Article
Materials Science, Multidisciplinary
S. Delice, M. Isik, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: Optical characterization of PbWO4 single crystals grown by the Czochralski method was performed using spectroscopic ellipsometry experiments. The tetragonal scheelite structure and the energy dependence of the complex dielectric function of the crystal were determined. The refractive index, dielectric constant, and optical band gap were calculated, and two critical points in the dielectric function were identified.
Article
Optics
S. Delice, M. Isik, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: The optical properties of PbMoO4 single crystals grown by Czochralski method were investigated. Spectroscopic ellipsometry measurements and X-ray diffraction measurements were conducted to obtain the relevant data. The study found that the real part of the complex dielectric function of PbMoO4 increased up to 4.0 eV and then decreased suddenly, and the optical band gap was calculated as 3.09 eV. Two critical points with energies of 3.57 and 4.34 eV were determined from the analysis of the second-energy derivative spectra of the dielectric function.
Article
Optics
Daesuk Kim, Vamara Dembele, Sukhyun Choi, Gukhyeon Hwang, Saeid Kheiryzadehkhanghah, Chulmin Joo, Robert Magnusson
Summary: This paper describes a dynamic spectroscopic imaging ellipsometer (DSIE) that utilizes a monolithic polarizing interferometer to provide spatio-spectral ellipsometric phase map data at a speed of 30Hz. The ultrafast mapping capability of the spectroscopic ellipsometer is demonstrated by measuring a patterned 8-inch full wafer with a spatial resolution of less than 50 x 50 μm² in an hour.
Article
Polymer Science
Laura Hrostea, Georgiana-Andreea Bulai, Vasile Tiron, Liviu Leontie
Summary: The ellipsometric analyses in this paper provide a novel approach to investigate the optical properties of ternary organic blends. By varying the weight ratio of blended materials, the relative permittivity of active layers can be controlled and tuned. The study demonstrates the tunability of the refractive index and highlights the potential of ternary blends in enhancing solar conversion devices.
Article
Physics, Applied
Joshua D. John, Shun Okano, Apoorva Sharma, Satoru Nishimoto, Noritoshi Miyachi, Kunitaka Enomoto, Jun Ochiai, Ichitaro Saito, Georgeta Salvan, Tomoaki Masuzawa, Takatoshi Yamada, Daniel H. C. Chua, Dietrich R. T. Zahn, Ken Okano
Summary: Superlattice structures have unique electrical and optical properties suitable for applications like quantum cascade lasers and ultra-sensitive photo-detectors, but their fabrication requires specialized techniques like molecular beam epitaxy. Using rotational evaporation, films with alternating layers of amorphous selenium and arsenic selenide were successfully fabricated and their optical properties were investigated using spectroscopic ellipsometry. The models showed distinct absorption energy levels in the multi-layer structure, confirming the transitions between quantum well levels due to the superlattice structure.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
M. Isik, S. Delice, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: The study discusses the structural and optical characteristics of Bi12TiO20 single crystals grown by Czochralski method, revealing sharp X-ray diffraction patterns and Raman spectra peaks. The direct bandgap energy of Bi12TiO20 was found to increase as temperature decreased. The temperature-dependent bandgap characteristics were analyzed using Varshni and O'Donnell-Chen models, determining the absolute zero bandgap energy, rate of change of bandgap energy, and average phonon energy.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Crystallography
Xuan Au Nguyen, Thi Minh Hai Nguyen, Tae Jung Kim, Long Van Le, Tung Hoang Nguyen, Bogyu Kim, Kyujin Kim, Wonjun Lee, Sunglae Cho, Young Dong Kim
Summary: Dielectric tensors on the cleavage plane of biaxial SnSxSe1-x alloys were reported using spectroscopic ellipsometry in the energy region from 0.74 to 6.42 eV, revealing strongly anisotropic optical responses along different principal axes. An approximate solution provided anisotropic dielectric functions along zigzag and armchair directions. The blue shifts of critical point energies with increasing S composition were observed, and the fundamental bandgap for Se = 0.8 and 1 in the armchair axis was found to arise from band-to-band transitions at the M-0 minimum point.
