Page 02/05/2018 10:41:24

Controlling Blend Morphology for Ultra-High Current Density in Non-Fullerene Acceptor Based Organic Solar Cells

Xin Song, Nicola Gasparini, Long Ye, Huifeng Yao, Jianhui Hou, Harald Ade, and Derya Baran​"Controlling Blend Morphology for Ultra-High Current Density in Non-Fullerene Acceptor Based Organic Solar Cells​". ACS Energy Lett.,  DOI: 10.1021/acsenergylett.7b01266​ 

Xin Song, Nicola Gasparini, Long Ye, Huifeng Yao, Jianhui Hou, Harald Ade, and Derya Baran
Blend Morphology, Current Density, Non-Fullerene Acceptor, Organic Solar Cells
2018

In this report, we highlight a system with a well-known polymer donor (PTB7-Th) blended with a narrow bandgap non-fullerene acceptor (IEICO-4F) as active layer and 1-chloronaphthalene (CN) as the solvent additive. The optimization of the photoactive layer nanomorphology yields short-circuit current density value of 27.3 mA/cm2 , one of the highest value 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 (0.71V) 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 due to increased π-π 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.​