Relation between Interfacial Band-Bending and Electronic Properties in Organic Semiconductor Pentacene

There is still a challenge in organic electronics to effectively tailor interfacial electronic structures for achieving desired electronic properties for optoelectronic devices. This study realizes the tuning of interfacial electronic structures in organic semiconductor pentacene by employing substrates with different work functions. Pentacene layers show downward band-bending with a low work function, flat band with a middle work function, and upward band-bending with a high work function. The formation of band-bending is explained by the electrostatic potential according to the Fermi level position. Different interfacial electronic structures can influence the carrier transport across the interface. Their diodes show different rectifying behaviors due to band-bending, and ohmic transport is observed for the flat band structure. This work is a promising exploration to realize desired functions of semiconductor devices by tailoring interfacial electronic structures.