Optical dynamics of MgO/Ga4Se3S interface

Qasrawi, A. F.
Abd-Alrazq, Mariam M.
Hasanlı, Nızamı
A new p-n interface made of p-type MgO as an optical window to the n-type Ga4Se3S crystals is investigated by means of optical reflectance, transmittance and absorbance in the incident light wavelength (k) range of 200-1100 nm. The reflectivity spectral analysis as a function of angle of incidence for MgO, Ga4Se3S and the Ga4Se3S/MgO layers revealed Brewster angles of 75 degrees, 80 degrees and 70 degrees with the corresponding dielectric constants of 13.93, 32.16 and eMgO 7: 55eGa(4)Se(3)S, respectively. To remove Brewster condition of reflection and obtain maximum absorption, the light must be incident from the MgO side. A novel light absorbability is observed. Namely, for all k < 600 nm, the absorbance is dominated by the Ga4Se3S layer. For larger k values, while the crystal absorbance decreases significantly, the bilayer absorbance increased by four times in the visible range and three times in the IR range of spectrum. In the MgO layer, two distinct sets of band tails of the localized states with the widths of 2.30 and 1.26 eV are determined from the absorption spectral analysis. These band tails shift up to 2.32 and 1.44 eV when the interface is constructed. In addition, an indirect energy band gaps (Eg) which are located at 3.10, 2.13 and 1.90 eV for the MgO, Ga4Se3S and the Ga4Se3S/MgO layers, respectively, are determined. The Eg value of the crystal shifts by a 0.23 eV upon bilayer construction. The reflection properties, the band tails, the energy gaps and related shifts make the Ga4Se3S/MgO interface attractive for fabrication of solar cells, narrow barrier resonant tunneling diodes or quantum dots, and as an optical detector for tunable types of lasers. (C) 2013 Published by Elsevier B.V.


Annealing improvement on the localized states of plasma grown boron nitride film assessed through admittance measurements
ÖZDEMİR, Orhan; Anutgan, Mustafa; Aliyeva-Anutgan, Tamila; Atilgan, Ismail; Katircioglu, Bayram (Elsevier BV, 2009-05-05)
Boron nitride (BN) thin film was grown by plasma enhanced chemical vapor deposition (PECVD) technique and was investigated by UV-Visible transmission, Fourier transform infrared (FTIR) and ac conductance spectroscopies. Mainly the density of electronic localized states (D-it) at BN/Si interface was obtained by continuum and statistical models of ac conductance through an MIS structure (Al/BN film/Si). The origins of the electronic defects have been outlined and discussed within the frame of a nitrogen defic...
Acoustic phonons scattering mobility and carrier effective mass in In6S7 crystals
Qasrawi, A. F.; Hasanlı, Nızamı (Elsevier BV, 2006-12-21)
Systematic dark electrical resistivity and Hall coefficient measurements have been carried out in the temperature range of 170-320 K on n-type In6S7 crystals. The analysis of the electrical resistivity and carrier concentration reveals the intrinsic type of conduction with an average energy band gap of similar to 0.75 eV The carrier effective masses of the conduction and valence bands were calculated from the intrinsic temperature-dependent carrier concentration data and were found to be 0.565m(0) and 2.020...
Local structure in marginal glass forming Al-Sm alloy
Kalay, Yunus Eren; Kramer, M. J.; Anderson, I. E. (Elsevier BV, 2010-08-01)
The local structure in rapidly quenched Al(100-x)Smx (x = 8, 10, 11, and 12) and liquid Al89Sm11 has been investigated using a combination of transmission electron microscopy (TEM) and high-energy synchrotron X-ray diffraction (HEXRD). TEM analysis showed a featureless microstructure with diffuse scattering in rapidly quenched Al(100-x)Smx (x = 8, 10, 11, and 12) within the glass formation composition range under the bright field (BF) conditions. Total structure factor analysis of the liquid and as-quenched...
Effects of annealing temperature on the structural and optical properties of ZnO hexagonal pyramids
BACAKSIZ, EMİN; YILMAZ, ŞERİFE; Parlak, Mehmet; Varilci, A.; Altunbas, M. (Elsevier BV, 2009-06-10)
ZnO thin films were deposited on quartz substrate at 550 degrees C by using spray pyrolysis method and subsequently annealed between 600-900 degrees C with a step of 100 degrees C. The characterizations of the structural and optical properties of the films have been carried out by means of X-ray diffraction, scanning electron microscopy (SEM) and optical transmittance measurements. XRD ans SEM images indicated that annealing temperature did not play a great role on the microstructure of ZnO films. ZnO thin ...
DOGAN, S; Akbulut, Ural; Toppare, Levent Kamil (Elsevier BV, 1992-11-01)
We describe an electrochemical synthesis of a conducting composite of polyaniline. Poly(bisphenol A carbonate) was used as the insulating polymer matrix. Composite characterization was made using FT-IR, SEM and DSC data. The conductivities of the composites seemed to be in the order of pure polyaniline as prepared by the same method. Moreover, the above-mentioned methods reveal that the resultant composites have different properties compared to a simple mechanical mixture of the two polymers.
Citation Formats
A. F. Qasrawi, M. M. Abd-Alrazq, and N. Hasanlı, “Optical dynamics of MgO/Ga4Se3S interface,” JOURNAL OF ALLOYS AND COMPOUNDS, pp. 180–185, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47078.