PHOTON-ABSORBING CHARGE-BRIDING STATES IN OGRANIC PHOTOVOLTAIC DEVICES OFDIKETOPYRROLOPYRROLE-BASED DONOR AND PCBM

摘要

Guiding principles to design highly optimized organic photovoltaic devices that achieve high power conversion efficiencies are strongly desired. To obtain a useful guideline, we have investigated the photo- and electrochemical properties of five diketopyrrolopyrrole (DPP) derivatives and four DPP derivatives containing double DPP blocks by ab initio calculations (1,2). To investigate the factors that influence the IQE, investigations on charge recombination, hole transfer, and charge transfer induced by photoabsorption were conducted for the complexes of each DPP derivative and PCBM. We may suggest that the change in the dipole moment in the complex of donor and acceptor molecules is a promising guideline for designing new donor molecules to improve the short-circuit current and power conversion efficiencies.