Article
Physics, Applied
Chen Chen, Dan Wu, Meng Yuan, Chao Yu, Jian Zhang, Chuannan Li, Yu Duan
Summary: CsPbX3 perovskite thin films fabricated by vacuum evaporation require precise optical constants for designing optical devices. Research shows that the three-oscillator model accurately describes the optical constants of CsPbBr3, and time-resolved photoluminescence can accurately predict the electric field intensity distribution and cavity length.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Instruments & Instrumentation
Steffen Richter, Mateusz Rebarz, Oliver Herrfurth, Shirly Espinoza, Ruediger Schmidt-Grund, Jakob Andreasson
Summary: The study introduces a setup for time-resolved spectroscopic ellipsometry using femtosecond laser pulses, achieving measurements of transient ellipsometric parameters across various spectral ranges with high temporal resolution. Critical aspects such as probe pulse fluctuations and imperfections in polarization optics are analyzed and strategies for addressing related issues are presented.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Chemistry, Analytical
Samet Sahin, Zafer Ustundag, Mustafa Oguzhan Caglayan
Summary: In this study, a spectroscopic ellipsometry platform using aptamers was proposed for the detection of the endocrine-disrupting chemical Bisphenol A (BPA). The platform showed sensitive and selective detection of BPA, with a detection limit of 215 pM and 36 pM for two different BPA-specific aptamers. The sensor also exhibited good specificity and analytical performance.
Article
Chemistry, Analytical
Adeem Alshammari, Harm van Zalinge, Ian Sandall
Summary: The dissolution behavior of zinc oxide is investigated using spectroscopic ellipsometry to assess its suitability as a biosensing platform. The results show that functionalized zinc oxide surfaces are well-protected and do not dissolve significantly. The binding kinetics of the SARS-CoV-2 spike protein on aptamer-functionalized zinc oxide surfaces are studied, revealing fluctuation in surface density upon initial exposure and a stable increase in density with increasing protein concentration. The technique and setup demonstrate a limit-of-detection of 1 nanomole (nM) and a linear response up to 100 nM.
Article
Chemistry, Physical
Runtian Qie, Saeed Zajforoushan Moghaddam, Esben Thormann
Summary: This study demonstrates the importance of considering the optical properties of polydopamine coatings in ellipsometry analysis. By systematically varying the film thickness and surface roughness, it is shown that different oxidation conditions can lead to polydopamine coatings with varying structural and optical properties, requiring unique optical models for accurate estimation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
M. Isik, S. Delice, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: In this study, the structural properties of Bi12TiO20 single crystal grown by Czochralski method were investigated using X-ray diffraction and scanning electron microscope techniques. The research found that the crystal surface was almost uniform and smooth, with a cubic crystalline structure. Thermally stimulated current experiments revealed the presence of two hole centers in the crystal.
Article
Chemistry, Multidisciplinary
Yixuan Dou, Marie Solange Tumusange, Jianbo Jin, Xiaoming Wang, Erin R. Crater, Suhao Liu, Liyan Zhu, Samir Zuberi, Gavin Harman, Conner Weaver, Balaji Ramanujam, Ambalanath Shan, Robert B. Moore, Nikolas J. Podraza, Yanfa Yan, Lina Quan
Summary: This paper reports the discovery of a broadband (540-1060nm) achromatic quarter waveplate (A-QWP) based on a two-dimensional (2D) layered hybrid copper halide (HCH) perovskite single crystal. The A-QWP can modulate light polarization and retardation across a broad range of wavelengths. The design of the A-QWP utilizes the in-plane optical birefringence triggered by Jahn-Teller distortion in the 2D copper chloride (CuCl6) layers of the HCH crystal.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Optics
J. Skriniarova, P. Hronec, J. Chlpik, A. Laurencikova, J. Kovac Jr, J. Novak, R. Andok
Summary: This paper focused on investigating the GaP volume fraction in GaP nanowires prepared on GaP substrates by MOVPE using VLS mode. Spectroscopic ellipsometry and scanning electron microscopy image processing methods were used, showing a good agreement. The volume fraction of GaP on the top of the nanowires ranged from 1.5% to 6.3%, while at the bottom it was between 34.8% and 39.6%.
