Observation of Unusual Homoepitaxy in Ultrathin Pentacene Films and Correlation with Surface Electrostatic Potential

Pentacene second layer grows with a twist (similar to 76 degrees) on the first layer, while the third and subsequent layers show commensurism with their respective underlayers. The preferred twisting of the second layer on the first layer gives rise to epitaxial and non-epitaxial domains which also reflect in the surface electrostatic potential measurements.