Measurement of the Mean Inner Potentials of Anthracene and Naphthalene

The mean inner potential in metals, insulators, and semiconductors provides fundamental information regarding the electronic structure of the material. Here, we measure the mean inner potentials of the two archetype linear polyacenes: anthracence and naphthalene. We determine the mean inner potentials of single crystalline anthracene of 5.9 V (+/- 0.3 V), and naphthalene of 5.4 V (+/- 0.3 V) based on analysis of Kikuchi patterns observed using high-pressure reflection high energy electron diffraction. We show that the inner potential of a range of organic molecular semiconductors can be estimated from their diamagnetic susceptibilities.