Berlin 2012 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 16: II-VI Semiconductors I

HL 16.5: Talk

Monday, March 26, 2012, 16:00–16:15, EW 202

A new model for the O_Te-V_Cd complex in CdTe — •Dirk Bastin¹, Edward Lavrov¹, Jörg Weber¹, Jürgen Schneider², Alex Fauler², and Michael Fiederle² — ¹Technische Universität Dresden, 01062 Dresden, Deutschland — ²Freiburger Materialforschungszentrum, 79104 Freiburg, Deutschland

CdTe single crystals treated in CdSO₄ vapor at 850 ^∘C are investigated by IR absorption. Two local vibrational modes (LVM) at 1096.8 (ν₁) and 1108.4 cm⁻¹ (ν₂) appear in the sample as the result of the thermal treatment. The modes were previously identified by Chen et al. as vibrations of the O_Te-V_Cd complex [G. Chen et al., Phys. Rev. Lett. 96, 035508 (2006)]. We detect in our samples additional LVMs with intensities which match the natural abundance of the sulfur isotopes. The reported dependence of the absorption intensities of ν₁ and ν₂ from the oxygen concentration of the samples points to a model of an sulfur-oxygen complex of the vibrating center. From the intensities of the IR absorption involving the ¹⁸O isotope, we conclude that two oxygen atoms contribute to the LVMs.