In this work, we report the growth of vertically aligned bulk InGaN nanowires (NWs) on r-plane sapphire substrate by metal organic chemical vapor deposition (MOCVD). Through the optimization process of growth conditions, such as growth temperature and pressure, we obtained high density InGaN NWs consisting of one (000 (1) under bar) polar- and two equivalent {1 (1) under bar 01} semi-polar planes. We have shown the highest InGaN NWs wire density of 8 x 10(8) cm(-2), with an average diameter of 300 nm and a length of 2 mu m. From results of photoluminescence (PL) at 30 K and 300 K, we observed the intense and broad emission peak from InGaN NWs at around 595 nm, and confirmed that the luminescence could be tuned from 580 nm to 660 nm by controlling the indium flow (TMIn) rate. Our results indicate that MOCVD-grown InGaN NWs can be effective absorbers of the blue-green range of solar spectrum and may be one of the good candidates for high efficiency photovoltaic devices targeting at blue-green photons. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.