Band Gap Tuning and Room-Temperature Photoluminescence of a Physically Self-Assembled Cu2O Nanocolumn Array

The morphology modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. In this work, growth and morphology evolution of a well-separated Cu2O nanocolumn array is explored by tuning deposition angle and substrate rotation speed in oblique angle deposition (OAD). X-ray diffraction and photoluminescence measurements reveal that crystal quality and optical properties crucially depend on the morphology of the nanostructures. An intense room-temperature photoluminescence (RTPL) signal at 525 nm indicates that the Cu2O nanocolumn arrays exhibit strong green luminescence. The morphology-dependent band gap tuning makes this approach of great potential for nanoscale optoelectronic applications.