Our group is interested in environmental applications of nanoscale semiconductors, especially in low-cos solar energy conversion. Much of our work has concerned the dye sensitized solar cell (DSS), for which we have invested novel architectures of composite materials to obtain optimal properties for harvesting properties for harvesting electrons from photoexcited dye molecules and quickly extracting those electrons before they are lost to recombination processes, to maximize the efficiency of converting solar power to electrical power. We are also devising dye-attached nanocatalysts to circumvent voltage losses in the DSSC. We are in the early stages of applying some of our nanostructures to recently emerged perovskite solar cells (PSC).