Well-aligned hierarchical TiO2 tubular macrochannel arrays (HTTMAs) with high surface area have been synthesized via a facile one-step ammonia hydrothermal synthesis process without using any structure-directing templates. The typical samples are made of an assembly of macrochannels with uniform...

Cu, Al, and Ti films of ~ 10 nm thickness were deposited on porous silicon (PS) at room temperature using Filtered Cathodic Vacuum Arc system and annealed at 800°C for 10 min in vacuum. The PS layers were obtained by anodization of Si wafer. X-ray photoelectron spectroscopy, photoluminescence...

Photoluminescence, photoabsorption, and X-ray photoelectron spectroscopic study revealed that an optical transition of porous silicon from red-shift to blue-shift, and Si-2p binding energy transition from low to high at a critical anodization temperature, 343 K. Possible origin for the reverse...