AVS 45th International Symposium
    Thin Films Division Thursday Sessions
       Session TF-ThA

Paper TF-ThA7
Structure and Electronic Properties of the Novel Semiconductor Alloy Cd@sub 1-x@Cu@sub x@Te

Thursday, November 5, 1998, 4:00 pm, Room 310

Session: Ex-situ Characterization of Thin Films
Presenter: S.J. Jiménez-Sandoval, Cinvestav-IPN, Mexico
Authors: S. López-López, Cinvestav-IPN, Mexico
G. Torres-Delgado, Cinvestav-IPN, Mexico
S.J. Jiménez-Sandoval, Cinvestav-IPN, Mexico
O. Jiménez-Sandoval, Cinvestav-IPN, Mexico
R. Castanedo-Pérez, Cinvestav-IPN, Mexico
Correspondent: Click to Email
In this work is presented an investigation of the structural and electronic properties of the novel semiconductor alloy Cd@sub 1-x@Cu@sub x@Te. The samples were prepared as thin films by rf sputtering on substrates made of Corning glass. X-ray diffraction patterns showed that the incorporation of Cu into CdTe did not affect significantly its lattice parameter. The band gap of the alloys measured by optical transmission spectroscopy was smaller than that of pure CdTe by only 50 meV, approximately. Due to its sensitivity to local atomic order, the samples were studied by micro-Raman spectroscopy. The transverse and longitudinal optic modes regularly observed in CdTe were also found in the Cd@sub 1-x@Cu@sub x@Te samples with frequency variations lower than 2 cm@super -1@, and no additional modes were observed. From the Raman experiments it was also determined that the incorporation of Cu precluded the formation of Te aggregates, which are commonly detected in CdTe thin films and bulk samples. The Cd@sub 1-x@Cu@sub x@Te films were p-type and, remarkably, it was found in some cases resistivity reductions by seven orders of magnitude with respect to pure CdTe films grown under the same conditions. This is opposite to the observed behavior on Cu-doped CdTe samples where copper acts detrimentally for electronic transport. Our studies indicated that the samples with the best properties were those in which the copper content was below ca. 7.0 at%.