Wet-Chemical Synthesis of ZnTe Quantum Dots
- PDF / 344,635 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 44 Downloads / 219 Views
0942-W08-25
Wet-Chemical Synthesis of ZnTe Quantum Dots Jun Zhang, Zhaoyong Sun, and Jiye Fang Department of Chemistry, Binghamton University, Binghamton, NY, 13902-6000
ABSTRACT ZnTe quantum dots (QDs) have been very attractive because of their potential applications in optoelectronic devices operating in the blue-green region of the spectrum. This paper describes a convenient one-step synthesis of high-quality ZnTe QDs in high-temperature organic solution with high yield. Anhydrous zinc chloride was dissolved in phenyl ether under argon protection and oleic amine was used as coordinating agent. Complex solution of metal tellurium in trioctylphosphine (TOP) was injected into the hot reaction mixture as a source of tellurium. The reaction was complete in several minutes and the resulting QDs were isolated by centrifugation and re-dispersed in hexane. The produced spherical ZnTe QDs are monodispersed and their sizes could be controlled simply by varying the growth temperature. The morphology and phase structure were investigated using TEM and XRD. Photoluminescence (PL) spectra were also studied and quantum size effects were observed as well. INTRODUCTION Nanomaterials have drawn enormous interest from the scientific community because of their novel electronic, magnetic, optical, chemical and mechanical properties, which make them highly attractive for many important technological applications. Of the various types of nanocrystals, semiconductor nanocrystals have been the most intensively studied because of their quantum confinement effects and size- / shape-dependent photoemission.1 ZnTe quantum wells (QWs) and quantum dots (QDs) have been very attractive due to their potential applications in optoelectronic devices operating in the blue-green region of the spectrum2. The development of uniform nanometer-sized semiconductor QDs is essential in fabricating novel materials for electronic applications. Wet chemical growth of semiconductor QDs in high-temperature solution has been demonstrated as a powerful method to control the crystallinity, morphology, size and size distribution. However, such studies on the preparation of colloidal ZnTe QDs are very limited,3-6 most likely owing to a lack of appropriate synthetic approaches. Y.-W. Jun and co-workers reported a route for preparing ZnTe QDs based on thermolysis of organometallic compound.3 Direct combination reaction of metal zinc and tellurium has also been investigated for this purpose.5,6 However, all these processes need either considerably high-temperature or long reaction time.3-6 Furthermore, the morphology of resulting QDs was not satisfying. Synthesis of high quality of ZnTe QDs is still essential. In this report, we describe a convenient wet-chemical approach to synthesize size-controlled ZnTe QDs in organic solution simply using ZnCl2 and metal tellurium as the reactants. The reaction temperature is relatively low and the resulting ZnTe QDs are well crystallized with a quasi-spherical shape. We realize that oleylamine plays a very important role in the re
Data Loading...
