High-quality CdTe films from nanoparticle precursors

Conference · Sun Sep 01 04:00:00 EDT 1996

OSTI ID:276869

Schulz, D L; Pehnt, M; Urgiles, E; Niles, D W; Jones, K M; Curtis, C J; Ginley, D S ^[1]

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1. National Renewable Energy Lab., Golden, CO (United States)

In this paper the authors demonstrate that nanoparticulate precursors coupled with spray deposition offers an attractive route into electronic materials with improved smoothness, density, and lower processing temperatures. Employing a metathesis approach, cadmium iodide was reacted with sodium telluride in methanol solvent, resulting in the formation of soluble NaI and insoluble CdTe nanoparticles. After appropriate chemical workup, methanol-capped CdTe colloids were isolated. CdTe thin film formation was achieved by spray depositing the nanoparticle colloids (25--75 {angstrom} diameter) onto substrates at elevated temperatures (T = 280--440 C) with no further thermal treatment. These films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Cubic CdTe phase formation was observed by XRD, with a contaminant oxide phase also detected. XPS analysis showed that CdTe films produced by this one-step method contained no Na or C and substantial O. AFM gave CdTe grain sizes of {approximately}0.1--0.3 {micro}m for film sprayed at 400 C. A layer-by-layer film growth mechanism proposed for the one-step spray deposition of nanoparticle precursors will be discussed.

• OSTI ID: 276869
• Report Number(s): CONF-960513--
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
CADMIUM IODIDES
CADMIUM TELLURIDE SOLAR CELLS
CADMIUM TELLURIDES
FABRICATION
PARTICLE SIZE
PHASE STUDIES
PRECURSOR
SODIUM TELLURIDES
SPRAY COATING