Deposition time and annealing effects on morphological and optical properties of ZnS thin films prepared by chemical bath deposition

Nanocrystalline zinc sulfide (ZnS) thin films are prepared on glass substrates by chemical bath deposition (CBD) methodusing aqueous solutions of zinc chloride, thiourea ammonium hydroxide along with non-toxic complexing agent tri-sodiumcitrate in alkaline medium at 80 °C. The deposition time and annealing effects on the optical and morphological properties arestudied. The morphological, compositional, and optical properties of the films are investigated by scanning electron microscopy(SEM), X-ray energy dispersive spectroscopy (EDAX) and UV-Vis spectroscopy. SEM micrographs exhibit uniform surfacecoverage. UV-Vis (300 nm to 800 nm) spectrophotometric measurements show transparency of the films (transmittance rangingfrom 69 % to 81 %), with a direct allowed energy band gap in the range of 3.87 eV to 4.03 eV. After thermal annealing at 500 °Cfor 120 min, the transmittance increases up to 87 %

Deposition time and annealing effects on morphological and optical properties of ZnS thin films prepared by chemical bath deposition

Nanocrystalline zinc sulfide thin films were prepared on glass substrates by chemical bath deposition method using aqueous solutions of zinc chloride, thiourea ammonium hydroxide along with non-toxic complexing agent trisodium citrate in alkaline medium at 80 °C. The effect of deposition time and annealing on the properties of ZnS thin films was investigated by X-ray diffraction, scanning electron microscopy, optical transmittance spectroscopy and four-point probe method. The X-ray diffraction analysis showed that the samples exhibited cubic sphalerite structure with preferential orientation along 〈2 0 0〉 direction. Scanning electron microscopy micrographs revealed uniform surface coverage, UV-Vis (300 nm to 800 nm) spectrophotometric measurements showed transparency of the films (transmittance ranging from 69 % to 81 %), with a direct allowed energy band gap in the range of 3.87 eV to 4.03 eV. After thermal annealing at 500 °C for 120 min, the transmittance increased up to 87 %. Moreover, the electrical conductivity of the deposited films increased with increasing of the deposition time from 0.35 × 10−4 Ω·cm−1 to 2.7 × 10−4 Ω·cm−1

Deposition time and annealing effects on morphological and optical properties of ZnS thin films prepared by Chemical Bath Deposition

The nanocrystalline Zinc Sulfide (ZnS) thin films are prepared on glass substrates by chemical bath deposition (CBD) method using aqueous solutions of zinc chloride, thiourea ammonium hydroxide along with non-toxic complexing agent tri-sodium citrate in alkaline medium at 80 °C. The deposition time and annealing effects on the optical and morphological properties are studied. The morphological, compositional, and optical properties of films are investigated by scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDAX) and UV-Visible spectroscopy. SEM micrographs exhibit uniform surface coverage. UV–visible (300–800 nm) spectrophotometric measurements show transparency of the films (transmittance ranging from 69 to 81%), with a direct allowed energy band gap in the range of 3.78 – 4.03 eV. After thermal annealing at 500°C for 120 min, the transmittance increases up to 87%

Genome sequence and description of Clostridium niameyense sp. nov., isolated from a human with marasmus in Nigeria

International audienceClostridium niameyense sp. nov. strain MT5 is the type strain of C. niameyense sp. nov., a new species within the genus Clostridia. C. niameyense is a Gram-positive, anaerobic bacillus. The strain MT5 (= CSUR P1468 = DSMZ 100441), whose genome is described here, was isolated from a faecal sample collected from a patient with anorexia and marasmus living in Nigeria. The genome is 2 542 841 bp long with 27.44% G + C content and consists of six scaffolds

Comment on “The Mesozoic Margin of the Maghrebian Tethys in the Rif Belt (Morocco): Evidence for Polyphase Rifting and Related Magmatic Activity” by Gimeno‐Vives et al.

International audienceKey Points : • The main Mesorif gabbros emplaced in a Liassic oceanic domain and do not belong to the Central Atlantic Magmatic Province (CAMP) • CAMP dolerites may occur separately next to the oceanic gabbros in the structurally complex Mesorif zone • The prerift/synrift cover of the distal margin could have emplaced by gravity sliding onto the Mesorif oceanic crus

The State of Planetary and Space Sciences in Africa

Africa has an enormous potential to provide insights into planetary and space sciences, but it has remained largely untapped. Fostering a new generation of scientists promises far-reaching benefits

Africa Initiative for Planetary and Space Sciences

Elevating planetary and space sciences across Africa could help nations reach their development goals. Efforts will require collaboration, creativity, efficient planning, and political will