In this issue we include research on developments in silicon for solar cells, still the overwhelming material of choice in this industry, and this includes a paper on the novel ‘black silicon’. The use of TiO2 in dye-sensitised solar cells (DSSC’s) attracts a number of papers, as does research on chalcogenide materials including CIGS and CZTS, which are both of very active interest. Reflecting another modern development, we include papers on allpolymer and hybrid polymer solar cells, together with a number of more specialised papers.