Sudha Kartha, C; Vijayakumar, K P; Anita, Warrier R; Sajeesh, T H(Elsevier, February 2, 2010)
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Abstract:
SnS thin films were prepared using automated chemical spray pyrolysis (CSP) technique. Single-phase, p-type,
stoichiometric, SnS films with direct band gap of 1.33 eV and having very high absorption coefficient (N105/cm)
were deposited at substrate temperature of 375 °C. The role of substrate temperature in determining the
optoelectronic and structural properties of SnS films was established and concentration ratios of anionic and
cationic precursor solutions were optimized. n-type SnS samples were also prepared using CSP technique at the
same substrate temperature of 375 °C, which facilitates sequential deposition of SnS homojunction. A
comprehensive analysis of both types of films was done using x-ray diffraction, energy dispersive x-ray analysis,
scanning electron microscopy, atomic force microscopy, optical absorption and electrical measurements.
Deposition temperatures required for growth of other binary sulfide phases of tin such as SnS2, Sn2S3 were also
determined
Sajan, P; Dr. M. Junaid Bushiri(Cochin University of Science and Technology, June 5, 2016)
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Abstract:
The research on nanocrystalline materials have been of great interest for
more than 20 years due to its fundamental properties as well as development of
technology based on it. Non-toxic semiconducting nanocrystals are important
materials with wide range of applications in the areas of biotechnology, medicine,
bio-optics and for the fabrication light emitting and harvesting devices. Majority of
the II-VI semiconductors possess wide band gap along with high iconicity and are
important materials for optoelectronic devices operating under the UV excitation
sources. Among the II-VI semiconductors, ZnS is a material with good optical
transmission in the visible region with large exciton binding energy of about 40
meV. ZnS usually crystallizes in cubic form which is zinc blende or sphalerite and
its hexagonal form is in wurtzite phase. The cubic sphalerite phase of ZnS has a
band gap of 3.68 eV whereas the hexagonal (wurtzite) phase has a band gap of 3.77
eV. Moreover, ZnS is a good host lattice phosphor for photonic applications and
electroluminescent devices because of its wide band gap.
The present thesis deals with the synthesis and photoluminescence studies
of micro and nanostructured ZnS by hydrothermal and solvo-hydrothermal method.
Thesis is also focused on bioimaging application of these materials.