Scanning photocurrent microscopy (SPCM) is a powerful technique for investigating local electronic structures and
charge transport in semiconductor nanowires. Here we apply this technique to explore colloidal PbSe nanowires and
VO2 nanobeams. Field effect transistors incorporating single colloidal PbSe nanowires were fabricated. A fast, sensitive
polarization-dependent photoresponse was observed. SPCM of as-grown PbSe nanowires showed a downward band
bending towards the metal electrodes, consistent with their p-type nature. At 54 °C, SPCM of VO2 nanobeams revealed
band bending at the metallic/insulating domain boundaries. At room temperature, we observed photocurrent spots in the
middle of the VO2 nanobeams, indicating local electric fields likely caused by defects.