Experimental Evaluation of Hole Mobility in Organic Semiconductors Based on Benzo[f][1,2,5]oxadiazolo[3,4-b]thieno[3,2-h]quinoxalines

For the first time, the hole mobility values for benzo[f]- and naphtho[1,2-f]-annelated [1,2,5]oxadiazolo[3,4-b]thieno[3,2-h]quinoxalines were determined experimentally by using the space-charge-limited current method. Analysis of the X-ray diffraction data for naphtho[1,2-f][1,2,5]oxadiazolo[3,4-b]thieno[3,2-h]quinoxaline revealed significant π–π stacking, which may be attributed to enhanced electron mobility. These findings are further supported by the observed low hole conductivity values, which reached 4.10 × 10−9 cm2·V−1·s−1. Therefore, polycyclic compounds based on the furazano[3,4-b]pyrazine core can be considered a convenient scaffold for developing both electron and hole transport materials in various organic photovoltaic devices.