The performance of organic dyes in dye-sensitized solar cells: From theoretical calculation to experiment

Herein, two phenothiazine-based organic molecules PTZ-6 and PTZ-19 were designed and synthesized. Firstly, the molecular structures were optimized through density functional theory (DFT) using CAM-B3LYP method and 6-311G (d) group based on Gaussian09 program. And the UV–vis absorption spectrum of the dye molecules also being simulated with time dependent density functional theory (TD-DFT). Subsequently, we calculated the open circuit voltage (VOC), filling factor (FF) and other data of the devices with these two dyes, the simulated Power Conversion Efficiency (PCE) values are 5.9% and 7.2% for PTZ-6 and PTZ-19. In addition, to verify the reliability of our calculation method, these two dyes were synthesized, and a detailed analysis was conducted on the photophysical and electrochemical properties of two dye molecules, as well as their device performance. The PCE obtained from the experiment were 3.99% and 4.39%, respectively. The experimental data is close to the theoretical data, and the regularity of the performance differences between these two dyes has been well verified. Our research provides a relatively reliable theoretical calculation method for designing and predicting the performance of organic dyes for dye-sensitized solar cells (DSSCs).