One-pot room temperature synthesizing Cu- and Mn-doped ZnSe nanocrystals by a rapid photochemical method

Abstract

In this work, a one-pot, rapid, green and room temperature photochemical synthesis of transition metal (TM; Cu, Mn)-doped ZnSe nanocrystals (NCs) was reported. NCs were successfully characterized using Fourier transform-infrared (FT-IR), photoluminescence (PL) and UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), X-ray diffractometry (XRD) and energy dispersive X-ray spectra (EDX). FT-IR spectra confirmed the capping of ZnSe by thioglycolic acid (TGA) molecules. XRD and TEM analysis demonstrated zinc blend phase NCs with an average size of around 3 nm. Band gap of ZnSe NCs was about 3.6 eV which it was decreased by increasing the illumination time. PL spectra of ZnSe NCs showed a broad emission with two peaks located at 380 nm and 490 nm related to excitonic and trap states emission, respectively. For ZnSe:Cu NCs, excitonic emission disappeared completely and PL intensity of trap states emission increased with the increase in the Cu[Formula: see text] ion concentration so that for precursor ratio of Cu:Zn 1%, optimal value of PL intensity was obtained. For ZnSe:Mn NCs, the excitonic emission decreased gradually with the increase in the impurity concentration whereas trap state emission increased. Moreover, a peak about 590 nm was appeared from 4T1-6A1 transition of the Mn[Formula: see text] impurity, demonstrating the Mn incorporation inside the ZnSe NCs structure.