Raman studies of composition and structural ordering in Hg1-xCdxTe

Publisher Website
Google Scholar
Abstract
Information on both the alloy composition and the lattice properties of Hg1-xCdxTe for x-values between 0.20 and 0.31 have been obtained by resonance Raman spectroscopy with laser photon energies between 2.35 and 2.7 eV. In addition to the HgTe-like TO and LO modes and the CdTe-like LO mode, the authors have studied the resonance behaviour of the mode at 133 cm-1, which has been identified as originating from the preferential clustering of 3Hg and 1Cd about the Te. They find that the intensity of this peak for various bulk and epitaxially grown samples is unusually large only near the E1 resonance. Pulsed laser annealing with an Nd:YAG-pumped dye laser strongly suppresses this mode in all samples, suggesting that extremely rapid epitaxial regrowth may inhibit the 3:1 cluster formation. Detailed comparisons are presented for Hg1-xCdxTe films grown by liquid phase epitaxy (LPE), molecular beam epitaxy (MBE) and metal-organic chemical vapour deposition (MOCVD) procedures.