LITAO3 CHARACTERIZATION OF RUBIDIUM ON TEMPERATURE VARIATIONS

2018 ◽  
Vol 1 (02) ◽  
pp. 54-59
Author(s):  
Agus Ismangil ◽  
Teguh Puja Negara
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
Transmission Rate ◽  
Ferroelectric Material ◽  
Band Gap Energy ◽  
Ferroelectric Materials ◽  
Annealing Process ◽  
Optical Modulators ◽  
Gap Energy

One of the studies that recently attracted the attention of physicists is research on ferroelectric material because this material is very promising for the development of new generation devices in connection with the unique properties it has. Ferroelectric materials, especially those based on a mixture of lithium tantalite (LiTaO3), are expected to be applied to the infrared sensor. Lithium tantalate (LiTaO3) is a ferroelectric material that is unique in terms of pyroelectric and piezoelectric properties that are integrated with good mechanical and chemical stability. Therefore LiTaO3 is often used for several applications such as electro-optical modulators and pyroelectric detectors. LiTaO3 is a non-hygroscopic crystal, colorless, soluble in water, has a high transmission rate and does not easily damage its optical properties. LiTaO3 is a material that has a high dielectric constant and a high load storage capacity. This research has succeeded in determining the band gap energy of the LiTaO3 film in the rubidium chamber obtained in the range of values 2.02-2.98 eV as shown in figure 4. The LiTaO3 film after the annealing process at a temperature of 650 oC, has the highest band gap energy of 2.98 eV. Large energy is needed on the electrons to be excited from the valence band to the conduction band. Whereas in the LiTaO3 film after an annealing process of 800 oC, the band gap energy obtained is 2.02 eV. This makes it easier for electrons to be excited from the valence band to the conduction band because the energy needed is not too large.

scholarly journals The Effect of Niobium and Rubidium Doping on the Energy Band Gap of a Lithium Tantalate (LiTaO3) Thin Film

2021 ◽  
Vol 32 (2) ◽  
pp. 1-5
Author(s):  
Agus Ismangil ◽  
Fatimah Arofiati Noor ◽  
Toto Winata
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
Chemical Solution Deposition ◽  
Band Gap Energy ◽  
Chemical Solution ◽  
Energy Band Gap ◽  
Solution Deposition ◽  
Gap Energy ◽  
Niobium Doped

Chemical solution deposition (CSD) is a technique for making a film by keeping synthetic arrangements on the outer layer of the substrate. The outcomes show that the band gap energy of the LiTaO3 film is 1 eV. Electrons are more effectively invigorated to the valence band than to the conduction band on the grounds that the energy required is not excessively huge. Niobium-doped LiTaO3 film has a band gap energy of 1.15 eV. A large amount of energy is needed for electrons to be energized from the valence band to the conduction band. The rubidium-doped LiTaO3 film has a band gap energy of 1.30 eV.

Study of Band Alignment at CBD-CdS/Cu(In1-xGax)Se2 (x = 0.2 - 1.0) Interfaces by Photoemission and Inverse Photoemission Spectroscopy

2007 ◽  
Vol 1012 ◽  
Author(s):  
Shimpei Teshima ◽  
Hirotake Kashiwabara ◽  
Keimei Masamoto ◽  
Kazuya Kikunaga ◽  
Kazunori Takeshita ◽  
...  
Keyword(s):  
Band Gap ◽  
Conduction Band ◽  
Valence Band Maximum ◽  
Band Gap Energy ◽  
Band Alignment ◽  
Photoemission Spectroscopy ◽  
Gap Energy ◽  
Conduction Band Offset ◽  
Inverse Photoemission ◽  
Inverse Photoemission Spectroscopy

AbstractDependence of band alignments at interfaces between CdS by chemical bath deposition and Cu(In1-xGax)Se2 by conventional 3-stage co-evaporation on Ga substitution ratio x from 0.2 to 1.0 has been systematically studied by means of photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES). For the specimens of the In-rich CIGS, conduction band minimum (CBM) by CIGS was lower than that of CdS. Conduction band offset of them was positive about +0.3 ~ +0.4 eV. Almost flat conduction band alignment was realized at x = 0.4 ~ 0.5. On the other hand, at the interfaces over the Ga-rich CIGS, CBM of CIGS was higher than that of CdS, and CBO became negative. The present study reveals that the decrease of CBO with a rise of x presents over the wide rage of x, which results in the sign change of CBO around 0.4 ~ 0.45. In the Ga-rich interfaces, the minimum of band gap energy, which corresponded to energy spacing between CBM of CdS and valence band maximum of CIGS, was almost identical against the change of band gap energy of CIGS. Additionally, local accumulation of oxygen related impurities was observed at the Ga-rich samples, which might cause the local rise of band edges in central region of the interface.

Band gap energy and valence band splitting of p-CdIn2Te4 crystal by photocurrent spectroscopy

2004 ◽  
Vol 95 (8) ◽  
pp. 4042-4045 ◽  
Author(s):  
S. H. You ◽  
K. J. Hong ◽  
T. S. Jeong ◽  
C. J. Youn ◽  
J. S. Park ◽  
...  
Keyword(s):  
Band Gap ◽  
Valence Band ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Band Splitting ◽  
Photocurrent Spectroscopy ◽  
Valence Band Splitting

scholarly journals Valence Band Structure ofInAs1-xBixandInSb1-xBixAlloy Semiconductors Calculated Using Valence Band Anticrossing Model

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
D. P. Samajdar ◽  
S. Dhar
Keyword(s):  
Experimental Data ◽  
Band Gap ◽  
Valence Band ◽  
Band Gap Energy ◽  
Light Hole ◽  
Spin Orbit ◽  
Valence Band Structure ◽  
Gap Energy ◽  
Valence Band Anticrossing ◽  
Band Anticrossing

The valence band anticrossing model has been used to calculate the heavy/light hole and spin-orbit split-off energies inInAs1-xBixandInSb1-xBixalloy systems. It is found that both the heavy/light hole, and spin-orbit splitE+levels move upwards in energy with an increase in Bi content in the alloy, whereas the splitE−energy for the holes shows a reverse trend. The model is also used to calculate the reduction of band gap energy with an increase in Bi mole fraction. The calculated values of band gap variation agree well with the available experimental data.

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

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