ITO/P3HT: PCBM/G-PEDOT was also studied. It proved again through software simulation and experiment that adding a layer can change absorption at the active layer of the device. In this paper, absorption rate was increased by adding TiOx and ZnO layer and short-circuit current in the device was strengthened, thus the improvement of the property of devices.