Infrared and Raman spectroscopic study ofZn1−xMnxSematerials grown by molecu

Abstract

Molecular beam epitaxy and optical investigation of Zn 1Ϫx Mn x Se epilayers over a large composition range (xϭ0 -0.78), grown on GaAs ͑001͒ substrates, are reported. The far-infrared ͑FIR͒ reflectance and Raman scattering were performed to characterize the film quality and study their optical and electrical properties. FIR and Raman data provide experimental evidence on the intermediate-mode phonon behavior for Zn 1Ϫx Mn x Se with x up to 0.78. Theoretical modeling fits of FIR spectra lead to the determination of optical parameters such as mode frequency, strength, damping constant, and electrical properties of dielectric constant, carrier concentration, mobility, conductivity, and effect mass, and their dependence on the Mn composition. Values of force constants of F MnSe ϭ17.1ϫ10 4 dyn cm 1 and F ZnSe ϭ14.7ϫ10 4 dyn cm Ϫ1 , and the high-frequency limit dielectric constant of MnSe, ⑀ ϱ ϭ5.4, are obtained. ͓S0163-1829͑99͒07147-7͔

Phonon properties and doping of Zn1–xMnxSe epilayers grown by molecular‐beam epitaxy

“…According to the extended classification scheme for the optical phonon modes in mixed alloys (Genzel et al [10]), the observed behavior in our Zn 1-x Mn x Se samples (0 ≤ x ≤ 0.43) corresponds to an 'intermediate-mode' behavior. This result agrees with previously published findings [11].…”

Evolution of local structures in polycrystallineZn1−xMgxO(<

“…Raman spectroscopy is known to be useful for examining compositional disorder and/or the presence of strain within semiconductor alloys. 3,4,5,6,7,8 In previous Raman studies on wurtzite type crystals, the peak position and shape of the E high 2 phonon mode have been used to investigate the effects of sample grain size, heterogeneous components, and defects. 5,6 PDF analysis provides a powerful probe of local non-periodic atomic displacements in the short range, and is a suitable complement to the k-space refinement technique.…”

Phonon and free-charge-carrier properties ofZn1−xMnxSeepilayers grown by molecular-beam epitaxy

“…A similar behavior for Zn 1−x Mn x Se mixed crystals was also observed in previous studies. [15][16][17][18][19] Figure 5 demonstrates the effect of the layer thickness on the shape of the reststrahlen band. It compares the simulated FIR reflectivity spectra for an undoped ZnSe/ GaAs sample with different ZnSe layer thicknesses.…”

“…6,7,9 The latter makes it a suitable candidate for divising spin filters 10 or utilizing it as a spin aligner in spin-based optoelectronic devices ͑see, e.g., In the present work, unpolarized reflection measurements in the far-infrared to the mid-infrared spectral range are employed in combination with electrical Hall effect measurements in order to investigate the phonon and free-chargecarrier properties of Zn 1−x Mn x Se as a function of Mn content and free-electron concentration. Previous reports on longwavelength optical phonons in bulk and thin film Zn 1−x Mn x Se epilayers investigated via Raman scattering [15][16][17] and/or using far-infrared reflection and transmission studies 18,19 demonstrated that Zn 1−x Mn x Se exhibits an intermediate-mode behavior for the optical phonons. However, there was only experimental evidence for ZnSe-like and MnSe-like phonon features.…”