Nanoscale Characterization of Tetrabenzoporphyrin and Fullerene-Based Solar Cells by Photoconductive Atomic Force Microscopy

The subtle role of molecular design in determining organic photovoltaic performance is demonstrated with the aid of photoconductive atomic force microscopy. Each layer of OPV devices with a p/i/n architecture containing BP and PCBM or PCBNB is characterized using conducting and photoconducting AFM to gain insight as to why these devices perform differently in the bulk. The results illustrate how a slight change in the chemical structure of the layers can have a large impact in the film morphology, phase separation, and the device performance.