Incorporating UV-sensitive electron transport layers (ETLs) into organic bulk heterojunction (BHJ) photovoltaic devices dramatically impacts short-circuit current (Jsc) and fill factor characteristics. Resistivity changes induced by UV illumination in the ETL of inverted BHJ devices suppress bimolecular recombination producing up to a two orders of magnitude change in Jsc. Electro-optical modeling and light intensity experiments effectively demonstrate that bimolecular recombination, in the form of diode current losses, controls the extracted photocurrent and is directly dependent on the ETL resistivity.
Bibliographical noteFunding Information:
Support for this work is from NSF (Solar: Grant No. DMR-0934433) and from UNC-Chapel Hill Institute for the Environment Carolina Energy Fellow. Acknowledgment is made to the donors of The American Chemical Society Petroleum Research Fund (PRF) (Grant No. 49187-DNI10) for partial support of this research. We thank Professor Frank Tsui, Will Rice, Matt Wolboldt, Dr. Matthew K. Brennaman, Ralph L. House, Dr. Kwan Skinner, and Dr. Ethan Klem for stimulating conversations.
ASJC Scopus subject areas
- Physics and Astronomy(all)