Study of the correlation between structural and photoluminescence properties of CdSe thin films deposited by close-spaced vacuum sublimation

• Published in: Materials science in semiconductor processing Vol. 26; pp. 663 - 668
• Main Authors: Gnatenko, Yu.P., Opanasyuk, A.S., Ivashchenko, M.M., Bukivskij, P.M., Faryna, I.O.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2014; Elsevier
• Subjects: A1. Crystal structure; A1. Defects; A1. X-ray diffraction; A3. Polycrystalline deposition; B2. Semiconducting II–VI materials; Cadmium selenides; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition; Exact sciences and technology; Grain size; Intermetallics; Materials science; 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; Other heat and thermomechanical treatments; Photoluminescence; Physics; Semiconductors; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Sublimation; Texture; Thin films; Treatment of materials and its effects on microstructure and properties; A3. Polycrystalline deposition; B2. Semiconducting II–VI materials; A1. X-ray diffraction; A1. Crystal structure; A1. Defects; Grain size analysis; Stoichiometry; Photoluminescence; Glass; Polycrystals; Lithium; B2. Semiconducting II―VI materials; XRD; Texture; Substrat temperature; Thin films; Crystallites; n type semiconductor; Low temperature; Crystal structure; Grain size; Point defects; II-VI compound; Sublimation; Extended defects; Columnar structure; Cadmium selenides; Crystalline material; Residual impurity; Growth mechanism; Wurtzite structure
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2014.06.013

CdSe polycrystalline films were deposited by a close-spaced vacuum sublimation method at different substrate temperatures (Ts) using glass slides as substrates. At Ts≤673K the films have a structure with strong dispersion of grain size (d) (from 0.1 to 0.3μm). In this case the layer-by-layer mechanism determines the growth process of the layers. For Ts=873K they have a columnar-like structure with a clear growth texture and the average grain size d=3–4μm. The films obtained at Ts>473K are n-type and only correspond to a single wurtzite phase. The crystallites are preferentially oriented with the (102) planes parallel to the substrate. At lower temperatures the films are bi-phase. The microstress level in CdSe films obtained at Тs=873K (0.5×10−3) is considerably smaller than for the films deposited at Тs=773K (4.0×10−3). Increase of the value of Ts improves the stoichiometry of CdSe films. Analysis of the low-temperature photoluminescence (PL) spectra let us determine the nature and energy of point and extended defects in the investigated films. It was shown that the films contain Na(Li) and P residual impurities. The results of the structural and PL measurements showed that the CdSe polycrystalline films are of fairly good crystal and optical quality for Ts=873K and can be suitable for various applications.