Dielectric relaxation of CdSe nanoparticles

被引：11

作者：

Das, Sayantani ^{[1
]}

Dutta, Alo ^{[2
]}

Ghosh, Binita ^{[2
]}

Banerjee, Sourish ^{[1
]}

Sinha, T. P. ^{[2
]}

机构：

[1] Univ Calcutta, Dept Phys, Kolkata 700009, India

[2] Bose Inst, Dept Phys, Kolkata 700009, India

来源：

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS | 2014年 / 75卷 / 11期

关键词：

Chemical synthesis; X-ray diffraction; Dielectric properties; QUANTUM DOTS; IMPEDANCE; CDTE; CDO; NANOCRYSTALS; SPECTROSCOPY; TEMPERATURE; CONSTANTS; TIME;

D O I：

10.1016/j.jpcs.2014.06.008

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Nanoparticles of cadmium selenide (CdSe) have been synthesized by soft chemical route using mercaptoethanol as a capping agent. X-ray diffraction and transmission electron microscope measurements show that the prepared sample belongs to sphalerite structure with the average particle size of 25 nm. The band gap of the material is found to be 2.1 eV. The photoluminescence (PL) emission spectra of the sample are measured at various excitation wavelengths. The PL spectra appear in the visible region, and the emission feature depends on the wavelength of the excitation. Impedance spectroscopy is applied to investigate the dielectric relaxation of the sample in a temperature range from 323 to 473 K and in a frequency range from 42 Hz to 1.1 MHz. The complex impedance plane plot has been analyzed by an equivalent circuit consisting of two serially connected R-CPE units, each containing a resistance (R) and a constant phase element (CPE). The dielectric relaxation of the sample is investigated in the electric modulus formalism. The temperature dependent relaxation times obey the Arrhenius law. The Havriliak-Negami model is used to investigate the dielectric relaxation mechanism in the sample. The frequency dependent conductivity spectra are found to obey the power law. (C) 2014 Elsevier Ltd. All rights reserved.

引用

页码：1245 / 1251

页数：7

共 48 条

[41] Electric modulus and interfacial polarization in composite polymeric systems [J].