title: Band mapping across a pn-junction in a nanorod by scanning tunneling microscopy.
abstract: We map band-edges across a pn-junction that was formed in a nanorod. We form a single junction between p-type Cu2S and n-type CdS through a controlled cationic exchange process of CdS nanorods. We characterize nanorods of the individual materials and the single junction in a nanorod with an ultrahigh vacuum scanning tunneling microscope (UHV-STM) at 77 K. From scanning tunneling spectroscopy and correspondingly the density of states (DOS) spectra, we determine the conduction and valence band-edges at different points across the junction and the individual nanorods. We could map the band-diagram of nanorod-junctions to bring out the salient features of a diode, such as p- and n-sections, band-bending, depletion region, albeit interestingly in the nanoscale.
authors.affiliation: Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
authors.forename: Abhijit
authors.initials: A
authors.lastname: Bera
authors.forename: Sukumar
authors.initials: S
authors.lastname: Dey
authors.forename: Amlan J
authors.initials: AJ
authors.lastname: Pal