Results of analysis of photovoltaic effect in ap‐njunction arising out of the two‐photon process in the presence of a constant built‐in field are presented. The short‐circuit current, the open‐circuit voltage, and efficiency of typical GaAs cells exposed to 1.17‐eV photon flux from a laser are computed. It is shown that marked improvement in the short‐circuit current and efficiency with considerable saving in material are possible with a field of the order 100 v/cm. The effect of reflection at the back face are also discussed and the possible improvement in performance with a reflecting coating of the face estimated.