Organic-inorganic interfaces: principles of quasi-epitaxy of a molecular semiconductor on inorganic compound semiconductors

We present a comprehensive set of molecularly-resolved scanning tunneling microscopy data on the fundamentals of quasi-epitaxy of 3,4,9,10-perylenetetracar☐ylic dianhydride (PTCDA) on graphite, Se-passivated GaAs(100) (2 × 1), and InAs(001) (4 × 2). Each of these substrates has smooth large-scale morphology; however, they possess differing surface energies that are seen to affect the growth mode of the PTCDA films. The mechanism of point-on-line coincidence is found to describe the orientation of all PTCDA films whereby the overlayer unit cell is matched one-dimensionally to substrate atomic planes.