%0 Journal Article
%T Controlling Blend Morphology for Ultrahigh Current Density in Nonfullerene Acceptor-Based Organic Solar Cells
%J -
%D 2018
%R https://doi.org/10.1021/acsenergylett.7b01266
%X In this Letter, we highlight a system with a well-known polymer donor (PTB7-Th) blended with a narrow band gap nonfullerene acceptor (IEICO-4F) as the active layer and 1-chloronaphthalene (CN) as the solvent additive. Optimization of the photoactive layer nanomorphology yields a short-circuit current density value of 27.3 mA/cm2, one of the highest values in organic solar cells reported to date, which competes with other types of solution-processed solar cells such as perovskite or quantum dot devices. Along with decent open-circuit voltage (0.71 V) and fill factor values (66%), a power conversion efficiency of 12.8% is achieved for the champion devices. Morphology characterizations elucidate that the origin of this high photocurrent is mainly the increased ¦Ð¨C¦Ð coherence length of the acceptor, the domain spacing, as well as the mean-square composition variation of the blend. Optoelectronic measurements confirm a balanced hole and electron mobility and reduced trap-assisted recombination for the best devices
%U https://pubs.acs.org/doi/10.1021/acsenergylett.7b01266