Article
Materials Science, Multidisciplinary
M. Terlemezoglu, O. Surucu, M. Isik, N. M. Gasanly, M. Parlak
Summary: Nickel oxide thin films were deposited using the radio frequency magnetron sputtering technique. The structural and morphological properties of the films were analyzed using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray analysis. The films were found to have a cubic phase of nickel oxide with a preferential orientation of (200) direction, and the surface morphology was observed to be uniform and smooth. Optical properties of the films were studied using Raman spectroscopy and temperature-dependent transmittance spectroscopy, and the band gap energy of the films was obtained using Tauc relation and derivative spectroscopy techniques. Furthermore, the relationship between the band gap energy and temperature was investigated using the Varshni optical model, and the absolute zero band gap energy, rate of change of band gap energy, and Debye temperature were determined as 3.57 eV, - 2.77 x 10(-4) eV/K, and 393 K, respectively.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Optics
Yasemin Pepe, Mehmet Isik, Ahmet Karatay, Elif Akhuseyin Yildiz, Nizami Gasanly, Ayhan Elmali
Summary: This work reports the defect and input intensity dependent nonlinear optical behaviors of Bi12GeO20 (BGO) single crystal. The study reveals the mechanisms contributing to both saturable absorption (SA) and nonlinear absorption (NA), and determines the saturation intensity threshold and effective nonlinear absorption coefficients. The findings suggest that the spectral range for saturable absorption and nonlinear absorption can be broadened by overlapping defect states in the energy band gaps.
JOURNAL OF LUMINESCENCE
(2022)
Article
Engineering, Electrical & Electronic
S. Delice, M. Isik, N. M. Gasanly
Summary: In this paper, the linear and nonlinear optical properties of lead molybdate (PbMoO4) single crystals were studied. The results showed that the material may be used in UV filter and sensor applications.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2022)
Article
Materials Science, Multidisciplinary
S. Delice, M. Isik, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: Optical characterization of PbWO4 single crystals grown by the Czochralski method was performed using spectroscopic ellipsometry experiments. The tetragonal scheelite structure and the energy dependence of the complex dielectric function of the crystal were determined. The refractive index, dielectric constant, and optical band gap were calculated, and two critical points in the dielectric function were identified.
Article
Materials Science, Multidisciplinary
O. Surucu, M. Isik, M. Terlemezoglu, T. Bektas, N. M. Gasanly, M. Parlak
Summary: CuSbSe2 thin film was prepared by co-evaporation, and its structural, morphological, and optical properties were investigated. The film exhibited an orthorhombic crystalline structure with a nearly uniform surface. The optical analysis showed a small band gap energy and a room temperature direct band gap.
Article
Optics
Yasemin Pepe, Mehmet Isik, Ahmet Karatay, Nizami Gasanly, Ayhan Elmali
Summary: This study reports the influence of excitation wavelength and input intensity on the nonlinear absorption mechanism and optical limiting behavior of the Bi12TiO20 (BTO) single crystal. The results show that the BTO single crystal has nonlinear absorption ability and the absorption coefficient varies with the excitation wavelength and input intensity.
JOURNAL OF LUMINESCENCE
(2023)
Article
Materials Science, Multidisciplinary
M. Isik, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: This paper reports the structural and optical properties of PbMo0.75W0.25O4 single crystals grown by Czochralski method. The crystal exhibited well-defined diffraction peaks and a tetragonal crystalline structure. Raman and infrared spectra were used to study the vibrational characteristics, with Raman modes associated with PbMoO4 and PbWO4 and eight bands observed in the infrared spectrum. The transmission spectrum revealed a direct band gap energy of 3.12 +/- 0.03 eV and a linear behavior of composition-band gap energy for PbMo1-xWxO4 compounds.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
M. Isik, N. M. Gasanly
Summary: This paper investigates the linear and nonlinear optical properties of Bi12GeO20 single crystals grown by the Czochralski method. Transmission and reflection measurements were carried out in the 400-1000 nm range, and the obtained spectra were analyzed using well-known optical models. The spectral dependencies of the absorption coefficient, refractive index, and dielectric function were presented. The results also include the analysis of the absorption coefficient and the determination of the nonlinear susceptibilities and refractive index of the crystal.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Physics, Multidisciplinary
M. Isik, I Guler, N. M. Gasanly
Summary: The structural and optical properties of the double sodium-bismuth molybdate NaBi(MoO4)(2) semiconductor compound were investigated using X-ray diffraction, Raman, and transmission experiments. The crystal exhibited a tetragonal structure according to the X-ray diffraction results. The vibrational modes of the crystal were identified through Raman experiments. Transmission experiments were conducted in the temperature range of 10-300 K. Derivative spectroscopy and absorption spectrum analysis showed consistent results regarding the change in band gap energy of the crystal with temperature. The absorption spectrum obtained from transmission measurements at varying temperatures revealed the absolute zero value of the band gap energy as 3.03 +/- 0.02 eV, the average phonon energy as Eph = 24 +/- 0.2 meV, and the Urbach energy of the crystal as 0.10 eV.
