scholarly journals The effect of composition and substrate temperature on the optical energy gap of SiOx/SnO amorphous thin films

1990 ◽  
Vol 25 (6) ◽  
pp. 3002-3007 ◽  
Author(s):  
G. A. Khan ◽  
C. A. Hogarth
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Energy Gap ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Amorphous Thin Films

Optical properties of Se–Te–Sb thin films

2014 ◽  
Vol 92 (4) ◽  
pp. 328-334 ◽  
Author(s):  
O. El-Shazly ◽  
H.M. Khalifa ◽  
A. Sweyllam ◽  
F.F. El-Sanabary ◽  
E.F. El-Wahidy
Keyword(s):  
Thin Films ◽  
Composition Dependence ◽  
Vapour Deposition ◽  
Energy Gap ◽  
Normal Incidence ◽  
Localized States ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Amorphous Thin Films ◽  
Quartz Substrates

Amorphous thin films of Se80Te(20–X)SbX (X = 0, 4, 8, and 10 at. %) were deposited onto clean quartz substrates by vapour deposition (thermal evaporation) under a vacuum of 10−5 Torr. The transmission spectra at normal incidence in the spectral range of 250–2500 nm were measured at room temperature. The optical energy gap Eg was found to be indirect. The value of Eg was found to decrease from 1.69 to 1.43 eV with increasing Sb content. The composition dependence of the optical energy gap is discussed in terms of the chemical bond approach. The band tail width of localized states Ee was found to increase from 0.0297 to 0.0551 eV with increasing Sb content.

scholarly journals The Effect of Substrate Temperature on the Band Transition, Cauchy Dispersion and Urbach Energy of Nanostructure CdO Thin Films

2015 ◽  
Vol 58 ◽  
pp. 83-89
Author(s):  
Muneer H. Jadduaa ◽  
Zainab Ali Harbi ◽  
Nadir F. Habubi
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Urbach Energy ◽  
Energy Gap ◽  
Chemical Spray Pyrolysis ◽  
Optical Parameters ◽  
Optical Energy Gap ◽  
Substrate Temperature Increase ◽  
Band Transition ◽  
Cdo Thin Films

Thin films of CdO were prepared by chemical spray pyrolysis (CSP) . The effect of different temperature substrate (300,350,400,450 and 500) °C on some optical parameters has been studied . The transmittance and the optical energy gap were increased from (2.503-2.589) eV ,on the contrary of the rest parameters such as refractive index , real and imaginary parts of dielectric constant and Urbach energy which they were decreased as the substrate temperature increase.

scholarly journals Effect of Pb percentage on optical parameters of PbxCd1-xSe thin films

2019 ◽  
Vol 14 (29) ◽  
pp. 1-7
Author(s):  
Farah Q. Kamil
Keyword(s):  
Thin Films ◽  
Thermal Evaporation ◽  
Energy Gap ◽  
Optical Measurements ◽  
Optical Parameters ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Glass Substrates

PbxCd1-xSe compound with different Pb percentage (i.e. X=0,0.025, 0.050, 0.075, and 0.1) were prepared successfully. Thin filmswere deposited by thermal evaporation on glass substrates at filmthickness (126) nm. The optical measurements indicated thatPbxCd1-xSe films have direct optical energy gap. The value of theenergy gap decreases with the increase of Pb content from 1.78 eV to1.49 eV.

scholarly journals Hydrogenated Nano-Crystalline Silicon Thin Films in SiO2 Matrix for Next Generation Solar Cells Using Glow Discharged Decomposition

2018 ◽  
Vol 8 (1) ◽  
pp. 25
Author(s):  
Moniruzzaman Syed ◽  
Cameron Hynes ◽  
Brittany Anderson ◽  
Temer S Ahmadi ◽  
Boon Tong Goh ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Energy Gap ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Strong Dependence ◽  
Blue Shift ◽  
Nanocrystalline Silicon ◽  
Optical Energy Gap ◽  
Substrate Temperatures

Hydrogenated Nanocrystalline Silicon (nc-Si:H) thin films using SiH4/H2 mixture by glow discharged decomposition were investigated on c-Si and glass substrates. The effects of substrate temperature on the Structural, Optical and Electrical properties of the films were investigated by X-ray diffraction, Raman scattering, FT/IR, Optical transmission and Atomic Force Microscopy (AFM). Substrate temperatures ([TSB]) of the films were changed from 100oC to 250oC. It has been revealed the strong dependence on the film’s properties with the substrate temperatures. XRD and Raman measurements were shown that the higher substrate temperature (250oC) exhibits the highest crystalline volume fraction ([ρ] = 95%) and the lowest crystalline size ([Ω] = 3.5 nm) as well, having the highest H-content and the lowest O-content. At 250oC, the lowest mobility and the highest resistivity were also found to be ~37.5 cm2/v.s and 7.35 Ω-cm. Refractive index and the optical energy gap (Eg) were estimated by 3.8 and 1.9 eV having the growth rate of 4.2 nm/min. At 250oC, it was resulted in a blue shift of the absorption edge having uniform grain distributions. Results indicate that in situ hydrogen cleaning effects is prominent and localized orderly high density Si-Si bonds are exhibiting quantum size effects at highest substrate temperature.

