Cavallini, Anna[Physics Department, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy]
Polenta, Laura[Physics Department, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy]
Rossi, Marco[Physics Department, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy]
Richter, Thomas[Institute of Thin Films and Interfaces (ISG1) and cni - Centre of Nanoelectronic Systems for Information Technology, Research Center Julich]
Marso, Michel[Institute of Thin Films and Interfaces (ISG1) and cni - Centre of Nanoelectronic Systems for Information Technology, Research Center Julich]
Meijers, Ralph[Institute of Thin Films and Interfaces (ISG1) and cni - Centre of Nanoelectronic Systems for Information Technology, Research Center Julich]
Calarco, Raffaella[Institute of Thin Films and Interfaces (ISG1) and cni - Centre of Nanoelectronic Systems for Information Technology, Research Center Julic]
Lüth, Hans[Institute of Thin Films and Interfaces (ISG1) and cni - Center of Nanoelectronic Systems for Information Technology, Research Centre Jülich, 52425 Jülich, Germany]
[en] In this letter we report on spectral photoconductivity (PC) on different sections of single MBE-grown GaN nanowhiskers of diameters ranging on the order of 100 nm. The photoconductivity spectra show, besides the band-gap related transition, deep-levels corresponding to the yellow, green, and blue bands. A strong spatial localization of specific photocurrent peaks has been observed, indicating that the defects responsible for such transitions are distributed inhomogeneously along the column growth direction.