Jyoti Jaiswal

Determination of optical constants including surface characteristics of optically thick nanostructured Ti films: analyzed by spectroscopic ellipsometry

In the present work, optically thick nanostructured titanium (Ti) films of thickness ranging from ∼100 to 900 nm were deposited on a glass substrate by DC magnetron sputtering at room temperature. Microstructural and surface properties of the samples were studied by x-ray diffraction and x-ray photoelectron spectroscopy (XPS). The morphological results revealed a systematic normal grain growth mechanism with increasing thickness analyzed by a scanning electron microscope. The influence of thickness on film surface roughness has been investigated by atomic force microscopy (AFM). The optical dispersion behavior was examined by spectroscopic ellipsometry (SE) over the long wavelength range of 246-1688 nm. The experimentally observed SE parameters were theoretically fitted with Drude-Lorentz and Bruggeman effective medium approximation theory. The surface properties of the Ti film measured by XPS and AFM were further accounted for in the optical model to determine optical constants (n and k) and the obtained results are expected to be the best available for bulk Ti metal.

Optical and other physical properties of hydrophobic ZnO thin films prepared by dc magnetron sputtering at room temperature

Highly ordered and hydrophobic zinc oxide thin films have been synthesized by dc magnetron sputtering on the glass substrates at room temperature (RT). We have determined the influence of deposition parameters on the optical and other physical properties of the films, and the correlation between their microstructural and optical properties. Films have preferred (002) orientation, an average crystallite size ≤26 nm, and rms surface roughness ≤14 nm. The water contact angle of 120° exceeds previous measurements by over 10°–20°. Dispersion of the refractive index is analyzed in terms of the Wemple-DiDomenical single-oscillator model, and the third-order nonlinear optical parameters are calculated using the Tichy and Ticha relation. Refractive indices of 1.9686 at 540 nm are near the bulk value of 2.0041. Produced at RT, these highly ordered films may be promising candidates for compact optoelectronic devices.Highly ordered and hydrophobic zinc oxide thin films have been synthesized by dc magnetron sputtering on the glass substrates at room temperature (RT). We have determined the influence of deposition parameters on the optical and other physical properties of the films, and the correlation between their microstructural and optical properties. Films have preferred (002) orientation, an average crystallite size ≤26 nm, and rms surface roughness ≤14 nm. The water contact angle of 120° exceeds previous measurements by over 10°–20°. Dispersion of the refractive index is analyzed in terms of the Wemple-DiDomenical single-oscillator model, and the third-order nonlinear optical parameters are calculated using the Tichy and Ticha relation. Refractive indices of 1.9686 at 540 nm are near the bulk value of 2.0041. Produced at RT, these highly ordered films may be promising candidates for compact optoelectronic devices.

Structural and optical characteristics of in-situ sputtered highly oriented 15R-SiC thin films on different substrates

In this work, we have reported the in-situ fabrication of nanocrystalline rhombohedral silicon carbide (15R-SiC) thin films by RF-magnetron sputtering at 800 °C substrate temperature. The structural and optical properties were investigated for the films grown on four different substrates (ZrO2, MgO, SiC, and Si). The contact angle measurement was performed on all the substrates to investigate the role of interfacial surface energy in nucleation and growth of the films. The XRD measurement revealed the growth of (1 0 10) orientation for all the samples and demonstrated better crystallinity on Si substrate, which was further corroborated by the TEM results. The Raman spectroscopy confirmed the growth of rhombohedral phase with 15R polytype. Surface characteristics of the films have been investigated by energy dispersive x-ray spectroscopy, FTIR, and atomic force microscope (AFM) to account for chemical composition, bonding, and root mean square surface roughness (δrms). The optical dispersion behavior of 15R-SiC thin films was examined by variable angle spectroscopic ellipsometry in the wide spectral range (246–1688 nm), including the surface characteristics in the optical model. The non-linear optical parameters (χ3 and n2) of the samples have been calculated by the Tichy and Ticha relation using a single effective oscillator model of Wemple and Didomenico. Additionally, our optical results provided an alternative way to measure the ratio of carrier concentration to the effective mass (N/m*). These investigated optical parameters allow one to design and fabricate optoelectronic, photonic, and telecommunication devices for deployment in extreme environment.In this work, we have reported the in-situ fabrication of nanocrystalline rhombohedral silicon carbide (15R-SiC) thin films by RF-magnetron sputtering at 800 °C substrate temperature. The structural and optical properties were investigated for the films grown on four different substrates (ZrO2, MgO, SiC, and Si). The contact angle measurement was performed on all the substrates to investigate the role of interfacial surface energy in nucleation and growth of the films. The XRD measurement revealed the growth of (1 0 10) orientation for all the samples and demonstrated better crystallinity on Si substrate, which was further corroborated by the TEM results. The Raman spectroscopy confirmed the growth of rhombohedral phase with 15R polytype. Surface characteristics of the films have been investigated by energy dispersive x-ray spectroscopy, FTIR, and atomic force microscope (AFM) to account for chemical composition, bonding, and root mean square surface roughness (δrms). The optical dispersion behavior of 15...

The Role of the Substrate on Photophysical Properties of Highly Ordered 15R-SiC Thin Films

We report on the structural optimization and photophysical properties of in situ RF-sputtered single crystalline 15R-SiC thin films deposited on various substrates (ZrO2, MgO, SiC, and Si). The role of the substrates on the structural, electronic, and photodynamic behavior of the grown films have been demonstrated using x-ray diffraction, photoluminescence (PL) and time-resolved photoluminescence spectroscopy. The appropriate bonding order and the presence of native oxide on the surface of the grown samples are confirmed by x-ray photoelectron spectroscopy measurement. A deep-blue PL emission has been observed corresponding to the Si-centered defects occurring in the native oxide. Deconvolution of the PL spectra manifested two decay mechanisms corresponding to the radiative recombination. The PL intensity and carrier lifetime were found to be substrate- dependent which may be ascribed to the variation in the trap-density of the films grown on different substrates.

Correction to: The Role of the Substrate on Photophysical Properties of Highly Ordered 15R-SiC Thin Films

The wrong issue and volume number are indicated on the published article. This article appears in Volume 47, Number 9.