Intrinsic Polarization of Self-Assembled Guanosine Supramolecules in GaN-Based Metal–Semiconductor–Metal Nano-Structures

The transport properties of self-assembled guanosine supramolecules (SAGS) confined within nanoscale metal electrodes on transparent GaN semiconductor substrates have been studied. The modified guanosine molecules have been used as self-assembled nanowires to realize nanoscale UV-Visible photodetectors with self-assembly length ranging from 30 to 450 nm. The ribbon-like guanosine supramolecules exhibit semiconductor properties and have polarization along its axis due to the strong intrinsic dipole moment of guanosine molecules. The charge transport through the SAGS wire with nanoscale metal-semiconductor-metal structure on passivated Ga-terminated GaN surface can be explained by Schottky type conductivity and near-surface-states. The intrinsic polarization in SAGS nano-wires changes the band-offset at the metal-semiconductor interface similar to semiconductor photodiodes.