Sudha Kartha, C; Vijayakumar, K P; Angel, Susan Cherian; Abe, T; Kashiwaba, Y(Elsevier, 2012)
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Abstract:
Thin film solar cells having structure CuInS2/In2S3 were fabricated using chemical spray pyrolysis (CSP) technique
over ITO coated glass. Top electrode was silver film (area 0.05 cm2). Cu/In ratio and S/Cu in the precursor solution
for CuInS2 were fixed as 1.2 and 5 respectively. In/S ratio in the precursor solution for In2S3 was fixed as 1.2/8. An
efficiency of 0.6% (fill factor -37.6%) was obtained. Cu diffusion to the In2S3 layer, which deteriorates junction
properties, is inevitable in CuInS2/In2S3 cell. So to decrease this effect and to ensure a Cu-free In2S3 layer at the top of
the cell, Cu/In ratio was reduced to 1. Then a remarkable increase in short circuit current density was occurred from 3
mA/cm2 to 14.8 mA/cm2 and an efficiency of 2.13% was achieved. Also when In/S ratio was altered to 1.2/12, the
short circuit current density increased to 17.8 mA/cm2 with an improved fill factor of 32% and efficiency remaining
as 2%. Thus Cu/In and In/S ratios in the precursor solutions play a crucial role in determining the cell parameters
Urmila, K. S; Dr. Pradeep, B.(Cochin University of Science and Technology, August 6, 2016)
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Abstract:
The use of energy in our day to day life has grown exponentially and
conserving energy to meet the world’s escalating energy demands is the need of
the hour. During the past decade there is a heightened awareness all over the
world that the production costs of energy from coal, oil and natural gas is
increasingly higher and at the same time the energy technologies involving their
use are contributing to a serious rise in the greenhouse gases in the environment
and a consequent global warming. As a result, more attention is focused on the
utilization of clean energy technologies, especially solar energy which has a
great potential to meet a large fraction of world’s energy demands using
photovoltaics (PV). The heart of the PV system that efficiently convert sunlight
directly into electricity through photovoltaic effect is the solar cell - originally
developed for space applications in the 1950s, are now used in consumer
products, mounted on roofs of houses or assembled into large power stations.
Subin Thomas; Dr. K. Rajeev Kumar(Cochin University of Science and Technology, November 11, 2015)
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Abstract:
The semiconductor industry's urge towards faster, smaller and cheaper
integrated circuits has lead the industry to smaller node devices. The integrated
circuits that are now under volume production belong to 22 nm
and 14 nm technology nodes. In 2007 the 45 nm technology came with
the revolutionary high- /metal gate structure. 22 nm technology utilizes
fully depleted tri-gate transistor structure. The 14 nm technology is a
continuation of the 22 nm technology. Intel is using second generation
tri-gate technology in 14 nm devices. After 14 nm, the semiconductor industry
is expected to continue the scaling with 10 nm devices followed by
7 nm. Recently, IBM has announced successful production of 7 nm node
test chips. This is the fashion how nanoelectronics industry is proceeding
with its scaling trend.
For the present node of technologies selective deposition and selective removal
of the materials are required. Atomic layer deposition and the
atomic layer etching are the respective techniques used for selective deposition
and selective removal. Atomic layer deposition still remains as
a futuristic manufacturing approach that deposits materials and lms in
exact places. In addition to the nano/microelectronics industry, ALD is
also widening its application areas and acceptance. The usage of ALD
equipments in industry exhibits a diversi cation trend. With this trend,
large area, batch processing, particle ALD and plasma enhanced like ALD
equipments are becoming prominent in industrial applications. In this
work, the development of an atomic layer deposition tool with microwave
plasma capability is described, which is a ordable even for lightly funded
research labs.
Anju, S. G; Dr. Suguna Yesodharan(Cochin University of Science and Technology, November , 2015)
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Abstract:
The term ‘water pollution’ broadly refers to the contamination of
water and water bodies (e.g. lakes, rivers, oceans, groundwater etc).
Water pollution occurs when pollutants are discharged directly or
indirectly into water bodies without adequate treatment to remove the
harmful contaminants. This affects not only the plants and organisms
living in these bodies of water but also the entire natural biological
communities and the biodiversity.Advanced Oxidation Processes (AOPs) have been tested as
environment-friendly techniques for the treatment of contaminated water,
in view of their ability to convert pollutants into harmless end products.
These techniques refer to a set of treatment procedures designed to
remove organic or inorganic contaminants in wastewater by oxidation.
The contaminants are oxidized by different reagents such as air, oxygen,
ozone, and hydrogen peroxide which are introduced in precise, preprogrammed
dosages, sequences and combinations under appropriate
conditions. The procedure when combined with light in presence of
catalyst is known as photocatalysis. When ultrasound (US) is used as the
energy source, the process is referred as sonication. Sonication in
presence of catalyst is referred as sonocatalysis. Of late, combination of
light and sound as energy sources has been tested for the decontamination
of wastewater in the presence of suitable catalyst. In this case, the process
is referred as sonophotocatalysis. These AOPs are specially advantageous
in pollution control and waste water treatment because unlike many other
technologies, they do not just transfer the pollutant from one phase to another but completely degrade them into innocuous substances such as
CO2 and H2O.