The current study investigates the effects of conjugation length and heteroatom substitutions on the internal reorganization energy (λ), adiabatic IP, and adiabatic EA of a series of oligoaceno[2,3-c]chalcogenophenes using density functional theory. The calculated IP and EA values of cyanated pentaceno[2,3-c]chalcogenophenes indicate that these compounds have high potential for use as air-stable ambipolar OFET materials. Their λ + and λvalues are markedly smaller than those of well-known ambipolar air-stable DCMST and BTIFDMT, indicating that they are promising materials for use in high-performance ambipolar air-stable OFETs. The calculated results show that attaching electron-withdrawing groups on the compounds with extended conjugation length is an effective strategy to achieve ambipolar air-stable OFETs.

The internal reorganization energies (λ + ) associated with the transfer of a hole in a series of p-type five-ring heteroarenes were investigated using density functional theory (DFT). The λ + value of the first model compound, tetraceno[2,3-c]thiophene (TcTH), is 31 meV less than that of its analogue, the well-known tetraceno[2,3-b]thiophene (TbTH), because of the fusing of thiophene in a nonbonding fashion. The λ + value of cyanated TcTH (DCN-TcTH) is as low as 50 meV. For a given degree of electronic coupling (t), the electron exchange rate (k et) of DCN-TcTH is 2.2 times that of TbTH. This study strongly indicates that TcTH and its derivatives are promising materials for fabricating high-mobility p-type organic field effect transistors.

Orbital promises: Frontier orbital analyses showed that the small lambda(+) value of 8,17-di-n-hexylbenzo[1,2-k;4,5-k']difluoranthene (DH-BDF) is owed to the nonbonding character of the BDF framework. The calculated adiabatic ionic potential and hole mobility indicates that this compound is a p-type air-stable organic field-effect transistor, which promises to be a soluble, stable and high-performance p-type organic semiconductor.

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