X- ray diffraction and dielectric properties of PbSe thin films

2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Peijie Lin ◽  
Sile Lin ◽  
Shuying Cheng ◽  
Jing Ma ◽  
Yunfeng Lai ◽  
...  

Ag-doped In2S3(In2S3:Ag) thin films have been deposited onto glass substrates by a thermal evaporation method. Ag concentration is varied from 0 at.% to 4.78 at.%. The structural, optical, and electrical properties are characterized using X-ray diffraction (XRD), spectrophotometer, and Hall measurement system, respectively. The XRD analysis confirms the existence of In2S3and AgIn5S8phases. With the increase of the Ag concentration, the band gap of the films is decreased gradually from 2.82 eV to 2.69 eV and the resistivity drastically is decreased from ~103to5.478×10-2 Ω·cm.


2019 ◽  
Vol 17 (41) ◽  
pp. 15-28
Author(s):  
Hussain. M. Selman

BixSb2-xTe3 alloys with different ratios of Bi (x=0, 0.1, 0.3, 0.5, and 2) have been prepared, Thin films of these alloys were prepared using thermal evaporation method under vacuum of 10-5 Torr on glass substrates at room temperature with different deposition rate (0.16, 0.5, 0.83) nm/sec for thickness (100, 300, 500) respectively. The X–ray diffraction measurements for BixSb2-xTe3 bulk and thin films indicate the polycrystalline structure with a strong intensity of peak of plane (015) preferred orientation with additional peaks, (0015) and (1010 ) reflections planes, which is meaning that all films present a very good texture along the (015) plane axis at different intensities for each thin film for different thickness. AFM measurements for the thin films of BixSb2-xTe3, show that the grain size and the average surface roughness decreases with increasing of the percentage Bi for different thickness.


2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
M. F. A. Alias ◽  
A. A. J. Al-Douri ◽  
E. M. N. Al-Fawadi ◽  
A. A. Alnajjar

Results of a study of alloys and films with various Pb content have been reported and discussed. Films of of thickness 1.5 μm have been deposited on glass substrates by flash thermal evaporation method at room temperature, under vacuum at constant deposition rate. These films were annealed under vacuum around 10−6Torr at different temperatures up to 523 K. The composition of the elements in alloys was determined by standard surfaces techniques such as atomic absorption spectroscopy (AAS) and X-ray fluorescence (XRF), and the results were found of high accuracy and in very good agreement with the theoretical values. The structure for alloys and films is determined by using X-ray diffraction. This measurement reveals that the structure is polycrystalline with cubic structure and there are strong peaks at the direction (200) and (111). The effect of heat treatment on the crystalline orientation, relative intensity, and grain size of films is presented.


2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Swati Arora ◽  
Vivek Jaimini ◽  
Subodh Srivastava ◽  
Y. K. Vijay

Bismuth telluride has high thermoelectric performance at room temperature; in present work, various nanostructure thin films of bismuth telluride were fabricated on silicon substrates at room temperature using thermal evaporation method. Tellurium (Te) and bismuth (Bi) were deposited on silicon substrate in different ratio of thickness. These films were annealed at 50°C and 100°C. After heat treatment, the thin films attained the semiconductor nature. Samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) to show granular growth.


2013 ◽  
Vol 678 ◽  
pp. 123-130 ◽  
Author(s):  
K. Kandaswamy ◽  
Panneerselvam Chirstopher Selvin ◽  
B. Nalini ◽  
I. Mohamed Abdulla ◽  
K.P. Abhilash

Thin films of Bi1.5(Sb2S3)0.5of different thickness were deposited on glass substrate by vacuum thermal evaporation method and annealed at different temperature. The elemental compositions of the films were confirmed by energy dispersive X-ray analysis (EDAX). The prepared films were structurally and morphologically characterized by X-ray diffraction (XRD) and microscopic (SEM & AFM) techniques respectively. It has been confirmed that the films possess polycrystalline nature with orthorhombic phase and the grain size of the films vary from 27.92 to 81.37 nm. The observed bandgap energies (varying from 1.787eV to 1.963 eV) of the films and its temperature dependence were estimated from optical absorption measurements.


