Synthesis and Characterization of Titanium (iv) Oxide Loaded with Silver Nano Particles Thin Films
Sunday Wilson Balogun,
Afolabi Bola Abdulhamid,
Yekini Kolawole Sanusi,
Adedokun Oluwaseun
Issue:
Volume 7, Issue 1, March 2019
Pages:
1-5
Received:
16 February 2019
Accepted:
26 March 2019
Published:
22 April 2019
Abstract: This research investigates effect of annealing temperature on the optical properties of titanium dioxide loaded with silver nanoparticles (TiO2: AgNPs) thin films deposited on glass substrate by spin–coating technique. Silver nanoparticles was prepared using laguminosae-paplionodeae extracts as a reducing agent for silver nitrate and commercially available titanium (iv) oxide was used. Deposition of TiO2:AgNPs blend solution was done in different volume ratio. The blend solution volume ratio of (1:0.2) was deposited at 7 different thicknesses with different speed of revolution per minutes (rpm) for 30 seconds. Annealing of 16 samples deposited at 1000 rpm on the glass substrate was carried out at temperature range of 50°C to 425°C with 10°C interval in a tubular furnance. It is observed from the results that the peak absorption of photon energy occurred at 375°C in the visible range of the wavelength spectrum. Optimal thickness for peak absorbance of the TiO2:AgNPs blend layer occurred at 115 nm in the visible spectrum and at the corresponding spin speed of 1000 rpm. Optimized fabrication process with blend layer thickness of 115 nm yielded the best absorbance at annealed temperature of 375°C in the visible spectrum. The volume ratio of (1:0.2) gave the peak absorption at 0.75 a u. The band gap energy of the blend thin film is 3.58 eV at 375°C in the visible range of wavelength spectrum. It is revealed from the result that the light absorption, broadened absorption spectral range and thermal stability of titanium (iv) oxide film could be enhanced using silver nanoparticles. The results can be therefore used as a guideline for improving the design and fabrication of organic solar cells.
Abstract: This research investigates effect of annealing temperature on the optical properties of titanium dioxide loaded with silver nanoparticles (TiO2: AgNPs) thin films deposited on glass substrate by spin–coating technique. Silver nanoparticles was prepared using laguminosae-paplionodeae extracts as a reducing agent for silver nitrate and commercially a...
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High Responsivity Ultraviolet Photoconductors Based on Epitaxial ZnO Thin Films
Issue:
Volume 7, Issue 1, March 2019
Pages:
6-10
Received:
19 July 2019
Accepted:
31 July 2019
Published:
2 September 2019
Abstract: In this paper, ultraviolet (UV) detection properties of epitaxial ZnO films grown on sapphire substrates with radio-frequency magnetron sputtering is reported. The responsivity (R) of the ZnO photoconductors measured at 325 nm wavelength shows a strong dependence on the incident power (P), i.e., R µ P-k (k = 0.7). A responsivity of 3500 A/W (or a gain of 6000) is obtained at the optical power density of 10-7 W/cm2, and the value decreases to 1 A/W at 10-2 W/cm2. The ultra-high responsivity at the low power regime suggests a long lifetime (order of 10 ms) of carriers. The enhanced carrier lifetime is explained by the preferential capture of holes at the recombination centers that exist in the depletion region around grain boundaries and film surface, and the subsequent separation of photogenerated carriers. The strong dependence of the responsivity on the incident power is attributed to the modulation of space charge region width by the photogenerated holes and the resulting change in carrier lifetime.
Abstract: In this paper, ultraviolet (UV) detection properties of epitaxial ZnO films grown on sapphire substrates with radio-frequency magnetron sputtering is reported. The responsivity (R) of the ZnO photoconductors measured at 325 nm wavelength shows a strong dependence on the incident power (P), i.e., R µ P-k (k = 0.7). A responsivity of 3500 A/W (or a g...
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