The effects of Sn:Te ratio on optical properties of SnTe NPs

AuthorsSara Khosravi Cgandomani- Bahram Khoshnevisan- Ramin Yousefi
JournalJournal of Luminescence
Paper TypeFull Paper
Published At2018-7-3
Journal GradeISI
Journal TypeTypographic
Journal CountryIran, Islamic Republic Of

Abstract

The effects of Te source concentration on morphology, structural, and optical properties of the SnTe nanoparticles (NPs) were investigated. The SnTe NPs were synthesized by a simple, cost-effective, and fast co-precipitation method. X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images of the samples indicated that, crystallite and particle size of the NPs were changed by changing of Te source concentration. Fourier-transform infrared spectroscopy (FTIR) results also revealed that, some new vibration modes were appeared by varying of Te source concentration. Ultraviolet-visible-near infrared (UV-Vis-NIR) and room temperature photoluminescence (PL) spectroscopy results showed that, Te source concentration caused a big change in optical properties of the NPs. The UV–Vis–NIR results indicated that, the absorption peaks of the samples were placed in the NIR region. The PL results of the samples included several defect energy levels that performed violet, green, and red emissions. Characterization of the pure NPs by PL with different excitation power showed that, the violet and green emissions were from an alloy of oxide layer and SnTe that was formed on the surface of the NPs. On the other hand, the red emission was from donor-acceptor pair (DAP).