This study involves the synthesis of gallium nitride (GaN) nanoparticles (NPs) under different low temperatures using a simple chemical method. The nanoparticles are spin coated on Si substrate to fabricate the solar cell. The FESEM images obtained indicate the presence of cubic GaN nanoparticle with average diameter of 50 nm synthesized at 90 degrees C. The spin coating technique deposited n-GaN NPs/Si(111) produced a heterojunction solar cell with fill factor of 0.56 and conversion efficiency of 2.06%. Based on these results, this study proposes a novel low cost technique for the fabrication of GaN NPs solar cells. (C) 2015 Elsevier B.V. All rights reserved.