||Spectroscopic Determination of Charge Formation Efficiency of Organic Photovoltaic Cells
Moritomo, Yutaka ,
Yonezawa, KouheiYasuda, Takeshi
Molecular Crystals and Liquid Crystals
31 , 2015-12 , Taylor and Francis, Inc
The internal quantum efficiency (ΦIQ) of an organic photovoltaic (OPV) cell is governed by plural processes, i.e., the carrier formation process at the D/A interface and the carrier transfer process toward the collector electrode. Then, ΦIQ can be decomposed into the carrier formation (ΦCF) and carrier transfer efficiencies (ΦCT). By combination of femtosecond time-resolved and electrochemical spectroscopies, we determined absolute values of ΦCF of F8T2/PC71BM, P3HT/PCBM, and PTB7/PC71BM solar cells. We found that ΦCF at 400 nm of the F8T2/PC71BM cell is higher than those of the P3HT/PCBM, and PTB7/PC71BM cells, although ΦIQ at 400 nm is the lowest.