GaAs nanowire (NW)-based p–n photovoltaic devices, with two distinct p and n spatialdistributions and where Te was the n-dopant, have been studied by impedance spectroscopy in the103–107 Hz frequencyrange and the − 1.5–1.5 V bias range. For a large n-core/p-shell overlap region within NWs in a coaxialgeometry, the p–n junction properties (DC rectification and p–n depletion capacitance) arefound to prevail. The impedance data at low bias for both NW devices show largefrequency dispersions with relaxation frequencies that are compatible with carrierre-emission times from traps due to GaAs surface states. An increasing conductance withincreasing frequency for low bias is observed, suggesting hopping transport throughlocalized states. For large bias the conductance increases exponentially with bias and isfrequency independent, indicating conduction through extended states in this regime.