scholarly journals The effect of doping variation on band gap energy and crystal structure of Biochar/TiO2 thin layer

2021 ◽  
Vol 1731 ◽  
pp. 012060
Author(s):  
H D Fahyuan ◽  
F Deswardani ◽  
N Nurhidayah ◽  
M F Afrianto ◽  
H Heriansyah ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thin Layer ◽  
Band Gap ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Effect Of Doping

Photoelectrochemical Properties of Alkali-treated Sodium Titanate Nanorods

2015 ◽  
Vol 1784 ◽  
Author(s):  
Mingu Kim ◽  
Gwanghyo Choi ◽  
Daeheung Yoo ◽  
Kwangmin Lee
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Band Gap ◽  
Heat Treatment Temperature ◽  
Alkali Treatment ◽  
Sodium Titanate ◽  
Band Gap Energy ◽  
Treatment Temperature ◽  
Photoelectrochemical Properties ◽  
Gap Energy

ABSTRACTThe band gap energy of the TiO2 photocatalytic is high at 3.2 eV. Ultraviolet (UV) light irradiation (<388nm) is required for the photocatalytic application. The lowering the band gap energy of TiO2 and enlarging light absorbing area are effective ways to enhance the efficiency of photocatalytic activity. Furthermore, the morphology and crystal structure of nanosized TiO2 considerably influences its photocatalytic behavior.In this study, sodium titanate nanorods were formed using an alkali-treatment and were heat treated at different temperatures. The photoelectrochemical properties of sodium titanate nanorods was measured as a function of heat treatment temperature. The nanorods were prepared on the surface of Ti disk with a diameter of 15mm and a thickness of 3mm. Ti disk was immersed in 5 M NaOH aqueous solution at a temperature of 60 °C for 24 h. Morphology of sodium titanate nanorods was observed using FE-SEM. Crystal structure of sodium titanate nanorods was analyzed using X-ray diffractometer. Photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) was used to evaluate photoelectrochemical properties of sodium titanate nanorods. The thin amorphous sodium titanate layer was formed during alkali-treatment. The sodium titanate layer was changed to nanorods after heat treatment at a temperature of 700 °C. The thickness and length of sodium titanate nanorods obtained at 700 °C were around 100 nm and 1μm, respectively. The crystal structure of sodium titanate was identified with Na2Ti6O13. Above 900 °C, the morphology of nanorods changed to agglomerated shape and the thickness of nanorods increased to 1 μm. The lowest value of PL was obtained at a temperature of 700 °C, while nonalkali treated specimen showed the highest value of PL. EIS revealed that polarization resistance at interface between sodium titanate nanorods and electrolyte was increased with increasing heat treatment temperature.

Effect of Nb doping on morphology, crystal structure, optical band gap energy of TiO2 thin films

2014 ◽  
Vol 14 (3) ◽  
pp. 421-427 ◽  
Author(s):  
Deuk Yong Lee ◽  
Ju-Hyun Park ◽  
Young-Hun Kim ◽  
Myung-Hyun Lee ◽  
Nam-Ihn Cho
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Tio2 Thin Films ◽  
Gap Energy ◽  
Nb Doping

Effect of 2,4-dinitrophenol dye doping on tristhioureazinc(II) sulfate single crystals: a potential nonlinear optical material

2020 ◽  
Vol 53 (4) ◽  
pp. 972-981 ◽  
Author(s):  
G. Durgababu ◽  
G. J. Nagaraju ◽  
G. Bhagavannarayana
Keyword(s):  
Crystal Structure ◽  
Band Gap ◽  
Single Crystals ◽  
Nonlinear Optical ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Optical Range ◽  
Gap Energy ◽  
Uv Visible ◽  
Crystalline Matrix

Good quality single crystals of 2,4-dinitrophenol (DNP)-doped tristhioureazinc(II) sulfate (ZTS) were successfully grown by employing the simple and cost effective slow-evaporation solution technique. To study the effect of doping on various device properties, the grown single crystals were subjected to powder X-ray diffraction (PXRD), high-resolution XRD, thermogravimetric analysis (TGA), Vickers hardness testing, and UV–visible, photoluminescence (PL) and Fourier transform IR (FTIR) spectroscopy techniques. The crystal structure of DNP-doped ZTS bulk single crystals remained the same as the crystal structure of ZTS. However, the changes in intensities of the diffraction peaks in the PXRD spectra indicated the incorporation of dopants into the crystalline matrix. FTIR studies confirm the incorporation of dopants into the crystalline matrix, shown by the shifting of certain prominent absorption bands towards higher energy. This also indicated the induced useful strain due to doping, leading to charge transfer and the enhancement of nonlinear optical properties. The cut-off wavelength and optical band gap energy of pure ZTS and DNP-doped ZTS crystals were studied by UV–visible absorption spectroscopy, revealing a slight reduction in the optical band gap energy due to doping, which in turn revealed the enhancement of the optical range. PL studies revealed an enhanced optical range of photoluminescence in ZTS crystals. Second harmonic generation (SGH) studies carried out by the Kurtz powder technique revealed the enhancement of SHG value due to DNP doping. To ensure the thermal stability and mechanical strength of the grown crystals with doping (required from the point of view of device applications), TGA and Vicker's hardness studies were performed.