Article
Engineering, Electrical & Electronic
M. Isik, I. Guler, N. M. Gasanly
Summary: The structural and optical characteristics of NaBi(Mo0.5W0.5O4)2 single crystals grown by Czochralski method were investigated. The compound exhibited a tetragonal crystalline structure with a space group I41/a. The vibrational properties of the compound were studied using Raman and infrared transmittance spectra. The reported characteristics of NaBi(Mo0.5W0.5O4)2 suggest that it has significant potential for use in optoelectronic devices.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Anil Dogan, Ahmet Karatay, Mehmet Isik, Yasemin Pepe, Nizami Gasanly, Ayhan Elmali
Summary: Nonlinear absorption mechanisms, excitation wavelength dependence, and defect states of Bi12SiO20 (BSO) single crystal were investigated. The NA behavior decreased with increasing pump intensity as the defect states at around 2.32 eV by one photon absorption (OPA) at 532 nm and two photon absorption (TPA) at 1064 nm excitations. The dominant NA mechanisms are OPA and sequential TPA at 532 nm as compared to the 1064 nm. A higher NA coefficient was obtained at 532 nm as compared to 1064 nm excitation, attributed to higher contribution of OPA at 532 nm even at lower input intensities compared to TPA contribution at 1064 nm. Onset optical limiting thresholds were found as 0.34 and 0.68 mJ/cm2 for 532 and 1064 nm input beams, respectively. The BSO single crystal may be used as a saturable absorber or an optical limiter at convenient input intensity by effectively adjusting defect states and excitation wavelength.
Article
Nanoscience & Nanotechnology
M. Isik, S. Delice, N. M. Gasanly
Summary: The present study reported the structural and temperature-dependent band gap characteristics of CeO2 nanoparticles on a glass substrate. XRD analysis showed a face-centered cubic structure with nine related peaks. SEM images indicated that CeO2 existed in the form of nanoparticles with a diameter ranging from 20 to 30 nm. Transmission measurements showed a decrease in the direct band gap energy from 3.35 to 3.29 eV as the sample temperature increased from 10 K to room temperature. The temperature dependence of the band gap energy was analyzed using the Varshni expression, revealing an absolute zero band gap energy of 3.35 eV and a rate of change of -4.7x10-4 eV/K.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
M. Isik, O. Surucu, N. M. Gasanly
Summary: GaSe0.75S0.25, as a potential semiconductor compound, shows hexagonal structure and has a band energy of 2.34 eV. The GaSe0.75S0.25 thin film grown on a glass substrate was also successfully obtained on a silicon wafer, forming a p-GaSe0.75S0.25/n-Si heterojunction. Temperature-dependent current-voltage (I-V) measurements were conducted to characterize the electrical properties of the heterojunction, revealing a decrease in the ideality factor and an increase in the barrier height with increasing temperature. The conduction mechanism was investigated considering the Gaussian distribution of barrier height inhomogeneity.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Materials Science, Ceramics
S. Delice, M. Isik, N. M. Gasanly, N. H. Darvishov, V. E. Bagiev
Summary: LiGd(MoO4)2 crystal was investigated for its structural and temperature dependent optical properties, showing potential for optoelectronic applications and development of light-emitting diodes. The crystal exhibited a single phase tetragonal structure with six distinguishable peaks corresponding to vibrational modes of (MoO4)2 tetrahedron. Infrared transmittance spectrum indicated multiphonon absorptions, and the temperature dependent transmittance curves were used to determine the band gap and its temperature dependence. Room temperature photoluminescence spectrum demonstrated red light emission, making LiGd(MoO4)2 a potential candidate for optoelectronic devices emitting red light.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Condensed Matter
M. Isik, I. Guler, N. Gasanly
Summary: In this study, the linear and nonlinear optical properties of layered single crystals of Tl2In2S3Se were investigated using ellipsometry measurements. Various optical parameters were determined through analysis.
PHYSICA B-CONDENSED MATTER
(2023)
