Simple dye-sensitized solar cells were developed using blackboard chalk as a substrate for mixed ZnO and SnO(2) films that were sensitized with Mercurochrome (Merbromine) dye. Graphite pencil "leads" were used as counter electrodes for the cells and the electrolyte consisted of an aqueous solution of iodine and potassium iodide that was gelled with a disinfectant containing quaternary ammonium compounds and cyanoacrylate adhesive (Superglue(R)). The open circuit potential of constructed cells was typically 0.50-0.64 V and the short circuit current varied between 0.5 and 2.0 mA cm(-2). The cells were developed as an educational resource that could be simply and safely constructed in a home or school environment with readily accessible materials. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.