A single layer anti-reflective (AR) mesoporous silica nanoparticles coating on Cu(In,Ga)Se-2 (CIGS) thin film solar cells has been fabricated. Unlike traditional vacuum deposited AR coatings, this nanoparticle coating is applied using simple wet deposition techniques. In this study we investigate the structural properties and anti-reflection effects of the nanoparticle coating on the CIGS solar cell. The reduction in reflection and increase in the short circuit current shows the potential of this nanoparticle coating to compete with current technology. (C) 2014 Elsevier B.V. All rights reserved.