Near Infrared Emission Band and Origin in Ni(II)-Doped CdS Nanoribbons by CVD Technique

• Published in: Journal of physical chemistry. C Vol. 117; no. 34; pp. 17777 - 17785
• Main Authors: Kamran, Muhammad Arshad, Liu, RuiBin, Shi, Li-Jie, Zou, BingSuo, Zhang, Qingling
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 29.08.2013
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Fullerenes and related materials; Infrared and raman spectra and scattering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum confinement; Raman spectra; Two-level systems; Doping; Photoluminescence; Optical transition; XRD; Hybridization; Nanostructures; Nickel additions; Light sources; Nanometer scale; Wires; Solar cells; Scanning electron microscopy; Band structure; Electronic properties; Impurity density; Digital simulation; Quantum effect; Nanotape; X-ray spectra; Dispersive spectrometry; Field emission electron microscopy; Semimagnetic semiconductors; CVD; Near infrared radiation; Lifetime; Electronic structure; Electron state; Density functional method
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp402831n

In this work, we report the synthesis of high-quality Ni-doped CdS nanoribbons via chemical vapor deposition (CVD) method. The as-synthesized samples were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) techniques. The presence of Ni ions in CdS nanoribbons has been confirmed through energy-dispersive X-ray spectroscopy (EDX) and nonuniform peak shifting of Raman spectrum. Except the bandedge emission, the photoluminescence (PL) properties of Ni-doped CdS nanoribbons are dominated by a broad near-infrared (IR) emission band centered around 1.61 eV. This transition corresponds to two high levels of d electronic state of Ni with strong p-d hybridization between Ni ions and S, which seldom happens in usual dilute magnetic semiconductors (DMS). The p-d hybridization is confirmed by the simulation of electronic band structure in Ni-doped CdS wires with first-principle calculation and PL lifetime measurements, which blocked the optical transitions of lowest d levels. This near-IR emission shift with varied dopant concentration in Ni-doped CdS nanoribbons has been observed for the first time in this CdS semiconductors, which could be accounted for by the quantum confinement effect of NiS cluster in CdS; this material may be used as nanoscale light sources tuned by the dopant, possibly for solar cell if highly doped.