Picene, an isomer of pentacene with an armchair arrangement of benzene rings, can be regarded as a fragment of a graphene sheet. Picene is more chemically-stable than pentacene because of its larger energy band gap (3.3 eV) and larger ionization potential (5.5 eV).
p-Channel FET characteristics of the picene thin-film FET can be significantly enhanced by exposure to O2, with the field-effect mobility (μ) reaching 1.4 – 3.2 cm2V–1 s–1. It is believed that the highest two picene orbitals are inverted due to the strong interactions between the singly-occupied oxygen π orbital and the highest occupied orbital of picene [2, 3]. The μ value of the picene thin-film FET can be further improved to 5 cm2V–1 s–1 under 500 torr of O2, the highest μ reported to date for an organic thin-film FET.
Like graphite or other 2D materials, picene can be intercalated with metal (e.g. potassium). The magnetic properties of the Kx picene solids also show superconducting transitions at 7 K and 18 K [4].