New branched hydrazones as hole transporting materials

The new hole transporting materials with molecules consisting of two hydrazone branches linked with flexible benzene ring and two hydroxyl groups containing central bridge were synthesized and investigated. These transporting materials are low molecular glasses and allow preparing stable to crystallization layers. Ionisation potential of the materials is in the range 5.04–5.43 eV. The highest hole mobility, reaching 10−4 cm2/V s at 6 × 105 V/cm electric field, was observed in the transporting material with triphenylamine moiety. These transporting materials can be used with or, in the case of a solid substrate, without binder polymer.