A simple solution method has been proposed that deals the specific impacts of solvent characteristics on the growth of zinc oxide (ZnO) nanoparticles. The aggregation of particles is a major drawback in the hydrothermal method, and it is suppressed by using a less polar reaction solvent. ZnO particles obtained from a lower polarity indexed reaction medium show a very strong UV band-edge emission with an almost negligible deep level emission when compared to ZnO particles isolated from the higher polarity index of the medium. For the application is concerned, highly dispersible ZnO nanomaterials are used as an active material for dye-sensitized solar cells (DSSC), due to their higher internal surface area. Additionally, the deposition of ZnO layers on commercially available GaN-based blue light emitting diodes (LEDs) is fabricated to improve the light extraction efficiency, without disturbing the basic structure of the LED. The layer thickness and light transmission at a specific wavelength are the major factors which can improve the light emission from LEDs. (C) 2009 Elsevier B.V. All rights reserved.