title: Synthesis of ZnSe and ZnSe:Cu quantum dots by a room temperature photochemical (UV-assisted) approach using Na2SeO3as Se source and investigating optical properties.
abstract: In this study, ZnSe and ZnSe:Cu quantum dots (QDs) were synthesized using Na2SeO3as the Se source by a rapid and room temperature photochemical (UV-assisted) approach. Thioglycolic acid (TGA) was employed as the capping agent and UV illumination activated the chemical reactions. Synthesized QDs were successfully characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) and UV-visible (UV-vis) spectroscopy, Fourier transform-infrared (FT-IR), and energy dispersive X-ray spectroscopy (EDX). XRD analysis demonstrated the cubic zinc blend phase QDs. TEM images indicated that round-shaped particles were formed, most of which had a diameter of about 4 nm. The band gap of the ZnSe QDs was higher than that for ZnSe in bulk. PL spectra indicated an emission with three peaks related to the excitonic, surface trap states and deep level (DL) states. The band gap and QD emission were tunable only by UV illumination time during synthesis. ZnSe:Cu showed green emission due to transition of electrons from the Conduction band (CB) or surface trap states to the2T2acceptor levels of Cu2+. The emission was increased by increasing the Cu2+ion concentration, such that the optimal value of PL intensity was obtained for the nominal mole ratio of Cu:Zn 1.5%.
authors.affiliation: Department of Physics, Faculty of Science, Vali-e-Asr University, Rafsanjan, Iran.
authors.forename: R
authors.initials: R
authors.lastname: Khafajeh
authors.affiliation: Department of Physics, Faculty of Science, Vali-e-Asr University, Rafsanjan, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Molaei
authors.affiliation: Department of Physics, Faculty of Science, Vali-e-Asr University, Rafsanjan, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Karimipour
mesh_terms: D003300:Copper / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D010777:Photochemistry / Q000379:methods; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D049408:Luminescent Agents; D018036:Selenium Compounds; D017967:Zinc Compounds; D003300:Copper; C044696:zinc selenide
keywords: Cu-doped; ZnSe; optical properties; photochemical