Naphtho[2,3,a]pyrene as an efficient multifunctional organic semiconductor for organic solar cells, organic light-emitting diodes, and organic thin-film transistors

We found that naphtho[2,3,a]pyrene (NP) can be commonly used as an effective tri-functional material for three representative kinds of devices in organic electronics. In order to prove the fact, we fabricated organic solar cells (OSCs), organic light-emitting diodes (OLEDs), and organic thin-film transistors (OTFTs) using NP as their active layer. First, an optimized 80 nm-thick NP based OSC device exhibited a good power conversion efficiency of 0.48% in OSCs. Second, OLEDs with 3% NP doping showed sky blue emission and a power efficiency of 3.4 lm W−1 and a current efficiency of 4.4 cd A−1. OLEDs with 5% NP doping showed green emission and a power efficiency of 1.8 lm W−1 and a current efficiency of 3.9 cd A−1. Third, OTFTs based on NP exhibited a field-effect mobility (μFET) of 0.12 cm2 V−1 s−1, a threshold voltage (Vth) of −10.8 V, and an on/off ratio of 6.8 × 106. These results indicated that NP can be efficiently used as a donor material in OSCs, a blue and green emitting material in OLEDs, and a charge transport channel in OTFTs.