Author
K. Y. Lay
Bio: K. Y. Lay is an academic researcher from North Carolina State University. The author has contributed to research in topics: Sputtering & Band gap. The author has an hindex of 3, co-authored 6 publications receiving 37 citations.
Topics: Sputtering, Band gap, Photoconductivity, Photoemission spectroscopy, Ion
Papers
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TL;DR: In this article, the linewidth of photoreflectance (PR) and photoluminescence (PL) spectra of Cd1-xMnxTe semiconductors is investigated over the range 0 ≦ x ≦ 0.4.
Abstract: The linewidth of photoreflectance (PR) and photoluminescence (PL) spectra of Cd1–xMnxTe semiconductors is investigated over the range 0 ≦ x ≦ 0.4. The linewidth of the PR spectra at room temperature is proportional to that of the low temperature PL spectra. This allows the utilization of PR at room temperature as a method of characterization for the quality of Cd1–xMnxTe crystals. The variation of the linewidth of the PL spectra with composition is dominated by alloy broadening in the range x ≦ 0.2. While for x > 0.2 crystal defects contribute to the broadening.
Die Linienbreite der Photoreflexions (PR)- und Photolumineszenz (PL)-Spektren von Cd1–xMnxTe (0 ≦ x ≦ 0,4) wird untersucht. Die Linienbreite der bei Raumtemperatur gemessenen PR-Spektren ist proportional zu der Halbwertsbreite der bei tiefen Temperaturen erhaltenen PL-Spektren. PR-Spektroskopie bei Raumtemperatur erlaubt somit eine Aussage uber die Perfektion und den Reinheitsgrad von Cd1–xMnxTe-Kristallen. Die Linienverbreiterung ist fur x ≦ 0,2 hauptsachlich durch die Legierungsbildung verursacht. Bei hoheren Mn-Konzentrationen tragen Kristalldefekte zur Verbreiterung bei.
15 citations
TL;DR: In this paper, the spin-flip energy for the Mn d electrons in Cd1 − xMnxTe from literature data is estimated and the centers of the Mn n↑ and Mn d↓ bands contributing to the photoemission and p-d transition processes at -3.5 eV and +2.0 eV, respectively, relative to the Γ8 valence band edge.
11 citations
TL;DR: In this paper, the surface of Cd(1-x)Mn(x)Te (X between 0 and 0.7) was analyzed on the basis of X-ray photoemission spectroscopy measurements.
Abstract: Native oxides on the surface of Cd(1-x)Mn(x)Te (X between 0 and 0.7) have been analyzed on the basis of X-ray photoemission spectroscopy measurements. Depth profile analysis revealed a significant increase in the thickness at higher Mn concentrations and a strong Mn segregation to the surface, respectively. Sputter-induced damage on cleaved (110)-oriented surfaces was analyzed by photoreflectance and photoluminescence measurements. The damage was found to be larger on CdTe than on the alloy. Thermal annealing showed nearly complete restoration for the surface of the alloy, while CdTe revealed irreversible modifications in the near-surface regime upon sputtering and post annealing.
6 citations
TL;DR: In this article, the authors report on near surface electronic defects generated through 5 keV Ar + ion beam sputtering on (110) oriented freshly cleaved surfaces of CdTe, CdSe y Te 1− y and Zn x Cd 1− x Te.
3 citations
TL;DR: In this paper, the results of the photoreflectance, photoconductivity, and photoluminescence studies on Mn(x)Cd(1-x)Te single crystals are discussed from the viewpoint of the utility of these compounds as gap components in multijunction solar cells.
2 citations
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235 citations
TL;DR: In this paper, the effects of ion sputtering on the surface layers of multicomponent targets are discussed, and it is shown that the changes are due to radiation-induced diffusion and segregation effects.
Abstract: Ion bombardment often leads to compositional changes in the surface layers of multicomponent targets. Such changes due to noble gas ion sputtering are discussed for InP and GaAs. The analyses show that the compositional change in InP (i.e., indium enrichment) is mainly due to preferential sputtering. In the case of GaAs. the changes are due to radiation-induced diffusion and segregation effects. Brief mention is made of compositional changes in a few other systems. The discussion on sputter-induced topography development deals mainly with InP because ion bombardment leads to dramatic topographical effects in this material. Ripple development on GaAs is also briefly discussed. Radiation damage has been well researched, and its mechanism and effects usually differ substantially when going from one semiconductor group to another. Bombardment-induced damage is briefly discussed for InP, GaAs, SiC, some II-VI semiconductors, and HgCdTe.
62 citations
11 Jan 2013-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, high quality polycrystalline CdZnTe films were prepared by aluminum induced crystallization (AIC) and radio frequency (r.f.) magnetron sputtering, and the crystallinity, morphology and optical property of both as-deposited and AIC samples were investigated by X-ray diffraction (XRD), and atomic force microscopy (AFM), as well as Raman and ultraviolet visible spectrometry.
Abstract: High quality polycrystalline CdZnTe films were prepared by aluminum induced crystallization (AIC) and radio frequency (r.f.) magnetron sputtering. The crystallinity, morphology and optical property of both as-deposited and AIC samples were investigated by X-ray diffraction (XRD), and atomic force microscopy (AFM), as well as Raman and ultraviolet–visible spectrometry. The results of XRD showed that AIC favours the preferential orientation [1 1 1], and promotes the crystallinity of the CdZnTe films. AFM micrographs show that the grain size was increased from 50 nm to 300 nm after AIC. In the Raman spectrum of CdZnTe films, the intensity of CdTe-like TO mode is enhanced after AIC. From the optical transmittance and absorption coefficient, the value of the band gap varied from 1.53 eV to 1.65 eV.
24 citations
TL;DR: In this paper, single and multiple layers of CdTe and CdMnTe, including MQW structures with well and barrier thicknesses down to 20 A, have been grown by MBE on (001) InSb.
20 citations
TL;DR: In this paper, the introduction of phosphorus and arsenic dopants into bulk Cd1−xMnxTe crystals grown by the Bridgman-Stockbarger technique has been studied with respect to the resulting electrical and optical properties.
Abstract: The introduction of phosphorus and arsenic dopants into bulk Cd1−xMnxTe crystals grown by the Bridgman–Stockbarger technique has been studied with respect to the resulting electrical and optical properties. Uncompensated acceptor concentrations as high as 1015–1016 cm−3 are obtained. Samples with a Mn composition in the range 0.10
19 citations