2015 ◽  
Vol 772 ◽  
pp. 62-66 ◽  
Author(s):  
R. Steigmann ◽  
N. Iftimie ◽  
A. Savin

Zinc oxide nanostructured materials, such as films and nanoparticles, could provide a suitable platform for development of high performance biosensing material due to their unique fundamental material properties. This paper presents the characterization of ZnO thin film as biosensing material by metallic strip grating structure (MSG), for the real-time detection. In this work, high quality ZnO films were grown on ITO/glass substrates by vacuum thermal evaporation method. We characterized by X-ray diffraction (XRD) the film crystalline quality and by scanning electron microscopy (SEM) the film morphology.


2005 ◽  
Vol 871 ◽  
Author(s):  
Cristobal Voz ◽  
Joaquim Puigdollers ◽  
Marta Fonrodona ◽  
Isidro Martin ◽  
Albert Orpell ◽  
...  

AbstractThe microstructure of pentacene thin films deposited by thermal evaporation is studied by X-ray diffraction. The transmittance of these films evidences different molecular orbital levels and their related excitonic states. Pentacene photodiodes have been also fabricated on ITO-coated glass substrates with aluminium top electrodes. The current voltage characteristics of such devices are discussed paying special attention to the strongly marked space-charge limited regime. This has been related to trapping in an exponential distribution of localised states in the gap of pentacene. The analysis of the characteristic offers valuable information about such distribution of traps. Finally, the external-quantum-efficiency of these photodiodes shows antibatic features, which evidence the importance of excitonic states in the photovoltaic conversion in pentacene.


Author(s):  
T.C.M. Santhosh ◽  
Kasturi V. Bangera ◽  
G.K. Shivakumar

It has been a general practice to dope thin films with suitable dopants to modify the properties of the films to make them more suitable for potential applications. When the dopant concentrations are low, they do not normally affect the structure and morphology of the films. However, it may lead to drastic changes in electronic properties of the films. This might result from the dopant getting incorporated into the lattice of the material of the films. Cadmium selenide is an important compound semiconductor material with an attractive energy band gap. The present work relates to an attempt made to dope CdSe thin films with silver. CdSe : Ag (1 to 5%) thin films were deposited on glass substrates at an optimized substrate temperature of 453 K using thermal evaporation technique. The grown films were analyzed using X-ray diffraction, scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) techniques. It is observed that undoped CdSe thin films and CdSe : Ag films have hexagonal structure. The grain size was found to increase marginally with an increase in the Ag concentration. The optical band gap of the films determined by optical transmission measurements agree with that of CdSe. Electrical conductivity is observed to increase from 10-4 to 3.66 (Omega ·cm)-1 on addition of silver. The variation of resistance with temperature indicates that the prepared films consist of CdSe and Ag existing as two separate phases coexisting and contributing individually to the resistivity of the films. DOI: 10.21883/FTP.2017.12.45181.8430


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Wei Chen

Thermoelectric (TE) materials are crucial because they can be used in power generation and cooling devices. Sb2Te3-based compounds are the most favorable TE materials because of their excellent figure of merit at room temperature. In this study, Sb2Te3thin films were prepared on SiO2/Si substrates through thermal evaporation. The influence of the evaporation current on the microstructures and TE properties of Sb2Te3thin films were investigated. The crystalline structures and morphologies of the thin films were analyzed using X-ray diffraction and field emission scanning electron microscopy. The Seebeck coefficient, electrical conductivity, and power factor (PF) were measured at room temperature. The experimental results showed that the Seebeck coefficient increased and conductivity decreased with increasing evaporation current. The Seebeck coefficient reached a maximum of 387.58 μV/K at an evaporation current of 80 A. Conversely, a PF of 3.57 µW/cmK2was obtained at room temperature with evaporation current of 60 A.


Author(s):  
M. Musaab Khudhr ◽  
Khalid Haneen Abass

Aluminum doped ZnO (AZO) thin films doped has been prepared by thermal evaporation method onto glass substrates. The optical characterization has been studied by UV-Visible Spectrophotometer in the range (300-1100) nm. The transmittance increased with increasing Al-doping, while absorption decreases with increasing Al-doping content. The energy gap (Eg) values increased with increasing Al-doped in the ZnO:Al thin films. The refractive index, extinction coefficient, and real and imaginary dielectric constants obtained results show that doping content strongly affects the optical parameters of AZO thin films. Optical constants tend to decrease with increasing doping content.


Sign in / Sign up

Export Citation Format

Share Document