Spectroscopic and structural characterization of electrochemically grown ZnO quantum dots

Abstract

We report a novel method for the synthesis of stable, OH free zinc oxide quantum dots, using an electrochemical route. The optical properties of these quantum dots were studied at room temperature, by taking the optical absorption and luminescence spectra. The band gap luminescence is predominant in ZnO quantum dots synthesized by the present technique, while the green defect induced luminescence, typical of ZnO, is strongly quenched. The role of defects in photoluminescence emission is discussed.

Effect of [OH–] Linkages on Luminescent Properties of ZnO Nanoparticles

“…The origin of this blue emission in ZnO nanoparticles is not yet fully acknowledged in literature. In literature it has been attributed to carbon impurities attached to the surface of nanoparticles [30] or to interstitial oxygen ions implanted in ZnO matrix [31][32][33]. Furthermore such a luminescence has also been reported in nanoparticles synthesized in an excess [OH -] environment [22].…”

Synthesis, Self-assembly and Optoelectronic Properties of Monodisperse ZnO Quantum Dots

“…Mahamuni and co-workers [51][52][53][54] have reported a lot of their work on synthesizing ZnO QDs using electrochemical growth method. Figure 4 shows TEM images of as-prepared ZnO QDs with average sizes of 6.1nm and 9.3nm [51]. In typical preparation of ZnO QDs, an electrochemical bath consisted of a mixture of acetonitrile, tetrahydrofuran (THF) and tetra-octyl-ammonium-bromide (TOAB).…”

“…By far, various kinds of synthetic approaches have been realized in fabricating such small ZnO QDs, which can be roughly divided into chemical methods and physical methods. Chemical methods involves sol-gel method [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], hydrothermal growth [41][42][43][44], thermal decomposition [45][46][47][48][49][50], electrochemical method [51][52][53][54], while physical methods involves PLA or PLD [55][56][57][58][59], MOCVD [60][61][62][63], sputtering [64][65][66], FSP method [67][68][69][70] and VPT deposition [71,72]. At present, all the methods can be divided into two parts as follow:…”

Synthesis and Characterization of Pure Zinc Oxide Nanoparticles and Nickel Doped Zinc Oxide Nanoparticles

“…Because of its exceptional optical and electrical properties, zinc oxide has been extensively used in many technological applications such as thin film transistors [1], gas sensors [2], transparent conductor [3], Bio medical [4] and piezoelectric application [5].Various methods have been employed by researchers for synthesis of ZnO nano structured materials like nonionic polymer assisted thermolysis [6], conventional solid state reaction [7], sol-gel method [8], electron beam deposition [9], an electro chemical route [10], chemical coprecipitation method [11] etc. Among these methods, chemical co-precipitation method is the best one, because it is simple, less expensive and has high yield rate.…”