Abstract

AbstractPhotoconductive atomic force microscopy is employed to study the nano­scale morphology and optoelectronic properties of bulk heterojunction solar cells based on small molecules containing a benzofuran substituted diketopyrrolopyrrole (DPP) core (3,6‐bis(5‐(benzofuran‐2‐yl)thiophen‐2‐yl)‐2,5‐bis(2‐ethylhexyl)pyrrolo[3,4‐c]pyrrole‐1,4‐dione, DPP(TBFu)2, and [6,6]–phenyl‐C71‐butyric acid methyl ester (PC71BM), which were recently reported to have power conversion efficiencies of 4.4%. Electron and hole collection networks are visualized for blends with different donor:acceptor ratios. Formation of nanostructures in the blends leads to a higher interfacial area for charge dissociation, while maintaining bicontinuous collection networks; conditions that lead to the high efficiency observed in the devices. An excellent agreement between nanoscale and bulk open‐circuit voltage measurements is achieved by surface modification of the indium tin oxide (ITO) substrate by using aminopropyltrimethoxysilane. The local open‐circuit voltage is linearly dependent on the cathode work function. These results demonstrate that photoconductive atomic force microscopy coupled with surface modification of ITO substrate can be used to study nanoscale optoelectronic phenomena of organic solar cells.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.