Effects of L-Cysteine on the Photoluminescence Properties of ZnO:S Quantum Dots

2020 ◽  
Vol 842 ◽  
pp. 242-250
Author(s):  
Wen Dai ◽  
Shu Wang Duo ◽  
Xiao Xia Li ◽  
Zhong Chen ◽  
Zi Chuan Zheng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Quantum Dots ◽  
Band Gap ◽  
Visible Region ◽  
Average Crystallite Size ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Microwave Hydrothermal ◽  
Uv Emission ◽  
Zno Crystal

ZnO:S quantum dots (QDs) were synthesized by a microwave hydrothermal method. The effects of L-cysteine (L-cys) on the crystal structure, size, morphology, band gap energy and photoluminescence (PL) properties were studied by XRD, EDS, TEM, FTIR, DRS and PL spectroscopy, respectively. The XRD results showed that all samples had a wurtzite structure ZnO crystal structure and the average crystallite size was 8.4, 5.8, and 9.2 nm for ZnO, ZnO:S and L-cys capped ZnO:S (LZOS) QDs, respectively. The EDS, HRTEM and FTIR results confirmed L-cys was capped on the surface of ZnO:S QDs. It was found that the band gap energy was 3.25, 3.29 and 3.31 eV for ZnO, ZnO:S and LZOS QDs, successively. PL spectrum of ZnO QDs showed two emission peaks in the UV and visible region, respectively. When doping S into ZnO, the intensity of the UV emission reduced, while the intensity of the visible emission dramatically increased. Also, L-cys coated obviously enhanced the PL intensity of ZnO:S QDs. This work suggested that LZOS QDs could be applied in luminescent devices.

Band Gap Narrowing of MgO and Mg0.95Zn0.05O Nanostructures

2020 ◽  
Vol 307 ◽  
pp. 273-278
Author(s):  
Nor Fadilah Chayed ◽  
Nurhanna Badar ◽  
Kelimah Elong ◽  
Norlida Kamarulzaman
Keyword(s):  
Band Gap ◽  
Crystallite Size ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
Band Gap Energy ◽  
Synthesis Condition ◽  
Gap Energy ◽  
Band Gap Narrowing ◽  
Effect Of Doping

Preparation of MgO and Mg0.95Zn0.05O nanomaterials using self-propagating combustion method are done to investigate the effect of doping on the band gap energy. The synthesis condition has been optimized to obtain pure MgO and Mg0.95Zn0.05O materials which confirmed by XRD. FESEM results shows agglomeration of crystallite with average crystallite size of samples between 30 nm to 125 nm. The band gap obtained from the measurement of UV-Vis NIR spectrophotometer for MgO nanostructure is 6.36 eV which is lower than bulk MgO of 7.8 eV. The presence of Zn in Mg0.95Zn0.05O sample causes the narrowing of band gap to 5.33 eV.

The Influence of Nitrogen Doping Concentration on the Strain and Band Gap Energy of N-Doped Zinc Oxide Prepared Using Spray Coating Technique

2017 ◽  
Vol 266 ◽  
pp. 141-147 ◽  
Author(s):  
Heri Sutanto ◽  
Eko Hidayanto ◽  
Muhammad Irwanto ◽  
Mukholit ◽  
Singgih Wibowo ◽  
...  
Keyword(s):  
Thin Layer ◽  
Band Gap ◽  
Nitrogen Doping ◽  
Spray Coating ◽  
Band Gap Energy ◽  
Diffraction Field ◽  
Test Results ◽  
Gap Energy ◽  
Coating Technique ◽  
Diffraction Angle

