In a Schottky junction solar cell, the barrier height plays an important role in determining various cell parameters. In this study, we have modified the Schottky barrier height by growing InP quantum dots in-situ on (100) p-Si by metal organic chemical vapor deposition technique. It is observed that the barrier height depends on the size and shape of the nanostructures. The shape of the grown nanostructures is determined by atomic force microscopy and cross sectional transmission electron microscopy. Presence of parabolic and flat plateau like structures rather than spherical was observed and analyzed. Under 1-sun AM 1.5, the device with a barrier height of 0.71 eV, is found to show a conversion efficiency of 3.89% with open circuit voltage of 0.51 V and short circuit current density of 13.29 mA/cm(2). This is an increase of 2.82% compared to control devices where no nanostructuring is used to modify the barrier height. (C) 2014 Elsevier B.V. All rights reserved.