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Langmuir

Title:		Preparation of nanosized ZnS-passivated CdS particle films via the MOCVD process with co-fed single source precursors
Author(s):		Hsu YJ; Lu SY;
Address:		"Department of Chemical Engineering, National Tsing-Hua University, Hsin-Chu, Taiwan 30043, Republic of China"
Journal Title:		Langmuir
Year:		2004
Volume:		20
Issue:		1
Page Number:		194 - 201
DOI:		10.1021/la0347410
ISSN/ISBN:		0743-7463 (Print) 0743-7463 (Linking)
Abstract:		"A novel approach was developed to prepare thin films of nanosized ZnS-passivated CdS particles via a metal-organic chemical vapor deposition (MOCVD) process with co-fed single source precursors of CdS and ZnS. Single source precursors of CdS and ZnS with sufficiently different reactivity, as judged from thermogravimetry analysis, were prepared and paired up to form ZnS-passivated CdS, (CdS)ZnS, and CdS-modified ZnS, (ZnS)CdS, particle films in a one-step process. For comparison purposes, sequential layer growth of CdS/ZnS and ZnS/CdS particle films was also conducted, and single compound particle films were prepared. These films were characterized with absorption spectrometry, photoluminescence spectroscopy, scanning electron microscopy, and powder X-ray diffraction spectra. The photoluminescence efficiency of the resulting composite particle film of ZnS-passivated CdS was significantly enhanced as compared to that of the plain CdS film, due to the effective passivation of surface electronic states of CdS by ZnS, a material with a higher conduction band than that of CdS. As for particle films of CdS-modified ZnS, a decay in photoluminescence efficiency was observed. The enhancement or decay in photoluminescence efficiency was much more pronounced for the passivated and modified system than for the sequential layer system, proportional to the interfacial area between the CdS and ZnS phases"
Keywords:		"Cadmium Compounds/*chemistry *Membranes, Artificial Nanostructures/*chemistry Particle Size Sulfides/*chemistry Surface Properties Volatilization Zinc Compounds/*chemistry;"
Notes:		"MedlineHsu, Yung-Jung Lu, Shih-Yuan eng Research Support, Non-U.S. Gov't 2005/03/05 Langmuir. 2004 Jan 6; 20(1):194-201. doi: 10.1021/la0347410"