Wüest M. 51 Wykes M. 82 Yamaguchi M. 17 Ybarra G. 129 Yubero F ...

JUNE 28 WEDNESDAY AFTERNOON
JS1-WeA-P.4 PHOTOLUMINESCENCE AND BAND-SPLITTING IN CDS THIN
FILMS, INFLUENCE OF CDCL 2 AND THERMAL ANNEALING. O. Vigil-Galán, G.
Contreras-Puente, and J. Aguilar-Hernández. Escuela Superior de Física y Matemáticas, Instituto Politécnico
Nacional, México 07738 D.F. J. Vidal-Larramendi, and A. Arias-Carbajal. Univ. de la Habana,
43100, La Habana, Cuba. O. Zelaya-Angel. Departamento de Física, CINVESTAV-IPN, P.O.
Box 14-740, México 07360 D. F.
CdS thin films were deposited on conducting glass substrates by three different techniques: (a)
chemical bath deposition (CBD), (b) close spaced vapor transport (CSVT), and (c) laser ablation
(LA). As-grown and coated with CdCl 2 CdS-samples were thermal treated (TT) in Ar. From optical
absorption measurements the valence band splitting in cubic and hexagonal layers are observed (in
CBD and CSVT films). In the case of CdS films grown by CSVT the hexagonal wurtzite (W) crystalline
phase is observed in as-grown and TT samples, while using CBD as-grown and annealed CdS
films are cubic zincblende (ZB). For LA-CdS samples no band splitting was observed in both asgrown
and annealed samples, these two types of LA-CdS layers have W as crystalline phase. Band
splitting is characterized for the variation of the energy band gap (E g ) shift (ΔE g ) due to the spin-orbit
*
*
interaction with ΔE g = 0.069 eV, where ΔE g → Δ E g
when ZB → W, with Δ E g
= 0.081 eV, the
change is owing to the reordering of splitting levels because of the addition of the crystal field interaction.
The evolution of the crystalline quality and the ΔE g change in the three kinds of grown films,
beside optical absorption measurements, was studied from photoluminescence spectra
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