  Photovoltaic effect of double quantum dots under nonuniform light field
intensity has been studied theoretically. Comparing with the traditional p-n
type photovoltaic effect, the inhomogeneous light field provides asymmetric
potential creating polarization of electron number distribution in the
neighboring quantum dots and furthermore gives rise to net current. Current
density and efficiency of such kind solar cells are estimated to be comparable
to the traditional p-n type material based solar cells. Motion of electron is
described using quantum master equation around room temperature. The
inhomogeneous light photovoltaic effect has potential applications for the gain
of more economical solar cells.