OPTICAL ABSORPTION IN AMORPHOUS THIN FILMS OF SnO2 DEPOSITED BY THERMAL EVAPORATION

2007 ◽  
Vol 21 (12) ◽  
pp. 2017-2032 ◽  
Author(s):  
M. ANWAR ◽  
S. A. SIDDIQI ◽  
I. M. GHAURI
Keyword(s):  
Thin Films ◽  
Optical Absorption ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Band Gap ◽  
Optical Band Gap ◽  
Fundamental Absorption Edge ◽  
Outward Diffusion ◽  
Optical Energy ◽  
Amorphous Thin Films

The fundamental absorption edge of SnO 2 amorphous thin films has been investigated. It has been observed that the optical energy gap decreases with the increase in film thickness, substrate temperature and post deposition annealing. The results are analysed by assuming optical absorption by non-direct transition. The decrease in optical band gap with increase in film thickness may be interpreted in terms of the incorporation of oxygen vacancies in the SnO 2 lattice. The decrease in optical energy due to the increase in substrate temperature may be ascribed to the release of trapped electrons by thermal energy or by the outward diffusion of the oxygen-ion vacancies, which are quite mobile even at low temperatures. The decrease in optical band gap due to annealing may be due to the formation of tin species of lower oxidation state.

Composition dependence of the optical energy gap in Pb1−xHgxTe alloy thin films

1984 ◽  
Vol 82 (2) ◽  
pp. K181-K184 ◽  
Author(s):  
Mukesh Jain ◽  
A. V. R. Warrier ◽  
H. K. Sehgal
Keyword(s):  
Thin Films ◽  
Composition Dependence ◽  
Energy Gap ◽  
Optical Energy Gap ◽  
Optical Energy

scholarly journals Influence of Doping on Optical Properties of (CdS:Fe+3)Thin Films Prepared by Chemical Spray pyrolysis

2019 ◽  
Vol 30 (1) ◽  
pp. 193
Author(s):  
Karrar Mahdi Saleh
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spray Pyrolysis ◽  
Energy Gap ◽  
Nitrate Solution ◽  
Constant Thickness ◽  
Chemical Spray Pyrolysis ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Chemical Spray

In the present work, undoped CdS and doped with iron CdS:Fe+3 thin films have been prepared by chemical spray pyrolysis method on glass substrate with different temperature from cadmium nitrate solution with constant thickness(450 ± 5 nm), and study the effect of the percentage of doping with iron on optical properties of prepared films. The optical properties have been studied from transmittance and absorbance spectral within wavelengths range (380-900 nm). The results showed that all the prepared films has direct electronic transitions and optical energy gap between (2.31-2.44 eV). They also showed that the transmittance and optical energy gap of films prepared from nitrate solution increase with increasing of substrate temperature, then transmittance start downward with the continued increase in temperature (400, 450 oC), and a decrease in the optical energy gap with increasing doping percentage with iron.

scholarly journals Molar Concentration Effects on the Optical and Structural Properties of Nanostructural SnO2 Thin Films

2016 ◽  
Vol 65 ◽  
pp. 80-90 ◽  
Author(s):  
Nadir F. Habubi ◽  
Ziad M. Abood ◽  
Ahmed N. Algamel
Keyword(s):  
Thin Films ◽  
Energy Gap ◽  
Spray Pyrolysis Technique ◽  
Quantum Confinement Effect ◽  
Film Surface ◽  
Molar Concentration ◽  
Chemical Spray Pyrolysis ◽  
Concentration Effects ◽  
Optical Energy Gap ◽  
Optical Energy

Thin films of nanostructured SnO2 with different molariteswere prepared by chemical spray pyrolysis technique. XRD analysis reveals that all the films were tetragonal polycrystalline with a preferred orientation along (110) plane. AFM measurements indicate that the value of the grain size for 0.05 M, 0.1 M and 0.15 M were 111nm, 78 nm and 58 nm respectively. SEM micrograph proved the existence of small cracks on the film surface, EDS confirmed the composition percentage ratio of Sn and O­2 and no trace of impurities could be detected. PL spectra gives the indication about optical energy gap and the effect of concentration on it which appeared as a blue shift. The transmittance was studied for the deposited thin films, identifying that the transmittance decreases by the increase in molarity. The value of the optical energy gap of the deposited thin films was increased upon increasing molar concentration due o quantum confinement effect. The Urbach energy was also studied, their values decrease as the molar concentration increase.

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