Devices
based upon semiconductor nanowires provide many well-known
advantages for next-generation photovoltaics, however, limited experimental
techniques exist to determine essential electrical parameters within
these devices. We present a novel application of a technique based
upon two-photon induced photocurrent that provides a submicrometer
resolution, three-dimensional reconstruction of photovoltaic parameters.
This tool is used to characterize two GaAs nanowire-based devices,
revealing the detail of current generation and collection, providing
a path toward achieving the promise of nanowire-based photovoltaic
devices