A simple template-free 'sputtering deposition and selective etching' process for nanoporous thin films and its application to dye-sensitized solar cells.

A facile and straightforward method is suggested to synthesize nanoporous-TiO2 thin films for dye-sensitized solar cells (DSSCs). Silver/TiO2 co-sputtering led to the formation of nanocomposite films which consisted of silver nanoclusters with surrounding TiO2 matrices, and metal particles were subsequently etched by just immersing in nitric acid. Nanoporous-TiO2 DSSCs fabricated by this simple and effective process showed power-conversion efficiencies of up to 3.4% at a thickness of only 1.8 µm, which is much superior to that of conventional nanoparticulate-TiO2 DSSCs with similar thickness.

An effective oxidation approach for luminescence enhancement in CdS quantum dots by H2O2.

The effects of surface passivation on the photoluminescence (PL) properties of CdS nanoparticles oxidized by straightforward H2O2 injection were examined. Compared to pristine cadmium sulfide nanocrystals (quantum efficiency ≅ 0.1%), the surface-passivated CdS nanoparticles showed significantly enhanced luminescence properties (quantum efficiency ≅ 20%). The surface passivation by H2O2 injection was characterized using X-ray photoelectron spectroscopy, X-ray diffraction, and time-resolved PL. The photoluminescence enhancement is due to the two-order increase in the radiative recombination rate by the sulfate passivation layer.