BODIPY derivatives as n-type organic semiconductors: Isomer effect on carrier mobility

In the present work, two dipyrro-boradiazaindacenes (BODIPY) derivatives functioning as novel high-performance organic semiconductors are investigated by theoretical method. These two isomeric complexes are demonstrated to have large electron-transfer mobility, which means they are favor to be n-type organic semiconductors. The highest electron-transfer mobility appears at the same packing style in two crystals. The intermolecular distances of the packing style are nearly same, 4.994 angstrom in crystal 1 and 5.283 angstrom in crystal 2. However, their electron-transfer mobility changes significantly. The mobility of crystal 2 with better planar molecular structure is 0.291 cm(2) V-1 s(-1), which is 13 times larger than that of crystal 1 as 0.022 cm(2) V-1 s(-1). The significant difference of carrier mobility is ascribed to the little structural difference of these two isomers. It has been demonstrated that both crystal 1 and 2 show remarkable anisotropic behavior. This study will undoubtedly provide a new understanding of isomerization on designing novel organic semiconductors. (C) 2011 Elsevier B. V. All rights reserved.