Structure and photoluminescence of ZnSe nanostructures fabricated by vapor phase growth

Abstract

The synthesis of ZnSe nanowires is a rapidly expanding research field with numerous applications. Key to realizing the potential of such nanowires is an ability to prepare structurally uniform defect-free material. Microstructure studies on as-grown nanostructures reveal that the structure of these nanowires are highly sensitive to the growth temperature, with higher temperature growth (750°C) resulting mostly in nanoribbons having different morphologies. Planar defects (mainly stacking faults and twins) are found to extend throughout the nanoribbons. At lower growth temperatures (650°C) structurally uniform nanowires are typically found. Photoluminescence (PL) measurements on crystalline nanowires show that the spectrum comprises two characteristic peaks corresponding to strong near band edge emission, and a weaker emission associated with defect states. However, the PL spectra of ZnSe nanoribbons which contain a high density of structural defects are dominated by defect related emission.