N-ZnO thin layer is widely used in application of wastewater photo catalyst. N-ZnO thin films have been successfully deposited on glass substrate using spray coating technique at 450 °C with varying concentrations of N from Urea source. XRD test results showed that the N-ZnO has a polycrystalline structure with diffraction field (100), (002), (101) and (110). The presence of nitrogen atoms in the lattice of ZnO causes a shift in diffraction angle between 0.08o - 0.18o. N-ZnO thin layer showed the occurrence of tensile strain. Surface morphology of N-ZnO is shaped like mine (like root). All samples have band gap energies lower than that of ZnO and the smallest is sample N6 with Eg = 3.249 eV. The presence of nitrogen atom increases surface roughness and decreases band gap energy.

scholarly journals Synthesis of Binary Bi2S3/ZnO Nanorod Array Heterostructure and Their Photoelectrochemical Performance

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Asla A. AL-Zahrani ◽  
Zulkarnain Zainal ◽  
Zainal Abidin Talib ◽  
Hong Ngee Lim ◽  
Laimy Mohd Fudzi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Band Gap ◽  
Morphological Structure ◽  
Band Gap Energy ◽  
Photoelectrochemical Cell ◽  
Electron Hole ◽  
X Ray ◽  
Gap Energy ◽  
Zno Nras

One of the most effective strategies to improve the photoconversion efficiency in the photoelectrochemical cell is by using an assembly of heterostructures. To do so, a simple and inexpensive method, that is successive ionic layer adsorption and reaction (SILAR), is used to deposit the narrow band gap energy semiconductor Bi2S3 on ZnO nanorod arrays (NRAs) at different SILAR cycles. The obtained binary heterostructure thin films were characterized by using X-ray diffraction (XRD), UV-Vis Spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and linear sweep voltammogram (LSV) to prove the crystal structure, optical properties, band gap energy, morphological structure, composition of elements, and electrical properties. The XRD revealed that ZnO NRAs possessed a single wurtzite crystal structure while Bi2S3 possessed an orthorhombic crystal structure. The as-fabricated Bi2S3/ZnO heterostructure exhibited enhanced visible light absorption and charge separation efficiency of photoinduced electron-hole pairs. The band gap energy of binary heterostructure Bi2S3/ZnO NRAs is 3.11, 3.00, 2.33, 1.96, and 1.89 eV at 3, 5, 7, 9, and 11 SILAR cycles, respectively, confirming the substantial improvement of ZnO NRA optical properties. The highest photocurrent density has been achieved by 1.92 mA/cm2 of Bi2S3/ZnO NRAs fabricated at 7 cycles, exhibiting sixfold enhancement compared to that of intrinsic ZnO NRAs (0.336 mA/cm2). This impressive enhancement was ascribed to the significant improvement in morphological structure, crystallinity, and optical properties of heterostructure photoanodes. Significant improvement was achieved in the photoelectrochemical cell (PEC) performance attributed to the fast separation, low recombination rate, and low impedance of the photoinduced electron-hole pairs as shown throughout the electrochemical impedance spectra.

scholarly journals Synthesis and Characterization of SnO2 Thin Film Semiconductor for Electronic Device Applications

2021 ◽  
Vol 7 (SpecialIssue) ◽  
pp. 377-381
Author(s):  
Aris Doyan ◽  
Susilawati Susilawati ◽  
Kehkashan Alam ◽  
Lalu Muliyadi ◽  
Firdaus Ali ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thin Layer ◽  
Band Gap ◽  
Band Gap Energy ◽  
Synthesis And Characterization ◽  
Bandgap Energy ◽  
Gap Energy

Synthesis and characterization of SnO2 thin films with various types of doping materials such as aluminum, fluorine and indium have been successfully carried out. This study aims to determine the effect of various types of doping materials on the quality of thin films such as the energy band gap produced. The results showed that the higher the doping concentration, the more transparent the layer formed. In addition, the optical properties of thin films such as band gap energy are affected by the applied doping. The direct and indirect values ​​of the largest band gap energy for the percentage of 95:5% are 3.62 eV and 3.92 eV are found in the SnO2: In thin layer. Meanwhile, the lowest direct and indirect values ​​of band gap energy are in the thin layer of SnO2:(Al+F+In) for a percentage of 85:15%, namely 3.41 eV and 3.55 eV. The greater the amount of doping given, the smaller the bandgap energy produced. In addition, the more combinations of doping mixtures (aluminum, fluorine, and indium) given, the smaller the bandgap energy produced. This shows that the quality of a thin film of SnO2 produced is influenced by the amount of concentration and the type of doping used

Sign in / Sign up

Export Citation Format

Share Document