  Non-circuit theory drift-diffusion numerical simulation of standard
potentiostatic impedance spectroscopy (IS) is a well-known strategy for
characterization of materials and electronic devices. It implies the
time-dependent solutions from the continuity and Poisson's equations under
small perturbation of the bias boundary condition at the electrodes. But in the
case of photo-sensitive devices a small light perturbation can be also taken
modulating the generation rate along the absorber bulk. In that focus, this
work approaches a set of analytical solutions for the signals of IS and
intensity modulated photocurrent and photovoltage spectroscopies, IMPS and IMVS
respectively, from one-sided p-n junction solar cells at open-circuit.
Subsequently, a photo-impedance signal named light intensity modulated
impedance spectroscopy (LIMIS equals IMVS over IMPS) is analytically simulated
and its difference with respect to IS suggests a correlation with the surface
charge carrier recombination velocity. This is an illustrative result and
starting point for future more realistic numerical simulations.
