Band gap energy of chalcopyrite thin film solar cell absorbers determined by soft x-ray emission and absorption spectroscopy

Different amounts of Fe, Co, Ni and Cu-doped TiO2 thin films were prepared on fluorine doped tin oxide (FTO) coated soda-lime glass substrates by following a conventional sol-gel dip-coating technique followed by heat treatment at 550 and 600°C for 30 min. These thin films were characterized for photo-current, chronoamperometry and band-gap energy values. The chemical compositions of metals-doped TiO2 thin films on FTO glass substrates were confirmed by XPS spectroscopic study. The metal-ions doped TiO2 thin films had a thickness of <200 nm="" optical="" transparency="" of="">80%, band-gap energy of >3.6 eV, and a direct band-to-band energy transition. The photoelectrochemical (PEC) studies revealed that all the metal-ions doped TiO2 thin films exhibit n-type semi-conducting behavior with a quite stable chronoamperometry and photo-currents that increase with the increase of applied voltage but decrease with the dopant metal-ion concentration in the thin film. Furthermore, these thin films exhibited flat-band potentials amenable to water oxidation reaction in a PEC cell. The 0.5 wt.% Cu-doped TiO2 thin film electrode exhibited an highest incident photon-to-current conversion efficiency (IPCE) of about 21%.

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Effect of ZnO on a Superhydrophilic Self-Cleaning Properties of TiO2/SiO2 Thin Film on Glass Slide Substrate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1131.237 ◽

2015 ◽

Vol 1131 ◽

pp. 237-241 ◽

Cited By ~ 1

Author(s):

Akkarat Wongkaew ◽

Chanida Soontornkallapaki ◽

Naritsara Amhae ◽

Wichet Lamai

Keyword(s):

Thin Film ◽

Contact Angle ◽

Visible Light ◽

Band Gap ◽

Sol Gel ◽

Dip Coating ◽

Band Gap Energy ◽

Gap Energy ◽

Coating Method ◽

Dip Coating Method

This work aims to study the effect of ZnO containing in TiO2/SiO2 film on the superhydrophilic property after exposed to different types of light. The metal solutions were prepared by sol-gel technique and the film was deposited on glass slides by dip coating method. The parameter studied was the amount of ZnO in the TiO2/SiO2 film. The contents of ZnO were 5-20% weight (increased by 5%). The amount of TiO2 was constant at 30% weight. The obtained films were analyzed for their roughness. The results indicated that film roughness changed according to the ZnO contents. With 5%ZnO in the thin film, the roughness was 0.726 nm while 20%ZnO obtained the roughness of 2.128 nm. UV-Vis spectrophotometer was used for measuring of transmittance of films. At wavelength of 550 nm, the transmittances of each film were greater than 90%. Band gap energy of each film was calculated from the transmittance data. It was found that the average band gap energy of the films was 2.47 eV. Then, the films contained various amount of ZnO were grouped into 2 sets. The first set was exposed to visible light while the other set was exposed to UV. The duration of exposure was 5 hr. Both sets of films after exposed to any light were kept in a black box controlled relative humidity of 85%. Each film was measured contact angle every day. It was found that the 30%TiO2/5%Zn/SiO2 film exposed to visible light showed the best superhydrophilic property. The contact angle was about 0-5° within 3 days. This may due to the reduction of band gap energy in the presence of ZnO in TiO2/SiO2 films to 2.41 eV and the roughness of the film.

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A correlation for crystallite size of undoped ZnO thin film with the band gap energy – precursor molarity – substrate temperature

Optik ◽

10.1016/j.ijleo.2013.08.015 ◽

2014 ◽

Vol 125 (3) ◽

pp. 1303-1306 ◽

Cited By ~ 23

Author(s):

Said Benramache ◽

Okba Belahssen ◽

Ali Arif ◽

Abderrazak Guettaf

Keyword(s):

Thin Film ◽

Substrate Temperature ◽

Band Gap ◽

Crystallite Size ◽

Band Gap Energy ◽

Zno Thin Film ◽

Gap Energy

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Prediction and optimization of the performance characteristics of CZTS thin film solar cell using band gap grading

Optical and Quantum Electronics ◽

10.1007/s11082-017-1176-3 ◽

2017 ◽

Vol 49 (10) ◽

Cited By ~ 13

Author(s):

Adeyinka D. Adewoyin ◽

Muteeu A. Olopade ◽

Michael Chendo

Keyword(s):

Thin Film ◽

Solar Cell ◽

Band Gap ◽

Thin Film Solar Cell ◽

Performance Characteristics ◽

Czts Thin Film

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Study on Band Gap Energy of F Doped TiO2 Nanotubes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.889.234 ◽

2017 ◽

Vol 889 ◽

pp. 234-238

Author(s):

Mohd Hasmizam Razali ◽

Nur Arifah Ismail ◽

Mahani Yusoff

Keyword(s):

Band Gap ◽

Diffuse Reflectance Spectroscopy ◽

Small Diameter ◽

Ultra Violet ◽

Band Gap Energy ◽

X Ray Diffraction ◽

X Ray ◽

Gap Energy ◽

Transmission Electron ◽

Xrd Patterns

Pure and F doped TiO2 nanotubes was synthesized using simple hydrothermal method. The hydrothermal was conducted using teflon-liner autoclave and maintained at 150oC for 24 hours. The characterization of synthesised product was carried out using x-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive of x-ray spectroscopy (EDX) and ultra violet – visible light diffuse reflectance spectroscopy (UV-Vis DRS) for band gap measurements. XRD patterns indicated that anatase TiO2 phase was remained after F doping suggested that fluorine was highly dispersed into TiO2 by substituted with O in the TiO2 lattice to formed TiO2-xFx solid solution. Morphology investigation using TEM found out small diameter of nanotubes structure within 8 – 10 nm of pure and F doped TiO2 nanotubes. The band gap energy (Eg) of both nanotubes samples were almost similar proposing that F doping does not modify the band gap energy.

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