We have prepared polymer solar cells with improved performance by inserting a simple reflector layer prepared by spin-coating. The reflector consists of TiOx and SiOx layers inserted between glass substrate and indium tin oxide electrode. All the processing is performed at temperatures not exceeding 150 degrees C. The transmittance of the structure can be adjusted by changing the spinning speed and the number of layers used. The use of a reflector structure results in a significant increase in the short circuit current density, on average from 7.6 mA cm(-2) to 8.9 mA cm(-2). (C) 2012 Elsevier B.V. All rights reserved.